the vivarium - issue 3 / volume 2

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Editorial

Thank you for picking up this issue of The Vi-varium and Aquarium News. As the summer

months wind down and temperatures begin to drop, we here at Zoo Med Labs, find ourselves as busy as ever. Our reptiles bred in the spring, laid eggs in the summer, and their eggs are hatching now. We are busy building new habitats for hatchlings, upgrading enclosures for growing juveniles, and preparing all of the animals for the cooler winter months ahead. Animal care-takers have been pleased to have several ani-mals hatch including a couple of new species for Zoo Med. This has been our first year to hatch Marginated Tortoises (Testudo marginata) and the endangered Forsten’s Tortoise (Indotestudo forstenii.) Show season is in full swing with rep-tile and aquarium shows and expos almost every weekend. In June, I had the opportunity to attend the In-ternational Betta Congress’s (IBC) Annual Con-vention held in San Jose, California. For anyone who has never been to a Betta show, you really should think about attending one. Fish are ship-

ped in by breeders from all over the world and judged against the standards set forth by the IBC. The “Fish Room” is filled with hundreds of fish of all different colors and varieties. Judges spend hours evaluating the fish focusing on their fins, body, and attitude to determine winners of each class and finally the Best of Show. Once the judging is complete, winning fish are announced and breeders are recognized for their breeding and showing accomplishments throughout the past year at the annual awards banquet. Finally, many of the fish that breeders worked so hard to produce are auctioned off to other hopeful cham-pions, new breeders, or people looking for a new, beautiful pet. The Betta breeders at this conven-tion display such an incredible level of enthusi-asm for their hobby that I cannot help but be ins-pired. The delight that is expressed as breeders discuss their animals is clearly worth the months they have devoted to the caring for these specta-cular little fish. It was the fascination and passion that a few people had for Bettas that prompted them to start a community focused on these little gems. Over fifty years later, that shared interest continues to bring Betta hobbyists together with a strong sense of camaraderie and allows them to share knowledge, experience, and ideas. Between caring for animals, attending shows and conferences, and other summertime activi-ties, there is little time or much else, but I hope that in your downtime, you will enjoy reading this issue of The Vivarium and Aquarium News!

Ashley RademacherAnimal Care and Education CoordinatorZoo Med Labs

Contents

Bearded Agamas are always in

Extra males, extra females, pairs ??!!

Filefish - useful and neat

A ghost fish ?!

the Chinese Firebelly Newt

The nano terrarium - part 3

NEW ON THE MARKET!

The proper way to keep young tortoises

4-9

10-14

15-19

20-24

25-27

28-32

33-40

41-48

The Vivarium - Issue 3 Vol. 24

Bearded Agamas are always in

More than 30 years ago Australia imposed a total ban on the export of reptiles and amphibians. As a result, since then peo-ple have resorted to keeping popular spe-cies available via captive breeding. This has worked very well for all the affected species, but none so successfully as the Bearded Agama. by Thorsten Holtmann

Bearded Agamas live a hard life in the wild. They are true desert dwellers that suffer a

constant lack of food and water. They in their turn are an important source of food for carnivores. Bearded Agamas counter these challenges with a variety of strategies: thus they eat pretty much anything that fits into their mouths, get by with very little water, and breed extremely abundantly. This method of survival functions not only in the desert, but also under terrarium conditions. This is one of the basic reasons why the Bearded Ag-ama has become a perfect terrarium occupant.

Naturally tame A second such basic reason is that by nature Bearded Agamas exhibit very little fear of hu-mans and have a rather phlegmatic approach to life. In the wild this behavior helps to conserve valuable energy resources. No animal wastes energy unnecessarily, but for an animal from a habitat with so little food as that of the Bearded Agama to do so would be a senseless invitation to a death sentence. In addition the Bearded Agama bites only rarely, a characteristic that is seen as a positive by the majority of animal owners. There may be individ-ual variations, but normally a Bearded Agama gives plenty of warning by opening its mouth wide, lowering its “beard” in threat, and hissing, before it bites. Interestingly, it has only recently been discovered that Bearded Agamas possess primitive poison glands, whose purpose remains totally unclear at present, however. No signs of poisoning in humans have been described. Thus a bite from a large Bearded Agama may well bleed, but apart from the treatment of the wound with antiseptic usual for any animal bite, no further medicinal measures are required.

Red specimens are a particularly popular cultivated form of Bearded Agama.

The Vivarium - Issue 3 Vol. 2 5


The cute factorIts undemanding nature and tameness have un-doubtedly been important factors in the triumphal progress of the Bearded Agama through the ter-rariums of the world. After all, the Bearded Ag-ama is thought to be the reptile most frequently traded all over the world! But a pleasing appear-ance is also important. And the Bearded Agama offers that in several respects.

Firstly, the Bearded Agama - zoologically speak-ing ”the” Bearded Agama belongs to the species Pogona vitticeps - has the broadest head of all Pogona species. This makes juveniles in par-ticular look particularly charming to us humans. Creatures with large heads instinctively awaken protective urges in humans. This is probably a de-cisive reason why of the remaining seven Pogo-na species, only P. henrylawsoni has achieved any degree of terrarium-hobby importance; the other species are maintained only by specialists.

Widely distributed and rich in variants In the wild the Bearded Agama is distributed over a large part of the desert regions of eastern central Australia (New South Wales, Northern

Just a reminder of what wild-colored babies look like.

The names used for cultivated forms are very fanciful: this is the Blood Sandfire.


Territory, Queensland, South Australia, Victoria). It is considered completely unendangered in the wild and isn’t included on the IUCN Red List.

Not surprisingly, within this huge distribution re-gion there are local differences in the appearance of the populations. Witten & Coventry (1990) studied a dwarf population from the Big Desert (Victoria), but found that apart from the fact that these specimens attained a head-body length of at most only 7 inches (17.5 cm) as opposed to 10 inches (25 cm) in the other populations studied to date, there were no significant differences that would justify erecting a separate species or even subspecies.

But a wide distribution is almost always a pre-requisite for a completely different phenomenon: the occurrence of cultivated forms. The crossing of individuals from different populations that nev-er encounter one another in the wild leads rel-atively quickly to genetic patterns that manifest externally, including in coloration for example. If such specially colored specimens are then bred together deliberately then the result is cultivated forms like those illustrating this article.

Inbreeding - a problem?The term “inbreeding” always has negative con-notations for amateur breeders. This is because

among humans very close relatives shouldn’t have children together as there is a danger of genetically-induced deformities or illnesses re-sulting. But this is of no concern in animal breed-ing. Without close inbreeding there wouldn’t be a single domestic form of animal, ie no dogs, no cats, no cattle, sheep, or horses, no chickens,

Juvenile of a ”Striped” cultivated form.

Bearded Agamas sometimes threaten a lot, but only very rarely bite.



http://www.usark.org

and no Bearded Agama color forms. The Beard-ed Agama color forms are essentially just as healthy and fit for survival as their wild-colored and wild-living cousins.

Beware of overbreedingYou should, however, be suspicious if Bearded Agamas are offered at knock-down prices. The reproductive rate of Bearded Agamas is very high. Females produce between 11 and 16 eggs in every clutch. Sexual maturity is attained at the age of 2-3 years and females can produce sev-eral clutches per year. And that is precisely the point: even though Bearded Agamas lay eggs, and hence the embryos aren’t nurtured via the uterus as in mammals, the subsequent fitness of the young is nevertheless strongly dependent on the state of health of the mother.

There are short-sighted breeders who see only the chance of a quick profit and treat their fe-males as regular breeding machines. Among en-thusiasts this is known as overbreeding, and the resulting youngsters are very often susceptible to disease and not properly equipped for surviv-al. These phenomena are then, out of ignorance, blamed on “inbreeding”, when in fact inbreeding has nothing at all to do with it.

Responsible animal breeding always involves stringent selection and proper treatment of the

breeding stock. That costs money and hence top quality Bearded Agamas are always somewhat more expensive.

Good quality Bearded Agamas will always pro-vide you with a lot of enjoyment. No other reptile combines robustness, attractiveness, and ease of maintenance in such an ideal manner.

Tricolor cultivated form, ”Rainbow”.

This cultivated form is called ”Cawley”. Photos: Frank Schäfer



What does science have to say about it?

In the past precisely the opposite has been stat-ed in several scientific works, namely that an

excess of males is much easier on the females.These studies were conducted in the 1940s and 1950s. The object of the work was to establish the scientific prerequisites for the optimal labo-ratory maintenance of Platies and Swordtails, as it had been discovered that certain crosses between Platy and Swordtail resulted in cancers in the offspring. This was a revolutionary discov-ery that permitted a giant leap forward in cancer research. Millions of people afflicted with cancer owe their lives to the knowledge obtained from these experimental organisms.

It was found that in Platies the aggressive inter-actions between males and females were com-parable, ie females nipped one another just as often as males, and this was, moreover, inde-pendent of whether they were kept in single-sex (male or female) or mixed-sex groups.

Extra males, extra females, pairs ??!!What is the right way to keep Guppy, Platy, & Co?

Although there is nothing to that effect in the aquarium hobby literature on live-bearing toothcarps, current wisdom on the Internet, and even in training manuals for those applying for a pet-trade license, is the abstruse recommendation that live-bearing toothcarps are always best sold in the ratio of one male to three females.

This is based largely on the permanent display and courtship by the males. An excess of females supposedly spreads this pressure more evenly and thus mini-mizes the negative stress on the individ-ual females. by Oliver Helker and Peter Merz

Variatus Platy, Xiphophorus variatus, male with Simpson finnage.


In addition, when Platies and Swordtails are crossed behavioral characteristics are inherited true to type. This means that even Swordtails that owe their coloration to a Platy in-cross exhib-it typical, species-specific Swordtail behavior and are indistinguishable from pure-strain Swordtails in this respect. The same applies to Platies: they always retain their species-specific Platy behav-ior, even when they have Swordtail in-crosses in their ancestry.

What happens with an excess of males?If you stop and think a little about why an excess of males should be easier on the females, then you can establish this quite simply for yourself without needing to read any dry studies or need-ing to be a biologist at all.

If you keep several males in an aquarium, then each male will try to attract the attention of fe-males and secure a harem for himself by com-peting with other males. The majority of the time the males are busy among themselves and don’t have much opportunity to display to a female. The moment a male starts to display in front of a female then his neighbor comes shooting over to steal the female. Because the two males then have eyes only for their opponent, the oppressed lady has the ideal opportunity to make herself scarce in the event that she isn’t really ready to mate.

An excess of males is a good thing!But there is an additional reason why an excess of males is an advantage: a single male can afford to be prodigal with his sperm, as he can inseminate several females within a short time

Endler’s Guppy ”Vienna Emerald”.


without problem. There is no need to be fussy about choice of partner. As a result, every female within reach is courted as a rule and no selection takes place.

Matters are quite different in the case of the fe-males, which can bring only a limited number of young into the world every 4-6 weeks. In addition the production of eggs abstracts energy and nu-trients from the body of the mother.

The female must thus make a precise choice as to who is going to be the father of her offspring. If possible this will always be the largest, most beautiful, and strongest male, to provide her off-spring with the best possible genetic inheritance.

Only large, strong, and healthy males are capa-ble of out-competing a large number of compet-itors. Because these characteristics are passed on to the offspring, such a male is, of course, the optimal choice in order to produce vigorous off-

spring that are, above all, likely to survive.

In order to keep a strain of livebearers healthy and vital in the aquarium for a long time, it is best to place the largest possible number of males in the tank. (The actual number will depend on the tank size.) That way the best genes will prevail. The weaker males, by contrast, will hardly ever get to breed. The females will produce strong, vital young.

Species awareness requiredThe livebearers regularly found in the trade be-long to several species, and knowledge about these is important, as each species has its own specific behavior and that too must be taken into consideration when deciding on the numbers of males and females.

GuppiesAll the guppies in the aquarium belong to the species Poecilia reticulata and P. wingei, as well

Male platy, Xiphophorus maculatus, ”Bleeding Heart” cultivated form.



as hybrids between them. What has been said above applies unreservedly to all guppies: an ex-cess of males has very beneficial effects on the strain.

PlatiesThe platies maintained in the aquarium belong to two species: Xiphophorus maculatus and X. variatus. They aren’t hybridized and both species breed true, at least as regards behavior. Again, there is an unreserved recommendation applying to both platy species: they should be kept in pairs or with an excess of males.

SwordtailsPlaties and swordtails belong to the same genus, Xiphophorus, which contains a total of 28 species. But the only swordtail in the trade is Xiphophorus hellerii, and the other species are so seldom maintained as to count as rarities. Swordtail males are, unlike the guppies and platies, very aggressive among themselves. Dominant males can oppress subordinate individuals to such an extent that they die as a result. For this reason only one male should be kept in standard sizes of aquaria up to 24 inches (60 cm) in length, but can generally be combined with several females.

Green Swordtail, Xiphophorus hellerii, spotted wild form ”Guentheri”.

The species-specific dorsal-fin forms of adult molly males.

Poecilia sphenops

Poecilia latipinna

Poecilia velifera


Perhaps this is the source of the incorrect blanket recommendation of keeping livebearers in the ratio 1:3. In sufficiently large aquaria that permit the maintenance of 10-15 individuals, however, swordtails too can be kept with five or more males together. But there should never be fewer than five males, as otherwise the dominant individual will seriously harass members of his own sex, even in very large aquaria.

MolliesEssentially, mollies trace their ancestry back to three original species: the Common or Short-fin Molly Poecilia sphenops, the Sailfin Molly P. latipinna, and the Giant Sailfin Molly P. velifera. While the Shortfin Molly should be kept like the guppies and platies, the other two species should be treated like swordtails. The three species can be distinguished by the form of the erect dorsal fin in males, in other words when the latter are displaying among themselves.

Animal welfareThe argument that females are too severely stressed by the constant attentions of ready-to-mate males when there is an excess of the latter, is anthropomorphic and incorrect from a scientif-ic viewpoint. So it is of no relevance in terms of animal welfare.

Because males and females of livebearing tooth-carp species come into the world roughly in the ratio of 1:1 and all the specimens found in the trade are exclusively captive-bred, selling them in pairs must be regarded as optimal from an an-imal welfare viewpoint, as otherwise what is to become of all the superfluous specimens? So the conclusion to be drawn from all this must be, buy platies, swordtails, mollies, and guppies as pairs or with an excess of males.

This attractive Marbled Molly belongs to the species Poecilia sphenops (Shortfin Molly). All photos: Frank Schäfer

It was this dentition and above all the associated feeding habits that first brought the filefish to the attention of marine aquarists, as some species are especially fond of consuming the “glass ros-es” (Aiptasia) that are such a nuisance in the cor-al-reef aquarium. However, these filefish species are not trophic specialists. The species currently most frequently offered for combating Aiptasia is Acreichthys tomentosus, which has become so popular that it has acquired a whole set of com-mon names – Aiptasia-Eating Filefish, Bristletail Filefish, Matted Filefish.

Filefish - useful and neat

The filefish (Monacanthidae) are a fam-ily in the puffer assemblage (Tetraodon-tiformes), which means that their closest relatives include puffers, porcupinefish, boxfish, and triggerfish. Externally they are most similar to the triggers, with which they share a locking mechanism for the first dorsal-fin spine. This mech-anism serves to lock the dorsal-fin spine firmly in place. While the majority of the puffer assemblage have powerful biting tools with which to crack open mussels, snails, sea urchins, and the like, the den-tition of the filefish is designed solely for feeding on small organisms. by Matthias Reising

Oxymonacanthus longirostris


The Bristletail Filefish - the most popular of them allThis species is a very common and widespread fish. It occurs in large parts of the western In-do-Pacific and received its scientific name back in 1758 from the father of zoological nomencla-ture, Carl von Linné. With a maximum size of 4.75 inches (12 cm; aquarium specimens, which are known to live considerably longer than those living in the wild, may perhaps grow somewhat larger), it is ideally suited to aquarium main-tenance. Like almost all members of the puff-er group, the Bristletail Filefish is not an active swimmer and hence doesn‘t require much swim-ming space. Its coloration is such that it may easily be overlooked. As can be seen from the photos, it usually comes in assorted shades of

Juvenile Acreichthys tomentosus are exceptionally dainty.


brown and gray. Anyone who takes the time to observe these fish more closely will find that they are capable of rapid, mood-dependent changes of color, and that immediately makes them more interesting. They can even turn bright green!

The Bristletail Filefish is very fond of eating Aip-tasia, but will often also consume other sessile invertebrates. Hence long-term maintenance in the coral-reef aquarium is only sometimes pos-sible, as there are considerable differences in the habits of individuals. The ideal is to have a fish-only tank available as well as the reef aquar-ium, so that the Acreichthys tomentosus can be transferred to the former when the Aiptasia have all been eaten. Because the total eradication of these survival specialists can be achieved only with difficulty, the filefish needs to be returned to the reef aquarium from time to time. So it is defi-nitely not a good idea to give it away after the first plague has been eliminated.

The Harlequin Filefish - the loveliest of them allOnly a few of the roughly 100 filefish species currently known are noted for their bright coloration. There are two exceptions: the Harlequin Filefish (Oxymonacanthus longirostris and O. halli). The two species look so similar that until the 1950s they were thought to be a single species. Only then was it realized that the harlequin filefish from the Red Sea were different to those from the Indo-Pacific, and they were described as O. halli. Both these species are again common and widespread and grow to only 4-4.75 inches (10-12 cm) long, but unfortunately they cannot be recommended for the marine hobby in general. They are extreme trophic specialists that feed exclusively on polyps of the stony coral genus Acropora in the wild. In addition these fish are sociable, such that specimens kept singly waste away. It is in fact possible to get Harlequin Filefish used to substitute foods (E. Thaler managed it with frozen glassworms,

Acreichthys tomentosus, adult specimen.

which she placed in dead Acropora branches using forceps). Such acclimated fish may even spawn in the aquarium, but difficult species like this are best reserved for specialists who know precisely what they are letting themselves in for. Because, as already mentioned, these fish are common and widespread, it isn’t a problem to import them when required.

The Scribbled Filefish - the largest of them allThe majority of tropical filefish remain manageably small and can be purchased without too much thought as long as a fish tank is available, because the main distribution of the somewhat larger filefish lies in subtropical waters where no exportation for the aquarium hobby takes place. Here the fish are so common that they are even

caught as food. While the majority of the members of the puffer assemblage mentioned earlier are deadly poisonous when consumed, this doesn’t apply to the filefish. At least not in most cases - but the Scribbled Filefish (Alutherus scriptus), a species distributed worldwide throughout the tropics and which can grow up to 43 inches (110 cm) long, sometimes takes its revenge on people who eat it via ciguatera poisoning. This can arise through the consumption of otherwise non-toxic fish if the poison from an alga has accumulated in their flesh. Aquarists don’t normally eat their pets, of course. It is nevertheless important to be familiar with the Scribbled Filefish in order to avoid accidentally buying it as a dainty youngster. The long caudal fin makes the species easy to recognize. In public aquaria, however, the Scribbled Filefish is, of course, a real eye-catcher,

Alutherus scriptus, male. This species grows to more than 40 inches (100 cm) long and is the largest filefish.

Pervagor janthinosoma


The Vivarium - Issue 3 Vol. 2 19as it is very attractively colored. The species presents no difficulties as regards feeding, as it is a rather opportunistic omnivore.

The Blackbar Filefish - the most interesting of them all for the hobby? This filefish species, correctly termed Pervagor janthinosoma, is again widely distributed in the Indo-Pacific. It too grows to only around 4.75-5.5 inches (12-14 cm) long. The Blackbar Filefish is significantly more aggressive towards conspecif-ics than the previously mentioned species, which can readily be housed with conspecifics, and in the case of Oxymonacanthus even should be. Nevertheless one should always try to put pairs of this species together. So far not much has been published on the Blackbar Filefish. There are re-ports that the species is difficult to get to feed, but these are mostly ancient (before 1980) and it isn’t completely clear whether the problems may not have been down to inappropriate treatment of the fish. When adult (around 3-4 inches (8 -10 cm) in length upwards) the Blackbar Filefish usu-ally lives in pairs. The male can be recognized by rough, bristle-like scale structures on the caudal peduncle, which are absent in females. Should Pervagor janthinosoma turn out to be a good Aip-tasia-eliminator, which also looks attractive and can be bred, then it would certainly be the dream filefish for the reef hobby. However, it must be stressed once again that there are as yet far too few experience-based reports available on this fish, let alone on breeding it.

Breeding essentially possible!Filefish have proved fairly amendable to attempts to breed them. Even the extremely tricky Oxymo-nacanthus have already spawned in the aquar-ium. However the Bristletail Filefish is probably the only species that has so far been bred with any degree of success worth mentioning. Unfor-tunately the sexes cannot be distinguished in the youngsters usually available in the trade, and only with the arrival of sexual maturity do males develop the spiny scales on the caudal peduncle, already mentioned for Pervagor, that have led to the popular name of Bristletail Filefish.

Hence it is best to obtain 5-6 youngsters and wait for them to form pairs. The fish spawn in pits in the bottom that are stringently defended by the male. The young will readily take the usual plankton (rotifers, plus phytoplankton) cultivated by private breeders, the main difficulty in rearing being maintaining a sufficiently high food density - the young filefish should always literally be up to their fins in food - and at the same time the water quality mustn’t be allowed to deteriorate too much.

All in all, filefish are interesting aquarium fish, about which there is still much to learn. And we haven’t even discussed here the fact that there are filefish that imitate the highly poisonous puff-ers. But more of that another time, maybe …

Oxymonacanthus longirostris is gorgeous, but suitable only for experts.


They are in fact albinos of one of the most an-cient fish species on our planet, a so-called

living fossil, namely the Senegal Bichir, Polypter-us senegalus. Fossil finds of this species have been discovered that purportedly date from 60 million years ago, a time when the dinosaurs still ruled the Earth!

Inventors of gene technology The dinosaurs are long gone, but the bichirs re-main. Their existence - at present 13 species are recognized - is a mystery. Why have they sur-vived for so long, even though entire classes of animals have disappeared from our planet within much shorter time frames? And how have they adapted to the repeated dramatic changes in en-vironmental conditions? The last question at least

has been answered by DNA studies - through hy-bridization! Their genes clearly indicate that var-ious species of bichir have repeatedly crossed with one another. In fact the hybrids that result from such crosses are unable to breed togeth-er (at least there is no indication that anything of the sort takes place in the wild), but they are able to mate with the parent species. In domestic animals this is termed back-crossing. The result is that new genetic material is introduced into the population, apparently fitting it for the battle for survival. So it seems that gene technology isn’t a human invention, some fish have been practicing it for millions of years.

A ghost fish ?!

For some time now there have been strange, snow-white to ivory-colored, ci-gar-shaped fish with ruby-red eyes in the trade. So what are they? by Wolfgang Löll

Albino Senegal Bichirs are bred commercially as aquarium fish in Asia.

Half-grown wild-caught Senegal Bichir from Nigeria.

Survival specialistsIn addition a part has undoubtedly been played by the legendary “survival pack” that Mother Nature has created for the bichirs. Their construction is so designed that it would appear impossible to improve in any way. Thus these fish breathe not only via gills, but also with lungs. Their bodies are enclosed in a chain-mail shirt of rhomboid bony plates termed ganoid scales, which make these fish almost invulnerable (at least compared with the delicate scales of most other fish). Bi-chirs are exclusively carnivorous, and, because

they are poikilothermic and hence do not - unlike us humans - have to use the majority of the ener-gy obtained from food in order to maintain body temperature, they can get by for a long time on little food. For their own part, bichirs have little at-traction for predators. Their individual little dorsal fins, the so-called finlets, are razor-sharp - and will truly scratch if swallowed! Human medicine hasn’t yet turned its attention to the bichirs, but it seems very likely that these survival specialists may even offer means of overcoming cancer and pathogenic viruses.

This dwarf form of the Senegal bichir grows to barely 4 inches (10 cm) long.

Very young P. senegalus are striped and have external gills like newts.

A full-grown wild-caught male measuring some-what over 10 inches (25 cm) in length.


22

Little dragonsBichirs are readily maintained in the aquarium and make interesting objects of study. But because they are predators, in Europe they are maintained mainly by specialists. By contrast they are very popular in Asia. They are reminiscent

of the dragon, the mythical beast that brings good luck. South-East Asia is also the source of the albino tank-breds of Polypterus senegalus. Albino creatures exercise a great fascination for humans, not only in Asia, but also here in the west. Just think of the myths and legends


a fully albino specimen with typical red eyes.

An albino peering curiously at the world.

regarding white hinds. Unicorns are always portrayed as white. And in his novel Moby Dick Herman Melville chose a white Sperm Whale as a symbol of invincible Nature, opposition to which always results in harm.

The albino cultivated forms should also be viewed in this context. They divide aquarists into two camps - those who abhor them as supernu-merary unnatural creations and those who are fascinated by their pure white color.

Facts about the Senegal BichirPolypterus senegalus is widespread in West and Central Africa. Wild-caught imports usually come from Nigeria. The species varies little in col-or, and looks essentially the same everywhere - gray with a few little black spots. The fins are whitish gray, except in a dwarf form from Nigeria that exhibits sexual dimorphism at just 4 inches (10 cm) in length and has yellowish fins. Normal-ly maximum length is around 12 inches (30 cm) in the Senegal Bichir, and references to different sizes in the literature are the result of confusion with other bichir species. Sexual maturity is at-tained at a length of around 8 inches (20 cm) and an age of about two years. Males are smaller and slimmer than females and have a much-en-larged anal fin that is wrapped around the female during spawning to form a “bowl” in which the millet-sized eggs are caught and fertilized. The

young that hatch from the eggs look totally dif-ferent to the parents and are more reminiscent of newt tadpoles, as they have bushy external gills. In addition very young Senegal Bichirs are striped brown and white, but they soon lose this juvenile pattern at a length of around 1.5 inches (4 cm).

This elderly female has become almost black with age.

Portrait of the old black female, a so-called melano;



Senegal Bichirs in the aquariumThe maintenance of these fish is very easy. They make no demands at all regarding water chem-istry, and can be kept in any water suitable for humans to drink. Senegal Bichirs are complete-ly peaceful among themselves and towards any fish too large to be viewed as food. They are best kept in a small group of 4-6 specimens. The aquarium for this should be around 48 inch-es (120 cm) long. The decor is of no importance to the bichirs but these rather stiff-bodied fish should be allowed sufficient swimming space and the tank shouldn’t be too densely planted. A moderate current, a substrate of soft sand, mut-ed light (bichirs are crepuscular/nocturnal), and a water temperature of 75-82 °F (24-28 °C) (some-times lower to stimulate breeding, but best if the temperature doesn’t drop below 64 °F (18 °C)) will ensure the well-being of Senegal bichirs. The best food to offer is larger frozen foods (mussels, shrimps, smelt, cuttlefish, etc), plus occasional live food in the form of earthworms. Around 25% of the water should be changed weekly.

For breeding the water changes should cease for a number of weeks and the usual maintenance temperature be simultaneously lowered. Then several large water changes (80-90% of the tank volume) should be performed in rapid succession (at intervals of 1-2 days), if possible using some-what softer water. Finally the temperature should be raised to around 82 °F (28 °C).

The males drive rather vigorously and display with the anal fin spread wide, and the eggs are scattered loose in the tank. Depending on the size of the female there may be several hundred eggs.

Some specimens are yellowish with black eyes, and are termed lutinos. All Photos: Frank Schäfer

Polypterus means ”many-finned” referring to the dorsal finlets.senegalus means ”from Senegal”.

Lexicon: Bichirs

Cool: the Chinese Firebelly Newt

The tail is longer in females, which grow to a total length of around 3 inches (8 cm).

Males grow to around 2.5 inches (6 cm) long, and have a shorter tail and a swollen cloaca.

In the past the maintenance

and breeding of salamanders

and newts was very popular

with terrarium enthusiasts,

but unfortunately only a few

specialists work with them

nowadays. This is because the

vast majority of salamanders and

newts do well in the long term

only if kept at low temperatures

(50-59°F (10-15°C)). In warmer

conditions they aestivate, and

nowadays the temperature in

our homes is always on the

warm side. But luckily there is

the Chinese Firebelly Newt.

The warm-blooded newt

The Chinese Firebelly Newt

comes from eastern central

China, where it is very common.

The peculiarity of the Chinese

Firebelly Newt is that it prefers

temperatures between 68 and

77 °F (20 and 25 °C). This

makes it the newt best suited

for maintenance in the home.

In water these newts find

their food by smell, and so

they will also eat dry and

frozen fish foods in water.

On land, by contrast, these

newts eat only living food

that is still moving, for

example worms, as they

can’t smell well out of

water and use their eyes

to search for food.

25


The upper side of the Chinese Firebelly

Newt is uniform black-brown, the underside

bright red.

Life in water and on land

Newts, salamanders, frogs, and toads are termed

amphibians, which translates as “those that live

on both sides”. The majority of species live in

water at breeding time and the rest of the

year on land. However, the Chinese Firebelly

Newt almost always lives in water. Only when

conditions get very warm (significantly over

77 °F (25 °C)) does it leave the water. It can

even drown if no land area is available! On land

the skin becomes smooth and water-repellent,

and the newt looks much smaller and thinner.

Although these newts are active all day in water,

on land they become nocturnal and spend the

day in hiding.

Other things you need to know....

The scientific name of the Chinese Firebelly Newt is Cynops orientalis, which translates as ”oriental dog-eye”. Males can most easily be recognized by their shorter tails. Chinese Firebelly Newts lay eggs, which are produced singly or in batches of 3-4 and are then hidden among the leaves of aquatic plants by the female, who uses her hind legs to fold the leaves to create a bag. The male displays in front of the female while fanning his scent towards her with his tail.

26


Dear Parents,Children love newts. But you must make it clear to your child right from the start that newts should be handled only when absolutely necessary. Otherwise the very delicate skin of the newt may be damaged, leading to infection or even the death of the newt.

Setting up the terrarium The terrarium for these newts should consist of an aquarium measuring at least 16 x 12 x 12 inches (40 x 30 x 30 cm), and larger is better. It should be filled to a depth of 8 inches (20 cm) with water, and the water area should be set up in the same way as an aquarium for fish. If possible avoid using a motorized filter and use an air-driven type instead. There is too great a risk of injury to newts if motorized filters are used, plus the motor emits heat.

To create a land area, place a piece of floating cork bark in the aquarium. If the newts spend a lot of time sitting on land (ie on the cork) then they should be placed in a moist terrarium with moss and decaying wood; a water dish filled with fresh water should al-ways be available. If the newts spend all their time sit-ting in the water dish then they can be transferred back to the original terrarium.

A terrarium for newts should always be tightly covered and escape-proof, as they can even climb up vertical glass surfaces! The terrarium should never stand in the sun, and the temperature in the terrarium should ideally be 59-72 °F (15-22 °C). These newts require a winter rest at around 50 °F (10 °C) from January to March.

Maintenance tasksBecause they are poikilothermic and not very active, newts are very inexpensive to care for. It is perfectly adequate to feed them every other day, and as a gen-eral rule of thumb it is better to feed too little than too much! As with an aquarium, perform a weekly partial water change of around 1/4 - 1/3 of the water volume. The new water should be roughly the same tempera-ture as the old, though 3-5 °F (2-3 °C) cooler will be tolerated and do no harm. When you go on vacation it is better not to feed at all for 2-3 weeks (this will do no harm) than to risk over-feeding, which can result in the death of the newts.

HazardsYour child can learn the normal rules of hygiene through dealing with these newts, ie washing hands after work-ing on the terrarium. There are no known diseases that can be transmitted to humans by newts. These newts are completely harmless! It must be stressed again that newts should never be handled unless necessary; handling is unpleasant for them and can, in the worst case scenario, result in their death.

After handling any newt, salamander, frog, or toad, always wash your hands. Never rub your eyes af-ter handling any amphibian and children under the age of 12 should always be supervised when han-dling or providing care for pet amphibians.

INFOBOX FOR PARENTS!i



This terrarium type will serve for the mainte-nance and breeding of creatures from deserts

and semi-deserts. Heat-loving and/or diurnally active species that enjoy sunbathing should not be kept in the nano terrarium for various reasons (extreme danger of overheating!). The most suit-able species are crepuscular and nocturnal, and in the wild pass the heat of the day in cool hid-ing-places with an element of ground moisture, but there are also a number of diurnal species that are suitable for the dry nano terrarium. The decoration of such a terrarium must take all this into account. Thus part of the bottom pan should be partitioned off with a strip of glass glued in place with silicone so as to be watertight. This part should be filled with a peat-sand mix (1:1,

see part 2) and always kept slightly moist. This will act as a daytime retreat and somewhere to lay eggs. It is wise to use a small herbaceous plant to monitor the moisture level – the extent to which it thrives will show whether the correct de-gree of moisture is being maintained. Too much is just as bad as too little. Numerous Mediterra-nean plants are suitable, and thyme in particu-lar looks very natural. Unfortunately these plants require an exceptional amount of light, so if they are used it will be necessary to use bright light even if not actually required by the livestock. Small Kalanchoe, Sanseveria, and a number of Sedum species are simultaneously attractive and less light-hungry, but not as good as micro-climate indicators because of their succulent leaf structure. Under no circumstances should spiny cacti or Euphorbia be used. Due to the limited space in a nano terrarium there would be too great a danger of injury to both owner and occu-pants. In addition it should be borne in mind that all Euphorbia are poisonous.

In the moist area there should always be a stone to create a cave or piece of bark beneath which the terrarium occupants can hide during the day. Many desert-dwelling species regulate their moisture content via their skin. There should also

The nano terrarium - part 3The dry nano terrarium

Essentially a nano terrarium (from the Latin nanus = small) is suitable for the maintenance and breeding of a host of invertebrate creatures. But there are also a number of amphibians and reptiles that are eminently suitable for housing in a nano terrarium. by Thorsten Reuter

Bufo debilis Photo: Frank Teigler


be room in the moist area for the small water dish that should always be provided as a fundamen-tal. The rest of the tank bottom should first of all be covered with a layer of styrofoam about 1/2 inch (1 cm) thick, on top of which rockwork can be constructed. Then finally the substrate can be added. Depending on the species kept, this can be fine sand or loamy garden soil. If using sand it should be borne in mind that only rounded river sand should be used and not sharp sand such as is employed in the building trade. The terrarium hobby trade offers a good range but not every-thing that looks good is also practical. Above all the substrate should be relatively dust-free. If the sand becomes moist then it should not form rock-hard clumps when it dries out again. In addition the sand should not be too fine, as otherwise the livestock may be afflicted by serious respirato-ry diseases. Finally, the occupants will not look good, even if no harm results, if they constant-ly appear freshly powdered. Some dry branches will complete the décor.

The livestockAlthough this may seem astonishing to the lay-man, there are amphibians that live in deserts. The incredibly pretty dwarf toad Bufo debilis from North America is suitable for a nano terrarium. A number of dwarf geckos make charming occu-pants, just one example being the fabulous Lygo-dactylus species. In contrast to all the other spe-cies discussed here they are diurnal. In the wild they live on tree-trunks and in dry-stone walls, etc. They don’t need a spot-lamp for the heat

It goes without saying that a nano terrarium is particularly suitable for rearing youngsters. Here a newly-hatched Lygodactylus kimhowelli on the finger of the photographer. Photo: F. Schäfer

Lygodactylus wiliamsi Photo: F. Schäfer

The Vivarium - Issue 3 Vol. 2 31regulation of their bodies, but the terrarium must be brightly illuminated. The daytime temperature should attain around 82 °F (28 °C), while at night it may drop to 59 °F (15 °C), though that is unlike-ly to be achieved in the living-room. The nightly temperature drop will occur automatically when the lighting is switched off. It is extremely import-ant to run any nano terrarium intended for Lygo-dactylus species for a number of weeks without occupants in order to be able to experiment with the lighting to some degree until the desired opti-mal microclimate is established. The tiny geckos of the genus Tropiocolotes, which are regularly imported from Egypt, are ideal for maintenance in the nano terrarium. The semi-desert Steno-dactylus species also remain small and are well suited to the nano terrarium. Given the enormous number of gecko species it is essential to obtain

precise information regarding maximum length, they should grow no longer than 4 inches (10 cm) (half of this being tail) if they are to be kept in a nano terrarium. Please bear in mind that mem-bership of the genus doesn’t necessarily dictate anything regarding ecological requirements.

A number of snake species have likewise adapt-ed to life in the desert, including numerous dwarf species. The little Lythorhynchus diadema from Egypt is regularly to be found in the trade. It eats new-born mice. A number of North American species have evolved as insectivores, and in ad-dition are exceptionally attractive. The gorgeous Chionactis occipitalis occasionally turns up in the trade.

Stenodactylus sthenodactylus, a dwarf gecko from Egypt. Photo: Frank Schäfer

Concluding observationsThere are no legal requirements regarding the minimum size of a terrarium. However, we rec-ommend that for the reasons detailed above (mi-croclimate!) the bottom area should not be sig-nificantly less than 12 x 12 inches (30 x 30 cm).The height will be dictated by the habits of the livestock to be maintained. A height of 12 inch-es (30 cm) is sufficient for bottom-dwellers, while species that are vertically oriented are better giv-en 16 or 20 inches (40 or 50 cm). In the case of public collections the “minimum requirements for the maintenance of reptiles” are usually utilized as a measuring stick by veterinary officials. As al-ready stated, these have no legal force, but they do generally offer some useful hints. In the case of lizards the criterion used is the head-body length (HBL; ie not including the tail!). For active diurnal lizards dimensions of 5 x 4 x 4 x HBL are laid down for one specimen, and 15% for each additional specimen. For example, Scincella lat-eralis attains an HBL of 1.5 inches (4 cm; total length around 4 inches/10 cm),so in this case the minimum terrarium size would be 20 x 16 x 16 cm (length x width x height) for one specimen, 23 x 18.4 x 18.4 for two individuals, etc. If the species is known to be quarrelsome intraspecifically (see the example of the geckos above), then work on

the basis of HBL x 6 x 6 x 8. But no rule of thumb can replace the “feel” of the keeper. The goal of keeping animals is to observe the most natural behavior possible. Every keeper of wild animals thus has an obligation to experiment in order to provide the optimal maintenance conditions for his or her charges. Quite simply, neither lizards nor amphibians measuring much more than 2 inches (5 cm) HBL should be kept in a nano terrarium. But here too there are exceptions. Species that spend almost all their time lurking (for example some horned frogs), which remain practically immobile if left to their own devices, and need to be kept singly, can generally also be housed in the nano terrarium. It is known that snakes can generally be housed in a very limited space. Obviously active pursuit predators (some Coluber species, etc.) need more room than lurk-ing species. Thus here too the keeper must use his discretion and knowledge. As a rule all dwarf snakes that grow no longer than 16 inches (40 cm) can be kept and bred in the nano terrarium. The “minimum requirements” for the maintenance of the majority of species utilize total length (TL) as the criterion and suggest 1 x 0.5 x 0.5 (length x width x height) all factored by TL.

Tropiocolotes bisharicus Photo: Frank Schäfer


Aguarunichthys torosus

NEW ON THE MARKET!

Aguarunichthys torosus, a very special fish for hobbyists specializing in predatory catfish,

has recently been imported from Peru. This spe-cies wasn’t discovered until 1986. Isn´t it fasci-nating how Nature utilizes the same camouflage mechanism for totally different species from above and below water? The spotted pattern of A. torosus is very similar to the pattern of wild cats from the jungle! A. torosus grows to about 14 inches (35 cm) long.



Betta smaragdina wild

These splendid wild-collected Betta smaragdi-na were imported from Thailand. The males

can rival their domesticated Betta splendens cousins in every respect. Depending on the light, their scales shimmer in a rather greenish or blu-ish emerald hue. The fighting behavior between males is not as intense as between Betta splen-dens males, but nevertheless Betta smaragdina are fish with temperament!

Chitala blanci

For a long time the Asian featherbacks, which have a well-developed dorsal fin, were placed

in the genus Notopterus. Nowadays the genus Notopterus is regarded as monotypic (containing only the single species N. notopterus) and the high-backed forms have been placed in anoth-er genus, namely Chitala. The very attractive species Chitala blanci is currently available in Germany. This featherback, which can attain a maximum length of about 48 inches (120 cm), originates from the basin of the Mekong River in Thailand, Laos, and Cambodia. These fish are gorgeous occupants for large aquariums. Chita-la blanci prefers water with a strong current and avoids quiet water and swamps. All species of

Chitala are predatory fish that have to be fed with robust (frozen) foods. Naturally, small fish are also eaten. The sexes cannot be distinguished externally. Featherbacks are very peaceful to-wards conspecifics and other tankmates too large to be eaten. During the breeding season the fish form pairs and spawn on rocks, wood, etc. The spawn is guarded by the parents. Chi-tala species are able to breath atmospheric air when necessary, so they can survive for quite a long time even in oxygen-poor water. This makes them much sought-after as food fish in the coun-tries where they occur. However, the flesh is full of small bones, so the meat is usually chopped, pressed through a sieve, and used to make meatballs.


Xiphophorus hellerii Vienna Lyra

Even in the wild there is a noticeable tenden-cy for swordtail females to mate only with

the most impressive males, and that is how the „sword“ evolved in swordtails. This fin extension is obviously a pure luxury without any practical use, comparable with the tail in male peacocks.

The only purpose of both appendages is to im-press females. In captivity it is possible for “luxury genes,“ al-ready inherent in the genetic make-up of wild fish, to be expressed even though they cannot become established in the wild for several rea-sons. One of these genes is the lyra factor in swordtails. This gene leads to a prolongation of


all the fins (except the ventrals) in both sexes - even in females! These females find lyra males very attractive but their desire cannot be satisfied by lyra males, as the copulatory organ of male swordtails (the gonopodium) is also a modified fin (the anal fin) and thus much too long for use. You know the saying, “Have you ever tried to play Mikado with cooked spaghetti?”

So normal-finned swordtail males have to be used for breeding. The offspring of the cross between normal-finned and lyra contains only a percent-age of lyra-finned specimens. This makes breed-ing lyra-finned swordtails quite complicated.


Odontamblyopus rubicundus

This goby from the lower reaches of the River Ganges clearly belongs to the category “fac-

es that can be loved only by a mother“. Leaving aside its appearance, this fish, which can attain up to 10 inches (25 cm) in length, is very inter-esting. Care is required regarding possible tank-mates as any fish that fits in its mouth will be swallowed. The victim can be almost half as long as the predator, and no fish will ever escape once grappled by those fangs… However, fish that are too large to be eaten are completely ignored by Odontamblyopus rubicundus.


Synbranchus marmoratus

Marbled Swamp Eels from South America are only very rarely available, and after a

quite long interval a number of juveniles have been imported from Peru. The species attains a maximum length of about 60 inches (1.5 m). These very large individuals are always males, because swamp eels change their sex. Most of them are born female and become male at the age of about 4 years. This type of sex change, which is quite common in marine fish but very unusual for freshwater fish, is called protogynous hermaphroditism. All species of swamp eel can breath atmospheric air and so survive in very ox-ygen-poor water.


Moema cf. ortegai = Moema hellneri

On November 24th, 2003 (the exact date of publication is important, see below!) the sci-

entific description of two new species of killifish from Peru was published. Wilson J. E. M. Cos-ta described and named the two species Moe-ma hellneri and M. ortegai. M. hellneri originates from the Rio Napo drainage, whereas M. ortegai originates from the drainage of the Madre de Dios. The original scientific paper was illustrated only with very poor pictures of preserved speci-mens. The diagnoses of the species were based on features not visible externally, mainly the den-tition and the form of the maxillary bones.

On November 12th, 2003 the description of Moe-ma quiii (no typo!) appeared in the magazine Freshwater and Marine Aquarium (number 12, volume 26). This species originates from the Rio Tambopata, which belongs to the Madre de Dios drainage in Peru. The author of M. quiii was J. H. Huber.

The two authors were obviously unaware of each

other and these simultaneous descriptions sub-sequently resulted in a degree of confusion. No-body knew exactly which name should be applied to the Moema sometimes imported from Peru. It is important to be aware that usually no informa-tion is available regarding the collecting sites of imported aquarium fish, so many reports on Moe-ma from Peru are still using incorrect names.

It has subsequently become clear that Moema ortegai and Moema quiii are one and the same species. In such cases the older name is the val-id one, in this case M. quiii. The fish sometimes termed M. cf. ortegai, which has been imported again recently, is in fact M. hellneri.

We are grateful to Steffen Hellner for providing the information above.

Reference:Costa, W. J. E. M. (2003): Two new annual fishes of the genus Moema Costa, 1989, from the Pe-ruvian Amazon (Teleostei, Cyprinodontiformes, Rivulidae). Boletim do Museu Nacional do Rio de Janeiro, Nova Série. Zoologia No. 513: 1-10.


Hence it is absolutely essential to research these animals before buying them. This arti-

cle will provide a number of hints, but even so a good handbook on the rearing and maintenance of European tortoises should figure on the book-shelves of every serious tortoise-keeper !

Which species?In the case of the beginner, only three species of European tortoises come into consideration:

Firstly, the Hermann’s Tortoise, Testudo hermanni, two subspecies of which are bred regularly. The eastern or ”common” Hermann’s Tortoise, T. h. boettgeri, which is very widespread in southern Europe (Bulgaria, Greece, Albania, Croatia, Bosnia and Herzegovina, Montenegro, Macedonia, Serbia, Romania, and parts of European Turkey) and the somewhat smaller western race T. h. hermanni (formerly robertmertensi), which is found only in parts of the western area of the species’ range (Spain, Italy, France). The Hermann’s Tortoise can be recognized by the horny “nail” on the end of the tail and by the marginal plate above the tail being divided centrally. Unlike T. h. boettgeri, T. h. hermanni has a yellow spot behind the eye and two parallel black bands on the ventral armor. The yellow spot is absent in T. h. boettgeri and there are large black spots on the ventral armor, but these do not merge to form bands. The eastern race grows to around 6-7 inches (15-18 cm) (males) and 7-10 inches (18-25 cm) (females) long, rarely with larger specimens, while the western race attains 4-6 inches (10-15 cm) (males) and 5.5-8 inches (14-20 cm) (females).

The proper way to keep young tortoises

The season for tortoises is here once again. The pet trade is full of the charm-ing little youngsters that hatched from their eggs during the summer. Anyone can keep these tortoises successfully. But only a few other animal species are subject to as many incorrect prejudices as tortoises. by Christoph Fritz, www.reptilia24.com

Juvenile Spur-Thighed Tortoise, Testudo graeca. All Photos: Frank Schäfer


http://www.reptilia24.com

The Vivarium - Issue 2 Vol. 342 Secondly, the Greek or Spur-Thighed Tortoise, Testudo graeca, with 14 subspecies, whose dis-tribution encompasses practically all the all coun-tries in Europe and Africa that border the Medi-terranean, and which also occurs in the Middle East (Iran, Iraq, Turkmenistan, Armenia, Geor-gia, Azerbaijan). To enumerate the differences between the subspecies here would be to go way too far, and in any case they usually cannot be detected in juveniles. It is sufficient to know that there are a very large number of subspecies, so that you don’t inadvertently produce a mish-mash when putting together breeding groups. The Spur-Thighed Tortoise has no horny nail on the end of the tail and the marginal plate above the tail is not divided. This species grows to 8-12 inches (20-30 cm) long.Thirdly, The Marginated Tortoise, Testudo mar-ginata, with an unknown number of subspecies. This tortoise was probably originally found only in Greece south of Mount Olympus, but even in an-cient times was introduced for food in many plac-es around the Mediterranean. Thus the popula-tion on Sardinia probably derives from such an introduction by the Romans. Whether the slightly deviant appearance of the Marginated Tortoise on Sardinia justifies the erection of a subspe-cies (T. m. sarda) is a subject much discussed and hotly debated among biologists. The same applies to the dwarf form of the Marginated Tor-toise, which has been described as the subspe-cies T. m. weissingeri. Some scientists accept this, others not. With a length of more than 14 inches (35 cm), the Marginated Tortoise is fundamentally the largest of the European species. Adult specimens are

The Marginated Tortoise (Testudo marginata) is the largest European tortoise species, exceptionally attaining 18 inches (45 cm) in length. Normally, however, it grows to only around 14 inches (35 cm) long.


difficult to mistake because of the typical form of the carapace - a narrowing of the carapace in the posterior third followed by the broad, projecting marginal plates. When it comes to the tail and the marginal plate above the tail, juveniles resemble the Spur-Thighed Tortoise, from which they can be distinguished by examining the underside: juvenile Marginated Tortoises have a striking

light and dark coloration to each of the ventral plates. In addition Marginated Tortoises lack the enlarged, spur-like scales always present on the thighs of the Spur-Thighed Tortoise.

The Horsfield or Russian Tortoise (Testudo hors-fieldi) is also frequently offered for sale, but is so specialized in its maintenance requirements that

Adult pair of Hermann’s Tortoises, Testudo hermanni boettgeri. The male (the individual on the left) was incor-rectly fed and kept in over-dry conditions when young, resulting in his humped carapace.

All the specimens in this photo are siblings that originated from the same clutch. Note that each specimen nevertheless exhibits individual markings and variations in the plates of the carapace. (Testudo hermanni, Hermann’s Tortoise).



we would prefer to devote a separate article of its own to it in a later issue of the News.

Different requirements?By and large it can be said that the first three spe-cies have similar requirements and can be kept under similar conditions. All three species can be found together in certain habitats in Greece! Hence the recommendations below apply equal-ly to the three species listed.

Babies live dangerouslyNewly-hatched tortoises are hardly ever seen in the wild. Why? Well, the little creatures with their still relatively soft armor are easy prey for numer-ous animals. Snakes capture them with ease; ev-ery fox, dog, or cat can eat them; they are a del-icacy for hedgehogs and other small carnivores; and danger also threatens from the air in the form of raptors and corvids. But once a tortoise reaches an age of around 10 years and begins to breed, then it lays on average 8-12 eggs year-round. An adult tortoise has hardly any enemies and can live to 80 years and even older in the wild. Hence it will produce around 700 eggs in the course of its life, and statistically speaking only two individuals need to grow to adulthood in order to maintain the population. From this it can be seen that the mortality rate among juveniles in the wild is immense and well over 90% of the offspring perish when still young. In order for any youngsters to survive at all they need to stay very much in hiding, and that is precisely what they do. Which explains why small youngsters are practically never encountered in the wild. So what does this mean when it comes to terrarium maintenance? Quite simply, the terrarium, be it in the house or outside, must be arranged with numerous hiding-places so that the little ones can feel secure. These hiding-places must also be easy for the owner to monitor, as otherwise he will lose control over what is going on. Cork bark is best suited to the purpose, as it is relatively light and so presents virtually no risk of injury to the young tortoises if the pieces are lifted every day for checking and then put back in place. If the tortoises are forced into a permanently visible existence then the more sensitive specimens among them will be subject to such long-term stress that sooner or later disease will set in, perhaps with fatal results. So, always provide hiding-places! If the tortoises don’t use them then they can always be removed, but first make absolutely sure that the hiding-places aren’t

Adult specimen of Testudo graeca ibera of unknown provenance.

Identification characters of European tortoises. From top to bottom: Testudo graeca, T. hermanni, and T. marginata.


being avoided for reasons such as too hot or cold, too dry or wet, too difficult to get into, etc.

Not too dry!Their secretive way of life also explains why baby tortoises are adapted to a higher degree of moisture in their environment than are adult individuals, which are often found in bone-dry areas. It is always somewhat damper in holes, beneath stones, and so forth than in the open countryside. If young European tortoises are kept in too dry an environment then the result may be unnatural deformations of the carapace, especially the dreaded pyramiding development. Ideally they should be maintained on a relatively deep, loose, substrate comprising a mixture of one part each of sand, earth, and humus. This substrate should be about 4 inches (10 cm) deep and set with a number of shrubby plants: indoors the ideal is small palms (for example Chamaerops humilis), as they are very robust and can’t be trampled down even by larger tortoises, while outside shrubby cinquefoils (for example Potentilla fruticosa), thymes, or lavenders can be used. If the watering is such that the plants grow well (ie no drying out or flooding) then the moisture level will always be correct for the tortoises as well.

Feed sparingly!The second mistake that is repeatedly made is to feed much too much of a far too lush diet. Young European tortoises should be given exclusively grasses and greens (including lettuce, hay, etc.), but never fruit, vegetables, meaty foods, soaked bread, or the like. The tortoises may well eat all this with enjoyment, but it is extremely unhealthy for them. Nature is parsimonious in the natural habitat! They are unable to travel far for food in the wild as they wouldn’t survive

Baby T. graeca ”East Anatolian Giant”. Baby Testudo graeca anamurensis.

Baby Testudo graeca terrestris.

Baby Testudo graeca ibera.

such wanderings. So they search for food in the relatively limited area around their hiding-places, and there won’t be all that much there. Food too rich in calories is undoubtedly the commonest cause of death in young tortoises in captivity. In practice this means that unlimited amounts of dry, nutrient-poor, but roughage-rich food such as hay and hay pellets should always be available. In addition you can give a handful of mixed fresh food (plantains, dandelions, clover, grasses, etc) per individual per day or, if nothing is available from the meadows, salad leaves such as Rocket, Romaine lettuce, Endive, or Lamb’s Lettuce. Iceberg and cabbage lettuce should be avoided, they aren’t particularly healthy.

Lots of light!Light is of immense importance for keeping Eu-ropean tortoises healthy. Here too well-planned planting can be very helpful: if the plants listed above are growing well then there is also suffi-

cient light and its composition is suitable for the tortoises. UV light is of particular importance. As in us humans, Vitamin D3, which is of great importance in bone metabolism, is synthesized in the skin of reptiles under the influence of UV light. Softening of the bones (best seen in the shell, which is, after all, composed of bone) can be the result of too little UV light. The trade offers a huge selection of UV-light sources, providing something suitable for every need. But be aware that UV light alone cannot replace the amount of full-spectrum light required! The amount of full-spectrum light has a huge effect on the cal-cium uptake of tortoises; without adequate light they will certainly fall ill.

Singly or in groups?European tortoises are essentially solitary in the wild and come together only to mate and in re-sponse to particular triggers (overwintering; lo-cal, seasonal reductions in food supply). They

Female Hermann’s Tortoise T. h. boettgeri from the Zadar area (Croatia).


do not become imprinted on humans and even a newly-hatched baby tortoise knows instinctively that it is a tortoise, as it will never have known its mother or another adult tortoise in the wild. European tortoises always become tame, ie they learn to recognize humans as a source of food and react to them accordingly. All this is indepen-dent of whether they are kept singly or in groups.

The advantage of group maintenance is that in-dividuals kept in groups experience more social stress, which has a positive effect on their health. Unlike in everyday usage where the word “stress” always has negative connotations, scientists draw a very clear distinction between negative stress (the technical term is “distress”) and pos-itive stress (“eustress”). Either can cause illness if it outweighs the other to a significant degree. Too much peace and quiet can be just as harmful as too much excitement. A balanced mixture is ideal.

Adult female and juveniles of T. h. hermanni from the area around Rome (Italy).

Adult T. graeca ibera from Turkey.



Many animals experience too little negative stress in captivity, as predation pressure is lack-ing, and likewise the harmful environmental in-fluences that cost very many lives in the wild are largely absent. In addition parasite pressure is very much lower in captivity than in the wild. So in terms of maintaining good health the negative stress resulting from social stress (ie compe-tition for food, squabbling over the best hiding- and sunbathing-places, etc) is very beneficial and hence group maintenance is preferable to keeping them singly. In addition it will provide the owner with numerous opportunities for interest-ing observations on the social interactions of the tortoises.

As mentioned at the beginning, an article like this cannot and should not try to be a substitute for a comprehensive handbook. It is intended to provide advice on the commonest causes of mis-takes in the maintenance of baby tortoises and how to avoid them. Major and important topics such as “outdoor or terrarium maintenance”, “ter-rarium and pen size”, and “over-wintering” have been deliberately omitted, as they are beyond the scope of an article like this. They will instead be discussed in another issue of the Vivarium.

Baby Marginated Tortoise, Testudo marginata. All Photos: Frank Schäfer


We hope you enjoyed

this issue of

© Text & Photos:Frank Schäfer / Aqualog

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the vivarium - issue 3 / volume 2

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