the tasm anian m udfish, galaxias cleaveri · galaxias, galaxias brevipinnis g unther, and the m...

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THE TASMANIAN MUDFISH, GALAXIAS CLEAVERI SCOTT, 1934, IN VICTORIA J. D. Koehn and T. A. Raadik Freshwater Ecology Branch, Department of Conservation and Environment, 123 Brown Street, Heidelberg, Victoria 3084 K o e h n , J. D. & R a a d ik , T. A., 1991:12:31. The Tasmanian mudfish, Galaxias cleaveri Scott, 1934, in Victoria. Proceedings of the Royal Society of Victoria 103 (2): 77-86. ISSN 0035-9211. Galaxias cleaveri Scott, 1934 is recorded for the first time from the Aire River basin in western Victoria, extending the known westerly distribution of the species. The habitat, general biology and behaviour of the species are described and comparisons made with three species of New Zealand mudfish ( Neochanna spp.). G. cleaveri is nocturnal and able to survive periods without free surface water. Large areas of potential G. cleaveri habitat have been destroyed in Victoria, and the preservation of freshwater wetland habitats is essential to the survival of the species in this State, where a conservation status of vulnerable remains justified. THE TASMANIAN MUDFISH, Galaxias cleaveri Scott, a member of the southern hemi- sphere family Galaxiidae, is a scaleless salmoni- form fish first described from Tasmania in 1934 although specimens had been dug up at Strahan in western Tasmania in 1900 (Hall 1901, Scott 1934). The species was considered endemic to Tasmania until 1980 when specimens were discovered on mainland Australia (Jackson & Davies 1982). In the 56 years since its discovery G. cleaveri has been recorded only spasmodi- cally, an indication that it is rare in terms of distribution and abundance. Consequently little is known of the general biology and ecology of this species; indeed, not until 1986 did anyone report that it possesses a marine larval stage (Fulton 1986). In the present paper we highlight the presence of G. cleaveri in Victoria and pro- vide updated information to help further work and the development of management strat- egies. Detailed descriptions of G. cleaveri were given by Andrews (1976), McDowall & Frankenberg (1981) and Cadwallader & Backhouse (1983), and the last authors provided a colour photo- graph. Even so, workers less skilled in the tax- onomy of fish may experience difficulty in distinguishing G. cleaveri from the broad-finned galaxias, Galaxias brevipinnis Gunther, and the mountain galaxias, Galaxias olidus Gunther, which may occur within the same river system. The following morphological features may be used as a simplified guide to distinguishing adult G. cleaveri from G. brevipinnis and G. olidus (Fig. 1). 1. Anal fin slightly behind origin of dorsal fin in G. cleaveri. 2. Shape of dorsal and anal fins: low, rounded to ovoid, elongated posteriorly in G. cleaveri. 3. Shape of caudal fin: rounded to truncated in G. cleaveri. 4. Shape of flanges on caudal peduncle: large, long and raised in G. cleaveri. 5. Shape of pectoral fins: large and rounded in G. cleaveri. 6. Small head in G. cleaveri. 1. Size of eyes: small in G. cleaveri. 8. Large long tubular nostrils: more pronounced in G. cleaveri. Morphological similarities are exhibited with three species of New Zealand mudfish (McDowall & Whitaker 1975, McDowall 1990): the Canterbury mudfish, Neochanna burrowsius (Phillipps) (Skrzynski 1968, Cadwallader 1975); the brown mudfish, N. apoda Gunther (Eldon 1968, 1971); and the black mudfish, N. diversus Stokell (Thompson 1987, McDowall 1990). In habitat and habits G. cleaveri shows similarities to these species and to the dwarf galaxias, Gal- axiella pusilla (Mack) (Backhouse & Vanner 1978, Beck 1985, Humphries 1986). DISTRIBUTION Previous records G. cleaveri has been found to be patchily distri- buted in coastal areas in the north, south and west of Tasmania (Andrews 1976, McDowall & Frankenberg 1981, Fulton 1990) but was re- ported to be absent from Flinders and King

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Page 1: THE TASM ANIAN M UDFISH, GALAXIAS CLEAVERI · galaxias, Galaxias brevipinnis G unther, and the m ountain galaxias, Galaxias olidus G unther, which may occur within the same river

TH E T A SM A N IA N M U D F ISH , GALAXIAS CLEAVERI SCOTT, 1934, IN VICTORIA

J. D . K o e h n a n d T. A. R a a d i k

Freshw ater E cology Branch, D epartm en t o f C onservation and E nv ironm en t,123 Brown Street, H eidelberg, V ictor ia 3084

K o e h n , J. D . & R a a d i k , T. A ., 1991:12:31. T he T asm an ian m udfish, G a la x ia s c leaver iScott, 1934, in V ictor ia . P ro ceed in gs o f the R o y a l S o c ie ty o f V icto r ia 103 (2): 7 7 -8 6 .ISSN 0035 -9211 .G a la x ia s c leaver i Scott, 1934 is recorded for the first t im e from the A ire R iver basin in

w estern V ictoria, ex tend ing the know n w esterly d istr ibu tion o f the species. T he habitat, general b io logy and behav iou r o f the species are described and com parisons m ade w ith three species o f N ew Zealand m udfish (N eoch an na spp.). G. c leaveri is nocturnal and able to surv ive per iods w ithou t free surface water. Large areas o f poten tia l G. c leaveri habitat have been destroyed in V ictor ia , and the preservation o f freshwater w etland hab itats is essen tia l to the surviva l o f the species in th is State, w here a conservation status o f vu lnerable rem ains justif ied .

T H E TA SM A N IA N M U D F IS H , Galaxias cleaveri Scott, a m em ber o f the sou thern hem i­sphere fam ily G alax iidae, is a scaleless salm oni- form fish first described from T asm an ia in 1934 although specim ens had been dug up a t S trahan in w estern T asm an ia in 1900 (H all 1901, Scott 1934). T he species w as considered endem ic to T asm an ia un til 1980 w hen specim ens were d iscovered on m ain land A ustra lia (Jackson & D av ies 1982). In the 56 years since its d iscovery G. cleaveri has been recorded only spasm od i­cally, an ind ica tion th a t it is rare in term s o f d is tr ibu tion and abundance. C onsequently little is know n o f the general biology and ecology o f th is species; indeed, no t un til 1986 d id anyone repo rt th a t it possesses a m arine larval stage (F u lton 1986). In the p resen t paper we h ighlight the p resence o f G. cleaveri in V ic to ria and p ro ­v ide updated in fo rm ation to help fu rthe r w ork and the deve lopm ent o f m anagem ent s tra t­egies.

D eta iled descrip tions o f G. cleaveri w ere given by A ndrew s (1976), M cD ow all & F rankenberg(1981) and C adw allader & B ackhouse (1983), and the last au tho rs p rov ided a co lour p h o to ­graph. Even so, w orkers less skilled in the tax ­onom y o f fish m ay experience difficulty in d istingu ish ing G. cleaveri from the broad-finned galaxias, Galaxias brevipinnis G un ther, and the m ou n ta in galaxias, Galaxias olidus G un ther, w hich m ay occur w ith in the sam e river system .

T he follow ing m orpho log ical features m ay be used as a sim plified guide to d istingu ish ing adu lt G. cleaveri from G. brevipinnis and G. olidus (Fig. 1).

1. A nal fin slightly b eh ind orig in o f dorsal fin in G. cleaveri.

2. Shape o f dorsal and anal fins: low, rounded to ovoid, elongated posterio rly in G. cleaveri.

3. Shape o f caudal fin: rounded to tru n ca ted in G. cleaveri.

4. Shape o f flanges on caudal peduncle: large, long and ra ised in G. cleaveri.

5. Shape o f pecto ra l fins: large and rounded in G. cleaveri.

6 . Sm all head in G. cleaveri.1. Size o f eyes: sm all in G. cleaveri.8. Large long tub u la r nostrils: m ore p ronounced

in G. cleaveri.M orphological s im ilarities are exh ib ited w ith

th ree species o f N ew Z ealand m udfish (M cD ow all & W h itaker 1975, M cD ow all 1990): the C an terbury m udfish, Neochanna burrowsius (Ph illipps) (Skrzynski 1968, C adw allader 1975); the brow n m udfish, N. apoda G u n th e r (E ldon 1968, 1971); and the b lack m udfish, N. diversus Stokell (T hom pson 1987, M cD ow all 1990). In h ab ita t and hab its G. cleaveri shows sim ilarities to these species and to the dw arf galaxias, Gal- axiella pusilla (M ack) (B ackhouse & V anner 1978, Beck 1985, H um phries 1986).

D IS T R IB U T IO N

Previous records

G. cleaveri has been found to be patch ily d is tr i­bu ted in coastal areas in the no rth , sou th and west o f T asm an ia (A ndrew s 1976, M cD ow all & F rankenberg 1981, Fu lton 1990) bu t was re­po rted to be absent from F linders and K ing

Page 2: THE TASM ANIAN M UDFISH, GALAXIAS CLEAVERI · galaxias, Galaxias brevipinnis G unther, and the m ountain galaxias, Galaxias olidus G unther, which may occur within the same river

• 'zZrcJiL..' -^ '“V -.T's-

; *r. . . .---- ' sX’ •;^ C t\<2 t - .- t ' 1\

■ M., -1

F igu re 1. M orphological features d istinguish ing G a la x ia s c leaver i (B) from G. o lid u s (A) and G b rev in in n h (C \ (A fter M cD ow all & Frankenberg 1981.) e v ip in m s yC).

Islands in the 1960s (F rankenberg 1967). A ndrew s (1976) was surprised at the absence o f G. cleaveri from the Bass S trait islands and m ain land A ustralia, even though at th a t tim e he d id no t know th a t the species possessed a m arine juven ile stage.

G. cleaveri was first recorded on m ain land A ustra lia in 1980 from the south-east side o f W ilsons P rom onto ry , V icto ria (Jackson & D av ies 1982). In 1983 ano ther ind iv idua l was recorded from the low er reaches o f the W ye R iver, O tw ay Ranges (K oehn & O ’C onnor 1990a; specim en N M Y A7594, D epartm en t o f Ichthyology, M useum o f V ictoria, M elbourne), ex tend ing the know n range o f the species in to w estern V ictoria. These tw o sites are referred to herein as sites 1 and 2 (Fig. 2, Tab le 1).

Subsequently , G reen (1984) repo rted G cleav- eri from a d ra in on F linders Island, Bass S tra it (specim ens Q V M 1984/5/6, Q ueen V ic to ria

A rt G aller>’’ L aunceston , and N M V A3391). T h is record com p leted a d istr i- bu tion pa tte rn co incid ing w ith th a t o f o th e r galaxnd species hav ing a trans-B assian d is tr i­bu tion nam ely G. brevipinnis, G. maculatus (Jenyns), G. truttaceus (V alenciennes) an d Gal- axiella pusilla (F rankenberg 1967).

It is no t surprising th a t G. cleaveri has been recorded in only tw o o f the num erous o th e r su r­veys prev iously conducted to determ ine the d is­tr ib u tio n o f freshw ater fish in coasta l V ic to ria (see K oehn 1990, K oehn & O ’C onno r 1990a K oehn et al. 1991). Sites sam pled during those surveys were m ostly in stream s ra th e r th an in

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F igu re 2. L oca lities from w h ich G a la x ia s c leaveri has been recorded in V ictor ia (□ ); • = add itiona l sites surveyed in th is study, but w here G. c leaver i w as not found . Inset: areas w here G. c leaveri w as p rev iously recorded by Jackson & D av ies (1982) (1) and K oehn & O ’C onnor (1990a) (2).

sw am p and d ra in hab ita ts favoured by th is spe­cies. In add ition , specim ens o f G. cleaveri m ay have been m isidentified , particu larly before the species was recognised as occurring in V ic­to ria.

New records

In 1990 we surveyed likely G, cleaveri hab ita ts (sm all creeks, d ra ins and sw am ps) in the low land coastal p la ins o f the O tw ay R anges betw een Skenes C reek (143°43'E, 38°43'S) and the Jo h an n a R iver (143°23'E , 38°45'S) (Fig. 2). T w enty-four sites w ere sam pled using a Sm ith R oo t M odel 12 backpack electrofisher and d ip nets. D eta ils o f all sites sam pled and fish species collected are inc luded in K oehn et al. (1991). E leven specim ens o f G. cleaveri w ere collected from th ree sites (sites 3 ,4 and 5; Fig. 2 and Table 1) in the A ire and C alder R iver valleys, 35 km w est o f the locality on the W ye R iver w here the species was recorded by K oehn & O ’C onnor

(1990a). Specim ens have been deposited w ith the M useum o f V ictoria: N M V A 9512 (C alder R iver); N M V A 9513, A 9 5 10 (A ire R iver, drain); N M V A 9 5 1 1 (A ire R iver, b illabong).

P opu la tion density o f G. cleaveri a t the th ree sites could no t be estim ated because o f the dense vegetation and because o f the cryp tic and noc­tu rna l hab its o f G. cleaveri. T he op tion o f c lear­ing aquatic vegetation to sam ple m ore effec­tively was re jected as all sites w ere sm all in area.

Associations

All o ther species associated w ith G. cleaveri (Table 1) are com m on in the area (K oehn & O ’C onnor 1990a), are d iad rom ous (w ith the ex­cep tion o f Pseudogobius olorum), an d m ost have been recorded from low-lying sw am py hab ita ts . P. olorum is usually residen t in low er freshw ater o r estuarine areas as well as in coasta l lagoons (A llen 1989), and the specim ens o f G. brevipin-

Page 4: THE TASM ANIAN M UDFISH, GALAXIAS CLEAVERI · galaxias, Galaxias brevipinnis G unther, and the m ountain galaxias, Galaxias olidus G unther, which may occur within the same river

SiteN o. W aterway

M ap N o . & Grid Ref.

A ltitude(m )

D ateSam pled

N o.C ollected

T ota l Length

R ange (m m ) A ssoc. Species

1 Freshw ater CreekA 8119 493746 20 29 .1 0 .8 0 5 37 -75* Sfeel,C gal

(tributary) 16.12 .80 102 W ye R iverB 7620 514196 10 ' 14.09.83 1 93* A m m ,C gal,A grayl,

T up ,B tr3 ■ C alder R iver (drain) 7620 178056 20 17.10.90 1 90 Sfeel,C gal4 A ire R iver (drain) 7520 147063 10 31 .05 .90 2 5 6 -5 7 Sfeel, Cgal

24 .08 .90 5 7 4 -9 6 Sgal,Bgal,Bsg -

17 .10 .90 2 8 5 -9 0 —

5 A ire R (b illabong) 7520 151068 15 16.10 .90 1 80 —

am m = lam prey am m ocoetes, G eo tr ia a u stra lis or M o rd a c ia m o rd a xCgal = com m on galaxias, G a la x ia s m a cu la tu sSfeel = short-finned eel, A n g u il la au stra lisSgal = spotted galaxias, G a la x ia s tru tta ceu sB g a l = broa d-fin ned g a la x ia s, G a la x ia s brev ip in n isT up = tupong, P seu d a p h r itis u rv illi iBtr = brow n trout, S a lm o tru ttaAgrayl = A ustralian grayling, P ro to tro c tes m a ra en aBsg = b lue-spot goby, P seu dogob iu s o lo rum

A from Jackson & D av ies (1982)B from K oehn & O ’C onnor (1990a)* standard lengths

T a b le 1. Sum m ary o f site and co llection details for G a la x ia s c leaveri in V ictoria.

nis co llected w ere juven iles m igrating upstream to adu lt hab ita t.

T he association o f eels and o ther species o f galax iids w ith N ew Z ealand m udfish (Neo- channa spp.) has been observed by E ldon (1968), and G. cleaveri has been associated w ith o ther galax iids and w ith sou thern pygm y perch, Nan- noperca australis G u n th er (Scott 1936, 1971).

In G. cleaveri hab ita ts surveyed on m ain land A ustra lia the o th er residen t galax iid species are essentially free-sw im m ing, w hereas G. cleaveri is ben th ic. T hus G. cleaveri m ay face na tu ra l in terspecific com petition o r p red a tio n only from eels w hich are also ben th ic and m ay occupy sim ilar hab ita ts.

Biogeography

T he d is tr ibu tion o f freshw ater na tive fishes in the O tw ay region appears to be p rim arily re lated to geom orphological cond itions th a t ex isted during and after the last g laciation 5 ,000-20 ,000 years ago (K oehn & O ’C onnor 1990a). Such con­d itions restr ic ted non -d iad rom ous freshw ater species to the larger B arw on R iver system to the no rth and to the A ire and G ellib rand R iver system s to the south-w est, w hereas only d iadro- m ous species inhab it the short coastal stream s.

T he d iad rom ous lifecycle o f G. cleaveri accoun ts for its occurrence in the W ye R iver.

F rankenberg (1974) suggested th a t G. trutta­ceus and G. brevipinnis, bo th species w ith life­cycles sim ilar to th a t o f G. cleaveri, m ay have m igrated to m a in land A ustra lia from T asm an ia w hen a land bridge ex isted du ring th e P le is to ­cene glaciation. A sim ilar m ig ra tion m ay be sug­gested for G. cleaveri. F u lton (1986) described a re tu rn to fresh w ater by ju v en ile G. cleaveri and suggested a m arine phase in the species’ lifecycle (F u lton 1990). T he d is tr ib u tio n and residency o f the larval phase o f G. cleaveri is unknow n, as is the possib ility o f land-locked po p u la tio n s o f the species no t possessing a m arine life phase. Such popu la tions are know n in o th er no rm ally d iad rom ous galax iid species (P o llard 1972 H um phries 1989, F u lton 1990, M cD ow all 1990).

T he p resent d is tr ibu tion o f G. cleaveri closely conform s to the region encom passed by the land bridge (W ilsons P rom on to ry to C ape O tw ay). L arvae develop ing in m arine w aters w ou ld be d ispersed m ore w idely and the species w ou ld be expected to be m ore w idely d is tr ibu ted . T he oc­currence o f larval galax iids as far as 700 km from the coast o f N ew Z ea land supports the theo ry o f M cD ow all (1978) th a t long-range d ispersa l o f

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d iad rom ous species m ay occur, as is exh ib ited by G. truttaceus and G. brevipinnis w h ich are w idespread in V ic to rian coasta l s tream s (K oehn & O ’C onno r 1990a, 1990c). T he m ore restr ic ted d is tr ib u tio n o f G. cleaveri suggests th a t the larvae m ay be confined to estuaries, although

- fu rthe r surveys are needed to e luc idate d ispersal m echan ism s.

H A B ITA T

A com prehensive descrip tion o f the und istu rbed h ab ita t a t site 1 was g iven by Jackson & D av ies(1982). S ite 2 w hich is also u n d is tu rb ed is a sm all steep stream w ith a poo l-riff le sequence d ra in ­ing m oun ta inous fo rest country . T he substrate consisted o f cobbles and gravel, the flow was high, fast and tu rb id , the conductiv ity was 150 EC and w ater tem p era tu re w as 10°C. I t is poss­ib le th a t the specim en found a t th is site had been w ashed from areas o f low-lying pastu re during recent ra ins.

All new sites w ere characterised as being m odified w ith all r ip a r ian vegetation rem oved, and sites 3 and 4 had also been channelized.

Site 3 is a shallow channel (1 m w ide, 0.2 m deep) w ith a 0.8 m m ud substra te and w ith w ater 2 0 -3 0 m m deep d ra in ing from a spring in a pas­tu red paddock in to the C alder R iver. A t the tim e o f co llection (17 O ctober 1990) the channel had recently been excavated and little vegetation was presen t. D isso lved oxygen concen tra tions were 5.7 m g/L , pH was 7.0 and conductiv ity was 680 EC at 8.0°C. O n 27 F ebruary 1991 the d ra in was heav ily vegetated w ith a varie ty o f native and in troduced species o f aqua tic and pastu re veg­e ta tion , the w ater was 2 0 -3 0 m m deep, and the m ud substra te was 2 0 0 -4 0 0 m m th ick.

S ite 4 is a shallow d ra in (0 .2 -0 .4 m deep) w ith a silt substra te lead ing from a spring in a cleared paddock in to the A ire R iver. O n 24 A ugust 1990 m ost o f the site consisted o f a 2 m w ide channel together w ith a larger 15 m x 20 m area, and was densely vegetated w ith aqua tic species. C onduc­tiv ity was 185 EC a t 10°C. O n 17 O ctober 1990 d isso lved oxygen concen tra tion was 5.6 mg/L, pH was 6.7, and conductiv ity was 850 EC at 17°C. O n 27 F eb ruary 1991 there w as 100 m m o f m ud and a little w ater up to 20 m m deep in cattle h o o f p r in ts in the channel. T he larger area had sh runk to 3 m x 20 m w ith up to 100 m m o f w ater and 300 m m o f m ud. Sections o f the d ra in o ften becom e dry during sum m er bu t o ther sections always rem a in m o ist due to an underg round spr­ing (D . D enney pers. com m .).

S ite 5 is a sm all b illabong (60 m x 5 m x 0.8 m deep) abou t 30 m from the A ire R iver. N o flow was apparen t and the substra te was silt w ith dense aqua tic vegetation. O n 16 O ctober 1990 the w ater was dark tan n in in co lou r and h ad a d isso lved oxygen concen tra tion o f 4 .0 m g/L , pH o f 6.4 and conductiv ity o f 190 EC at 16.5°C. O ne specim en o f G. cleaveri was co llected from ju s t inside a large log ly ing in the w ater. O n 27 F e­bruary 1991 the site was com pletely dry, a con ­d ition no t unusual fo r th is season (D . D enney pers. com m .).

All sites are at low a ltitudes (a m ax im um o f 20 m above sea level) and close to the sea (a m ax i­m um o f 8.5 km from the sea bu t only 3 km from brack ish w ater). Except fo r site 2, all sites h ad no d iscern ib le flow and had m ud o r silt substrates and dense aqua tic vegetation. A lthough A ndrew s (1976) considered th a t G. cleaveri to l­era ted brack ish w ater, all ou r specim ens w ere collected from fresh w ater. T he d ra in lead ing from site 3, how ever, flowed in to reaches o f the A ire R iver w hich are know n regularly to con ta in an estuarine salt-wedge u n d er low flow con­d itions (J. K oehn pers. obs.).

T he presence o f G. cleaveri a t these sites is consisten t w ith its occurrence elsew here in sw am ps, d ra ins and sem i-perm anen t w aters. G. cleaveri was collected from stagnan t poo ls in T asm an ia (A ndrew s 1976) and from a d ra inage system usually dry in sum m er on F linders Island (G reen 1984). F u lton (1986) also recorded G. cleaveri from a dry section o f the E sperance R iver in T asm an ia. In N ew Z ealand th ree species o f m udfish, Neochanna burrowsius, N. apoda and N. diversus, have also been described as specialised to life in sw am ps, creeks and d ra ins th a t tend to dry up in sum m er (E ldon 1968, 1978, 1979a, M cD ow all 1990).

Scott (1934) described G. cleaveri as one o f the m ost specialised galaxiids in hav ing adop ted a m ode o f life su ited to such hab ita ts. Such ad ap ­ta tio n and an association w ith low a ltitude, sw am py hab ita ts is likely to ind icate a high de­gree o f dependance on the p resence o f ap p ro p ri­ate hab ita ts. C ollection o f the species in V ic to ria from d isjunct and highly m odified areas con­ta in ing in troduced vegetation suggests th a t these popu la tions m ay be rem nan ts o f a larger p o p u ­la tion th a t once existed w hen su itab le hab ita ts were m ore w idespread.

B EH A V IO U R

W e kep t fou r G. cleaveri from site 3 in a glass aquarium (0.36 x 0.45 x 0 .10 m ) con ta in ing a silt

Page 6: THE TASM ANIAN M UDFISH, GALAXIAS CLEAVERI · galaxias, Galaxias brevipinnis G unther, and the m ountain galaxias, Galaxias olidus G unther, which may occur within the same river

substra te and vegetation from the site. T he be­h av iou r and position o f the fish were observed at in terva ls th roughou t each day for th ree weeks, and a t 5 m inu te in tervals fo r 1 hou r during one night.

G enerally the fish w ere inactive during the day, resting e ither on the substrate o r am ongst vegetation, and were difficult to locate because o f th e ir co lour and cryptic hab it. Ind iv iduals spent tim e resting e ither on the substrate w herever cover was available, o r am ongst dense w eed ju s t below the w ater surface. In bo th s itu ­ations, several ind iv idua ls shared the sam e cover and were in physical con tact w ith each other. T h is behav iou r is s im ilar to th a t described by E ldon (1969) in Neochanna apoda w hich is also te rr ito r ia l and aggressive to o ther species in aquaria (E ldon 1968). Ind iv iduals o f G. cleaveri exh ib ited no such aggressive behav iou r to each o ther o r to ind iv idua ls o f Galaxias maculatus o r G. truttaceus w hich were p laced in to the aquaria a t d ifferent tim es. A t n ight G. cleaveri were m ore active, continually m ov ing around open areas “ brow sing” . A t least tw o o f the fish were in open areas a t each observation . They im m ediate ly re­trea ted in to the vegetation w hen exposed to e ither w hite o r red light bu t had always re­appeared in the unvegetated areas by the next observation .

O ur observations ind icate th a t G. cleaveri is a noctu rna l, cryptic species w hich often inhab its the aqua tic vegetation ra th e r th an the substrate. O ther species o f galaxiids repo rted to be noctu r­nal are Neochanna apoda (E ldon 1968), Gal­axias brevipinnis (G lova & Sagar 1989a), and Galaxias vulgaris Stokell (G lova & Sagar 1989b).

A ESTIV A TIO N

Scott (1934) gave details o f the ability o f G. cleaveri to aestivate, though u nder unnatu ra l cond itions. T h is ab ility has been no ted by sev­eral o ther au thors (F letcher 1907, H all 1901, F u lton 1986) though the ir descrip tions m ain ly concern recovery o f aestivating ind iv iduals. Fu l­ton (1986) p rov ided pho tograph ic ev idence o f G. cleaveri aestivating during m id -sum m er u n d er a rock at least 10 m from free w ater.

M cD ow all & Pusey (1983) repo rted aestiv ­a tion in Lepidogalaxias salamandroides, and aestivation o f Galaxiella pusilla was suggested by M cD ow all & F rankenberg (1981). H u m p h ­ries (1985) tested th is suggestion by m ain ta in ing specim ens o f G. pusilla in an aquarium for 36 days w hilst low ering w ater levels and m a in ta in ­

ing oxygen concen tra tions a t less th an 5 ppm . F ish surv ived on the surface o f the m ud an d in a sm all hole for several days in the absence o f surface w ater. M cD ow all (1990) p resen ted ev i­dence o f the ab ility o f the N ew Z ea land m u d ­fishes Neochanna burrowsius an d N. apoda to surv ive dry periods, though bo th E ldon (1978) and M ered ith (1985) conc luded th a t these spe­cies do no t exh ib it true aestiva tion du ring w hich the ind iv idua l becom es to rp id and the no rm al ra te o f m etabo lism decreases.

W e investigated w hether bu rrow ing an d aesti­vation could be induced in G. cleaveri by p lacing tw o ind iv idua ls (101 m m and 78 m m TL ) in to a glass aquarium (0.3 x 0.62 x 0.3 m ) con ta in ing a substrate o f soil and m ud, a large flat rock a t one end, dense aquatic vegetation in the m idd le , and a p iece o f log at the o ther end. T he w ater level was low ered artificially, and heating an d il lum i­nation w ere p rov ided during the day by an incandescent globe. O n day 10 som e tunnelling in the m idd le section o f the tan k was observed, and one fish was seen lying near the w ate r su r­face w here it spasm odically gu lped w ate r an d air. O n day 14, w hen the w ater level h ad fa llen to10 m m above the substrate, one fish was resting in a vertical shaft in the m ud w ith its head ju s t p ro trud ing . O n day 22 n e ith e r fish cou ld be seen and no surface w ater rem ained , though w ater was p resen t in the open ing o f the shaft. L a te r on the sam e day the heads o f bo th fish w ere pos­itioned in the shaft open ing and th e ir bod ies were u n d er the m ud in h o rizon ta l tunnels. O n day 25 a series o f sm aller open ings w ere ob ­served in a line d irec ted aw ay from th e large shaft, p resum ab ly along the h o rizo n ta l tunne ls. O n day 31 there was no w ater in the p it o f the large shaft, the m ud substra te h ad begun to dry, and one G. cleaveri h ad its head p ro tru d in g from the tunne l in to the shaft below the surface o f the substrate. O n day 32, a fte r 5 days w ithou t any free w ater, the fish in the tunne ls stopped m ov ­ing. O n day 42 w hen the substra te h ad d ried to only 30 m m th ick the tw o G. cleaveri w ere seen th rough cracks in the dry m ud ly ing in th e tu n ­nels. T he tank was then slowly rehyd ra ted , and the fish recovered m ovem en t and em erged w hen the m ud becam e soft. T hey bo th im m ed ia te ly fed on earthw orm s and show ed no ill effects from surv iv ing in stagnan t w ater fo r 14 days and w ithou t surface w ater fo r an o th e r 14 days.

W hilst no t physio logically confirm ing the ab ility o f G. cleaveri to aestivate, o u r study shows th a t the species can su rv ive perio d s w ithou t free surface w ater by burrow ing in to the substrate.

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L IFE C Y C L E

Two m ale G. cleaveri co llected a t site 4 on 31 M ay 1990 w ere in a r ipe spaw ning stage (Po llard 1972), w hereas ind iv idua ls co llected on 24 A u­gust 1990 w ere all spen t o r undeve loped , in d i­cating a w in ter spaw ning. T hese observations are consisten t w ith those o f A ndrew s (1976) w ho reported fully developed eggs in a specim en o f G. cleaveri exam ined in T asm an ia du ring M ay. A fter ageing w h iteba it re tu rn in g to freshw ater as approx im ate ly 2 m on ths o ld, F u lto n (1986) sug­gested th a t G. cleaveri spaw n du ring m id-w in ter, and he believes (W. F u lto n pers. com m .) th a t juven ile G. cleaveri re tu rn to fresh w ater during spring along w ith o th er galaxiids.

C adw allader (1975) and E ldon (1979a) con ­cluded th a t Neochanna burrowsius in N ew Z ea­land spaw ns during la te w in ter and early spring in hab ita ts frequen ted by adu lts. In con trast, E ldon (1979a) suggested th a t N. apoda spaw ns during m ost m on ths o f the year, especially w hen a drought breaks. B ecause E ldon (1971) found th a t in an aquarium N. apoda deposited eggs above the w aterline, he specu la ted th a t in the w ild the species deposits eggs ou t o f the w ater am ongst dam p vegetation and detritus. T he spaw ning location o f G. cleaveri has no t yet been found.

P resen t ev idence ind icates th a t G. cleaveri is un ique am ongst galax iids in possessing the tw o characteristics o f aestiva tion and d iadrom y.

TH R EA TS A N D C O N SE R V A T IO N STA TU S

G eneral th rea ts to freshw ater native fish in V ic to ria have been described by K oehn & O ’C onno r (1990b) w ho considered h ab ita t re­m oval and a lte ra tion a p rim e reason fo r the decline o f m any species. T he re liance o f G. cleav­eri on specific h ab ita t w ould app ear to m ake it susceptib le to h ab ita t changes, particu larly the loss o f w etland hab ita t.

T he m ain tenance o f fish hab ita ts has been rec­ognised as a key issue in m anagem ent o f the S tate ’s freshw ater fish fauna (K oehn & O ’C on­n o r 1990c). W hilst up to one-th ird o f the S ta te ’s w etlands have been destroyed (D C E 1988), m ost o f the assessm ents have re la ted only to w ater- b irds; fu rth e r assessm ents in re la tion to changes to fish hab ita ts are necessary. C orrick (1981, 1982) and C orrick & N o rm an (1980) assessed coastal w etlands in sou thern V ic to ria and as­signed them to the fo llow ing categories.1. F looded r iv e r flats: land in u n d a ted fo r very

sho rt periods fo llow ing ra in o r flooding.

2. F reshw ater m eadow s: land w ith w aterlogged soil fo r up to 3 m on ths each year b u t w here surface w ater is shallow an d transien t.

3. Shallow freshw ater m arshes: land w ith w ater­logged soil th roughou t the year, an d w here surface w ater m ay be p resen t fo r 6 to 9 m onths.

4. D eep freshw ater m arshes: land in u n d a ted to a dep th o f m ore th an 1 m during years o f average o r above average ra in fall.

5. P erm anen t open fresh w ater: w ater storages and na tu ra l lakes deeper th an 1 m .

6 . Sem i-perm anent saline w etlands.7. P erm anen t saline w etlands.

F rom ou r know ledge o f the h ab ita ts o f adu lt G. cleaveri, shallow freshw ater m arshes (cat­egory 3) and deep freshw ater m arshes (category 4) appear to p rov ide p erm anen t areas o f hab ita t. F looded r iver flats and freshw ater m eadow s m ay be used tem porarily by the species during m ig ration o f w h iteba it o r m ig ration o f adu lts to estuarine areas. O pen fresh w ater (category 5) is un likely to be used, particu larly i f lack ing veg­etation . T here is no ev idence to suggest th a t

. saline w etlands (categories 6 and 7) p rov ide su it­able hab itats.

In a study o f the Snowy R iver and G ippsland Lakes catchm ents, C orrick & N o rm an (1980) concluded th a t 25% o f shallow and 34% o f deep freshw ater m arshes have been lost. W ith in the P o rt P h illip Bay region, valuab le w etlands lost include the E d ith v a le -C arru m -S ea fo rd Sw am ps (C ham pion 1977, D onnelly et al. 1985) and the sw am ps o f the low er Y arra and M aribyr- nong R ivers (C astelnau 1872, excerpts from a d iary kept by J. F lem ings rep rin ted in Shilling- law 1879, K enyon 1934, and D ucker 1985). A fter study ing w etlands betw een P o rt P h ill ip Bay and M t E m u C reek in w estern V ictoria, C or­rick (1982) concluded th a t 79% o f shallow and 66% o f deep freshw ater m arshes had been lost since E uropean settlem ent, an overall loss o f 73% o f po ten tia l G. cleaveri hab ita t. T he m ost extensive hab ita t loss, how ever, is in South G ippsland w here 95% o f the na tu ra l freshw ater w etland once p resen t has been destroyed (C or­rick 1981). South G ippsland also inc ludes the largest areas o f po ten tia l G. cleaveri h ab ita t because it con ta ins coasta l-d ra in ing w etlands only w ith in 40 km o f the coast, un like the o ther areas w here w etlands ex tend as far as 150 km in land.

M ore than 23,000 ha o f w etlands have been lost in South G ippsland , inc lud ing K oo-W ee- R up, C ard in ia and Y allock Sw am ps, and sw am ps along the Pow lett and T arw in R ivers.

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C orrick (1981) p red ic ted fu rthe r loss o f w etland areas th rough drainage, clearing, cu ltiva tion and flood m itiga tion and irrigation works. H is p re­d ic tion appears fulfilled because ca lcu lations from recent stud ies o f th is area (C orrick unpub l. data) show an overall loss o f 99% o f po ten tia l G. cleaveri h ab ita t (shallow freshw ater marshes* 94%, deep freshw ater m arshes 99%).

T he loss o f such large areas o f h ab ita t su itab le fo r G. cleaveri m ust be the greatest th rea t to th is species in V ic to ria in recent tim es and m ay ac­coun t fo r its fragm ented d istr ibu tion . S im ilarily, F rankenberg (1974) stated th a t the range o f G. cleaveri in T asm an ia had undoub ted ly been fragm ented due to the d ra in ing and clearing o f sw am ps.

In N ew Z ealand popu la tions o f the th ree species o f m udfish have declined drastically w ith the loss o f h ab ita t due to sw am p drainage, deve lopm ent and agricu ltura l practices (M cD ow all 1990). W hilst concern has been ex­pressed fo r all th ree species, Skrzynski (1968) and E ldon (1979b) have questioned w hether Neochanna burrowsius can surv ive, especially w ith con tinued agricu ltu ra l m odifications. C adw allader (1975) suggested th a t p reservation o f h ab ita t areas th rough the estab lishm ent o f re­serves should be instigated for th is species. A popu la tion o f N. burrowsius estab lished in an artific ial pond (E ldon 1988) surv ived for several years before dying ou t as a resu lt o f a pro longed drough t (N Z M A F 1990)

O ther th rea ts to adu lt G. cleaveri, such as in terspecific com petition and p redation by in ­troduced trou t, Salmo trutta, Oncorhynchus m ykiis o r redfin, Perea fluvialitis, are unlikely to be m ajor, especially in sw am py hab ita ts w ith poo r w ater quality unsu itab le to these species. G. cleaveri w h itebait m ay be subject to p redation , how ever, w hilst m igrating upstream . H ab ita t d istu rbance and com petition from o ther in tro ­duced species such as carp, Cyprinus carpio, goldfish, Carassius auratus, and tench, Tinea tinea, are possib le bu t difficult to assess. Sedi­m en ta tion is un likely to affect G. cleaveri unless the h ab ita t areas becom e com pletely filled.

Because G. cleaveri is restric ted to a special­ised aqua tic hab ita t, c lim atic changes m ay have serious im pacts, although the im pact o f the G reenhouse Effect is as difficult to p red ic t as it is fo r o ther native species (B urchm ore 1990). Low er w in ter ra in fa ll m ay affect spaw ning and particu larly access to the sea, and an increase in the tida l l im it m ay a lte r availab le w etland hab i­ta t fo r m atu re G. cleaveri.

In a recen t rev iew o f the co nserva tion sta tus o f na tive fish in V ic to ria (K oehn & M orison 1990) G. cleaveri was listed as vu lnerab le , a category includ ing “ taxa no t p resen tly endangered bu t w hich are a t risk by hav ing sm all p opu la tions an d /o r by occupying restr ic ted h ab ita ts suscep­tib le to rap id en v ironm en ta l change an d /o r popu la tions w hich are declin ing a t a ra te th a t w ould render them endangered in the n ea r fu tu re ” . A lthough we have docu m en ted ad ­d itiona l localities fo r G. cleaveri, o u r resu lts re in force the ra rity o f the species. T he red u c­tions in availab le freshw ater w etlands an d on ­going th rea ts to such h ab ita ts ju s tify th e re te n ­tion o f G. cleaveri in the vu lnerab le category.

C O N C L U SIO N S

G. cleaveri is m ore w idespread in V ic to ria th an prev iously believed, occupying n a tu ra l and m odified hab ita ts along low land coasta l areas, a t least from W ilsons P rom o n to ry to the w estern Otways. T here is a need fo r fu rth e r surveys to determ ine the range o f the species in sw am py hab ita ts w ith in and ou tside o f th is area, p a r ticu ­larly on F rench Island w hich con ta ins rem n an t tea-tree sw am p h ab ita t th a t once ex isted th roughou t the K oo-W ee-R up sw am p area and the en tire W estern P o rt ca tchm ent. T he d is­covery o f G. cleaveri in th is area w ould strengthen argum ents th a t p resen t p opu la tions are rem nan ts o f a once m uch larger, m o re u n i­form ly d istr ibu ted popu la tion . C o llection o f w h itebait as they ascend coasta l s tream s m ay also be a useful m ethod o f determ in ing G. cleav­eri d is tr ibu tion (K oehn & O ’C onno r 1990a).

T he behav iou r and h ab ita t needs o f th is species are s im ilar to those o f the N ew Z ea land m udfishes. T he specific h ab ita t needs o f G. cleaveri m ake it particu larly susceptib le to h ab i­ta t changes; therefo re the m assive reduc tions in su itab le freshw ater w etland h ab ita ts have u n ­doubted ly been the greatest th rea t to the species. T he m anagem ent and conservation o f such w et­land areas are v ita l fo r the p reserva tion o f G. cleaveri in V ictoria.

A C K N O W L E D G E M E N T S

W e th an k Bill O ’C onnor, D am ien O ’M ahony and M athew W estaw ay for field assistance, D av id D enney for local in fo rm ation , A ndrew C orrick fo r the use o f unpub lished d a ta and D arw in E vans for h is com m ents on th e m an u ­script. W ordprocessing was com pleted by K ae

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W inch and Irene P ren tice. T h is w ork w as com ­p leted as p a r t o f the S ilv icu ltu re System s P ro ject funded by the D ep a rtm en t o f C onservation and E nv ironm en t, V icto ria.

R E FE R E N C E S

A l l e n , G . R ., 1989. F resh w a ter F ish es o f A u stra lia . T FH P ub lica tions, U S A .

A n d r e w s , P. A ., 1976. A rev is ion o f the fam ily G al- ax iidae (P isces) in T asm an ia . A u stra lia n Jou r­n a l o f M a r in e a n d F resh w a ter R esea rch 27: 2 9 7 -3 4 9 .

B a c k h o u s e , G . N . & V a n n e r , R . W ., 1978. O bser­va tions on the b io logy o f the dw arf galaxiid , G a la x ie lla p u s i l la (M ack) (Pisces: G alax iidae). V ictorian N a tu ra l is t 95: 1 2 8 -1 3 2 .

B e c k , R . G ., 1985. F ie ld observations upon the dw arf galax iid G a la x ie lla p u s i l la (M ack) (Pisces: G al­ax iidae) in the south -east o f South Australia. S ou th A u stra lia n N a tu ra l is t 60: 1 2 -2 2 .

B u r c h m o r e , J. J., 1990. Im p lica tions o f the green­house effect for na tive freshwater fishes in N ew South W ales. W etla n d s 10 (1/2): 3 0 -3 2 .

C a d w a l l a d e r , P. L., 1975. D istr ib u tion and ecology o f the Canterbury m udfish, N eoch an n a burrow siu s (P h illipps) (Salm oniform es: G alax­iidae). Jo u rn a l o f the R o y a l S o c ie ty o f N ew Z e a l­a n d 5: 2 1 -3 0 .

C a d w a l l a d e r , P. L. & B a c k h o u s e , G. N ., 1983. A G u id e to the F resh w a ter F ish o f V icto ria. V ic to ­rian G overnm en t Printer, M elbourne, 249 p.

C a s t e l n a u , F. L. d e , 1872. C on tr ibu tions to the ich thyo logy o f A ustralia. P roceed in gs o f the Z o o lo g ica l a n d A c c lim a tisa tio n S o c ie ty o f V ic­to r ia 1: 2 9 -2 4 2 .

C h a m p i o n , R ., 1977. E d ith va le-C arrum -Seafo rd w etlands. G raem e Shaw, D en ton and Corker & R andall C h am p ion -C on serva tion P lanning, M elbourne.

C o r r i c k , A. H ., 1981. W etlands o f V icto r ia 2. W et­lands and w aterb irds o f South G ippsland . P ro­ceed in gs o f th e R o y a l S o c ie ty o f V icto r ia 92: 1 8 7 -2 0 0 .

C o r r i c k , A. H ., 1982. W etlands o f V icto r ia 3. W et­lands and w aterb irds betw een Port P h illip Bay and M ount Em u Creek. P ro ceed in gs o f the R o y a l S o c ie ty o f V icto r ia 94: 6 9 -8 7 .

C o r r i c k , A. H . & N o r m a n , F. I., 1980. W etlands o f V icto r ia 1. W etlands o f the Snow y R iver and G ippsland Lakes catchm en t. P roceed in gs o f the R o y a l S o c ie ty o f V icto r ia 91: 1 -1 5 .

D C E ( D e p a r t m e n t o f C o n s e r v a t i o n & E n v i r o n ­

m e n t ) , 1988. W etla n d s C on serva tio n P rog ram f o r V icto ria . V ictorian G overnm en t Printer,

‘ M elbourne.D o n n e l l y , A ., K u n e r t , C . & S c h l e i g e r , P., 1985.

Ecology and m anagem ent o f Seaford Sw am p. A study o f a rem nant w etland on the rural fringe o f m etropo litan M elbourne. G raduate Schoo l

o f E nv ironm enta l Sc ience, M onash U n iversity , E nvironm enta l R eport N o . 25.

D u c k e r , S. C., 1985. Jam es F lem ing: the first gar­dener on the R iver Yarra, V ictor ia . A rch ives o f N a tu ra l H is to ry 13: 1 2 3 -1 4 0 .

E l d o n , G . A ., 1968. N o tes on the p resence o f the brown m udfish (N eo ch an n a a p o d a G un ther) on the w est coast o f the South Island o f N ew Z eal­and. N ew Z e a la n d J o u rn a l o f M a r in e a n d F resh w a ter R esea rch 2: 3 7 -4 8 .

E l d o n , G. A ., 1969. O bservations on grow th and be­hav iou r o f G alax iidae in aquarium s. T u a ta ra 17: 3 4 -4 6 .

E l d o n , G. A ., 1971. Suspected terrestr ia l d ep osit ion o f eggs by N eo ch a n n a a p o d a G un ther (P isces: Salm on iform es: G alax iidae). J o u rn a l o f F ish B io lo g y 3: 2 4 7 -2 4 9 .

E l d o n , G. A ., 1978. T he life h isto ry o f N eo ch a n n a a p o d a G un ther (P isces: G alax iidae). N e w Z e a l­a n d M in is tr y o f A g r icu ltu re a n d F ish eries, F ish er ies R esea rch B u lle tin 19: 1 -4 4 .

E l d o n , G . A ., 1979a. B reeding, grow th and aest iv ­a tion o f the C anterbury m udfish, N eo ch a n n a bu rrow sius (Sa lm on iform es: G a lax iidae). N ew Z e a la n d J o u rn a l o f M a r in e a n d F resh w a ter R esea rch 13: 3 3 1 -3 4 6 .

E l d o n , G . A ., 1979b. Can the Canterbury m udfish survive? C atch (N Z ) 6: 19.

E l d o n , T., 1988. Canterbury m udfish estab lished in a new pond. F resh w a ter C atch 36: 5.

F l e t c h e r , H . J., 1907. N o tes and exh ib its. P ro ceed ­ings o f th e L in n a ea n S o c ie ty o f N e w S ou th W ales 31: 4 3 0 -4 3 1 .

F r a n k e n b e r g , R. S., 1967. T he vertebrate fauna o f the Bass Strait Islands. T he ga lax iid fishes o f F linders and K ing Islands. P ro ceed in g s o f th e R o y a l S o c ie ty o f V icto r ia 80: 2 2 5 -2 2 8 .

F r a n k e n b e r g , R. S., 1974. N a t iv e freshw ater fish. In B io g eo g ra p h y a n d E co lo g y in T a sm a n ia (M o n - og ra ph iae B io lo g ica e 25), W . D . W illiam s, ed ., W . Junk, T he H ague, 1 1 3 -1 4 0 .

F u l t o n , W ., 1986. T he T asm an ian m ud fish G a la x ia s cleaver i. F ishes o fS a h u l 4: 1 5 0 -1 5 1 .

F u l t o n , W ., 1990. T a sm a n ia n F resh w a ter F ishes. Fauna o f T asm an ia H andbook N o . 7, Fauna o f T asm an ia C om m ittee, H obart.

G l o v a , G . J. & S a g a r , P. M ., 1989a. F eed in g in a nocturnally active fish, G a la x ia s b revip in n is, in a N ew Z ealand stream . A u stra lia n J o u rn a l o f M a r in e a n d F resh w a ter R esea rch 40: 2 3 1 -4 0 .

G l o v a , G . J. & S a g a r , P. M ., 1989b . Prey se lection by G a la x ia s vu lgar is in the H aw k ins R iver , N ew Zealand. N ew Z e a la n d J o u rn a l o f M a r in e a n d F resh w a te r R esea rch 25: 1 5 3 -1 6 1 .

G r e e n , R. H ., 1984. T he T asm an ian m udfish on F lin ­ders Island. T a sm a n ia n N a tu ra l is t 77: 7.

H a l l , T. S., 1901. A burrow ing fish (G a la x ia s sp.). V ictorian N a tu ra l is t 18: 6 5 -6 6 .

H u m p h r i e s , P. L., 1985. A spects o f b io logy o f the dw arf galaxiid , G a la x ie l la p u s i l la (M ack) (Sal­m on iform es: G alax iidae). BSc (H on s) thesis, M onash U n iversity , C layton , V ictoria:

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H u m p h r i e s , P. L., 1986. O bservations on the eco logy o f G a la x ie lla p u s il la (M ack) (Salm oniform es: G alax iidae) in D iam on d Creek, V ictor ia . P ro ­ceed in gs o f th e R o y a l S o c ie ty o f V icto r ia 98: 1 3 3 -1 3 7 .

H u m p h r i e s , P. L., 1989. V aria tion in the life h istory o f diad rom ous and land locked popu la tions o f the spotted galaxias, G a la x ia s tru ttaceu s V a len­ciennes, in Tasm an ia . A u stra lia n J o u rn a l o f M a r in e a n d F resh w a ter R esearch 40: 5 0 1 - 518.

J a c k s o n , P. D . & D a v i e s , J . N . , 1982. O ccurrence o f the T asm an ian m udfish, G a la x ia s c leaver i Scott, on W ilsons Prom ontory: first record from m ain land A ustralia. P ro ceed in gs o f the R o y a l S o c ie ty o f V icto r ia 94: 4 9 -5 2 .

K e n y o n , A . S., 1934. H eide lberg , th e C ity o f S tream s. C ity o f H eidelberg C entenary C elebrations C om m ittee.

K o e h n , J. D ., 1990. A B ib lio g ra p h y o f R esea rch P u b ­lica tio n s b y S ta f f o f the F resh w a ter F ish M a n ­a g em en t B ranch, F ish er ies D iv is ion , 1 9 7 0 -9 0 . Arthur R ylah Institu te for E nv ironm en ta l R e­search T echn ical R eport Series N o . 102, D e ­partm ent o f C onservation, Forests and Lands, V ictoria.

K o e h n , J. D . & M o r i s o n , A. K . , 1990. A review o f the conservation status o f na tive freshwater fish in V ictor ia . V ictorian N a tu ra l is t 107: 1 3 -2 5 .

K o e h n , J. D . & O ’C o n n o r , W . G ., 1990a. T he d istr i­bu tion o f freshwater fish in the O tway R egion, south-w estern V ictoria. P roceed in gs o f the R o ­y a l S o c ie ty o f V icto r ia 102: 2 9 -3 9 .

K o e h n , J. D . & O ’C o n n o r , W. G ., 1990b. Threats to V ictorian na tive freshwater fish. V ictorian N a tu ra l is t 107: 5 -1 2 .

K o e h n , J. D . & O ’C o n n o r , W . G ., 1 9 9 0 c . B io lo g ica l In fo rm a tio n fo r M a n a g e m e n t o f N a tive F resh w a ter F ish in V ictor ia . G overnm en t Printer, M elbourne, 165 p.

K o e h n , J. D ., M c K e n z i e , J. A . , O ’C o n n o r , J. P ., O ’C o n n o r , W . G ., O ’M a h o n y , D . J., R a a d i k ,

T . A . , S a d d l i e r , S . R. & T u n b r i d g e , B . R., 1991. M isce lla n eo u s S u rveys o f F resh w a ter F ish in V ictoria. A r t h u r R y l a h I n s t i t u t e f o r E n v i r o n ­

m e n t a l R e s e a r c h T e c h n i c a l R e p o r t S e r ie s N o .

110, D epartm en t o f C onservation and E nv iron­m en t, V ictoria.

M c D o w a l l , R. M ., 1978. G eneralised tracks and d is­persal in b iogeography. S y s te m a tic Z o o lo g y 27: 8 8 -1 0 4 .

M c D o w a l l , R. M ., 1990. N e w Z e a la n d F resh w a te r F ishes. A N a tu ra l H is to ry a n d G u ide. H e in e- m ann R eed , A uck land , N ew Z ea land , 553 p.

M c D o w a l l , R. M . & F r a n k e n b e r g , R . S . , 1981. T he galaxiid fishes o f A ustralia. R ec o rd s o f th e A u s­tra lian M u se u m 33: 4 4 3 -6 0 5 .

M c D o w a l l , R. M . & P u s e y , B. J., 1983. L e p id o g a l- a x ia s sa la m a n d ro id e s M ees - a redescr ip tion , w ith natural h isto ry no tes. R ec o rd s o f th e W estern A u stra lia n M u se u m 11: 1 1 -2 3 .

M c D o w a l l , R. M . & W h i t a k e r , A. M . , 1975. T he freshw ater fishes. In B io g eo g ra p h y a n d E co lo g y in N ew Z e a la n d (M o n o g ra p h ia e B io lo g ica e 27),G . K uschel, ed ., W . Junk, T he H ague, 2 7 7 - 299.

M e r e d i t h , A . S . , 1985. M etabo lism and cu taneous exchange in an am ph ib ious fish, N eo ch a n n a burrow sius (P h illipps). P h D thesis, U n iversity o f Canterbury, Christchurch.

N Z M A F ( N e w Z e a l a n d M i n i s t r y o f A g r i c u l t u r e

a n d F i s h e r i e s ) , 1990. F resh w a ter F ish er ies C en tre A n n u a l R ep o rt, 1989 . M A F , W ellington , N ew Zealand.

P o l l a r d , D . A . , 1972. T he b io logy o f a land locked form o f the norm ally ca tad rom ous sa lm on i- form fish G a la x ia s m a cu la tu s (Jenyns). 3. Structure o f gonads. A u stra lia n J o u rn a l o f M a r ­ine a n d F resh w a ter R esea rch 23: 1 7 -3 8 .

S c o t t , E. O. G ., 1934. O bservations on som e T asm an ­ian fishes, w ith descr ip tions o f new species. P apers a n d P roceed in gs o f th e R o y a l S o c ie ty o f T a sm a n ia (1933): 3 1 -5 3 .

S c o t t , E. O. G ., 1936. O bservations on fishes o f the fam ily G alaxiidae. Part 1. P a p ers a n d P ro ceed ­ings o f the R o y a l S o c ie ty o f T a sm a n ia (1935): 8 5 -1 1 2 .

S c o t t , E. O. G ., 1971. On the occurrence in T asm an ia and on F linders Island o f B ra ch y g a la x ia s E igenm ann, 1928 (P isces: G a lax iidae) w ith d e­scrip tion o f tw o new species. R eco rd s o f th e Q ueen V icto r ia M u seu m L a u n cesto n 37: 1 - 14.

S h i l l i n g l a w , J. J., 1879. H is to r ic a l R eco rd s o f P o r t P h illip B ay. V ictorian G overn m en t Printer, M elbourne.

S k r z y n s k i , W ., 1968. T he C anterbury m udfish, G a l­a x ia s bu rrow sius Ph illipps, a van ish ing species. N ew Z e a la n d J o u rn a l o fM u r in e a n d F resh w a ter R esearch 2: 6 8 8 -9 7 .

T h o m p s o n , F. V ., 1987. N o tes on the b io logy o f the black m udfish. F resh w a ter C a tch 32: 6 -1 0