Invertebrate DiversityChapter 33

The Ancestors

• Protists: Choanoflagellates– Colonies formed/ turned into super

colonies

Porifera – The Sponges

Porifera – The Sponges

• Asymmetrical body plan• No tissue layer• Sexual reproduction -

hemaphroditic• Sessile filter feeder• Grouped based on

“skeleton” type.• Can form gemmules for

protection.

Gemmules

Cnidaria

• Examples: jellyfish, anemones, hydra and coral

Cnidaria

• Named for cnidocytes

Cnidaria

• Diploblastic• Two body forms: polyp & medusa• Grouped based on amount of life spent as

polyp or medusa

Cnidaria

Platyhelminthes - Flatworms

• Examples: planaria, liver flukes, tapeworms

Platyhelminthes - Flatworms

• Bilateral symmetry• Simple organ

systems• Reproduce sexually

and asexually• Acoelomate• Triploblasitc• Most are parasitic

Rotifera

Named for feeding rotorsPseudocoelomatesReproduce via parthenogenisisHave an anus!

Images from http://www.microscopy-uk.org.uk

Nematoda – Roundworms• Found in most aquatic habitats, soil, and in plant and animal tissues• Parasitic – hookworms, pinworms, round worms, heart worms

.

Nematoda – Roundworms

• Pseudocoelomates

• Simple organs

Annelida – Segmented Worms

• Examples: earthworms, fireworms, leeches

Annelida – Segmented Worms

• “Little rings” –repeating segments, some specialized

• Coelomates• Setae• Parapodia

Annelida – Segmented Worms

• Fairly complex anatomy

Mollusca

• Largest classes:– Gastropods– Bivalves– Cephalopods

MolluscaMuscular foot Head

Visceral Mass

Arthropoda• “Jointed foot”• Crustaceans-hexapods-myriapods-cheliceroforms

Arthropoda

• Most successful animal phyla – 67% of all species!

Arthropoda• Exoskeleton – ecdysis• Open circulatory system• Tracheal tubes• Spiracels vs. book lungs• Malpighian tubules

Echinodermata

• “Spiny Skin”• No head or brain• Radial symmetry• Simple anatomy• Deuterostomes• Endoskeleton• Tube feet• Water vascular system

classificationKingdom: Animalia

Phylum: Arthropoda

Class: Arachnida

Order: Araneae

Family: Theridiidae

Genus: Latrodectus

Species• Latrodectus Walckenaer, 1805• Latrodectus antheratus (Badcock, 1932) — Paraguay, Argentina• Latrodectus apicalis Butler, 1877 — Galapagos Islands• Latrodectus bishopi Kaston, 1938 — USA• Latrodectus cinctus Blackwall, 1865 — Cape Verde Islands, Africa, Kuwait• Latrodectus corallinus Abalos, 1980 — Argentina• Latrodectus curacaviensis (Müller, 1776) — Lesser Antilles, South America• Latrodectus dahli Levi, 1959 — Middle East to Central Asia• Latrodectus diaguita Carcavallo, 1960 — Argentina• Latrodectus elegans Thorell, 1898 — China, Myanmar, Japan• Latrodectus erythromelas Schmidt & Klaas, 1991 — Sri Lanka• Latrodectus geometricus C. L. Koch, 1841 — Cosmopolitan• Latrodectus hasselti Thorell, 1870 — Southeast Asia to Australia, New Zealand• Latrodectus hesperus Chamberlin & Ivie, 1935 — North America, Israel• Latrodectus hystrix Simon, 1890 — Yemen, Socotra• Latrodectus indistinctus O. P.-Cambridge, 1904 — Namibia, South Africa• Latrodectus karrooensis Smithers, 1944 — South Africa• Latrodectus katipo Powell, 1871 — New Zealand• Latrodectus lilianae Melic, 2000 — Spain• Latrodectus mactans (Fabricius, 1775) — probably native to North America only (introduced elsewhere)• Latrodectus menavodi Vinson, 1863 — Madagascar, Comoro Islands• Latrodectus mirabilis (Holmberg, 1876) — Argentina• Latrodectus obscurior Dahl, 1902 — Cape Verde Islands, Madagascar• Latrodectus pallidus O. P.-Cambridge, 1872 — Cape Verde Islands, Libya to Russia, Iran• Latrodectus quartus Abalos, 1980 — Argentina• Latrodectus renivulvatus Dahl, 1902 — Africa, Saudi Arabia, Yemen• Latrodectus revivensis Shulov, 1948 — Israel• Latrodectus rhodesiensis Mackay, 1972 — Southern Africa• Latrodectus tredecimguttatus (Rossi, 1790) — Mediterranean to China• Latrodectus variegatus Nicolet, 1849 — Chile, Argentina• Latrodectus variolus Walckenaer, 1837 — USA, Canada