||Zoology 250 (2017)
WHY STUDY INVERTEBRATE ZOOLOGY?
(click on tree to see full cladogram)
Why study invertebrate biology?
- 1) TECHNICAL REASON: to learn proper names of animals and their parts. We need a vocabulary to talk about animals.
- 2) PRACTICAL REASONS:
- invertebrates are food for many vertebrates (wildlife management)
- many agricultural pests are invertebrates
- many invertebrates are deadly to humans as parasites (nematodes) or as vectors for serious human diseases (mites, mosquitoes)
- knowing basic invertebrate biology can yield valuable clues about human biology; evidence that life has a common heritage:
- field of immunology founded by Elie Metchnikoff in 1883 based on the simple observation of clumping amoebocytes in injured starfish larvae; he later won the Nobel prize in medicine
- model invertebrate systems (e.g., nematodes, fruit flies) help us understand gene functions & possible roles in human disorders
- light-emitting jellyfish yielded a molecule to visualize calcium
- 3) AESTHETIC REASONS: for the joy of discovering extraordinary forms & abilities of animals (some discoveries make national news)
- Many are stunningly beautiful:
- Impressively large body sizes:
- the largest living invertebrate is 19 m long, weighs over 500 kg, and can swim at 25 kph in water! (giant squid)
- crabs may have a leg span exceeding 4 m! (Japanese spider crab)
- earthworms may exceed 3 m in length! (Australian earthworm)
- marine ribbon worms may reach 30 m in length! (Nemertea)
- worms 2 m long & 3-4 cm diam. have no gut! (Vestimentifera)
- Impressively large body parts:
- worms with a proboscis 350X longer than body! (Echiura)
- crab with one claw at 40% of total body weight! (fiddler crab)
- Impressive abilities, some dangerous to humans:
- amazing mimicries (e.g., 'wonderpus' octopus) and symbioses
- shrimp that can snap fish out of the water, or pulverize a snail shell by pounding! (mantis shrimps)
- snails that paralyze fish & swallow them whole! (cone snails)
- 4) CONCEPTUAL REASON: The Tree of Life is a grand vision
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Copyright (c) 2017 by A. Richard Palmer. All rights reserved.
(revised Dec. 19, 2016)