1) TECHNICAL REASON: to learn proper names of animals and their parts. We cannot communicate about animals until we name them.
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 yields insights into human biology; evidence that life has a common heritage:
field of immunology founded by Metchnikoff in 1883 based on the simple observation of clumping amebocytes 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)
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:
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
