Key differences, features, and comparative analysis of Phylum and Key features.
| Phylum | Key features | Examples |
|---|---|---|
| Annelida | Metameric segmentation; coelomate; closed circulation; nephridia for excretion & osmoregulation; longitudinal & circular muscles; Nereis has parapodia | Nereis, Pheretima (earthworm), Hirudinaria (leech) |
| Arthropoda (largest phylum) | Jointed appendages; chitinous exoskeleton; body = head, thorax, abdomen; open circulatory system; respiration via gills/book gills/book lungs/trachea; sensory & compound eyes | Apis (bee), Bombyx (silkworm), Laccifer (lac insect), Anopheles, Locusta, Limulus (king crab, a living fossil) |
| Mollusca (2nd largest) | Soft body covered by a mantle; usually a calcareous shell; muscular foot; radula (rasping feeding organ); gills for respiration | Pila (apple snail), Pinctada (pearl oyster), Sepia, Loligo, Octopus, Aplysia (sea hare), Dentalium, Chaetopleura |
| Echinodermata | Spiny endoskeleton of calcareous ossicles; unique water vascular system (tube feet) for locomotion, food capture & respiration; marine; adults radial but larvae bilateral | Asterias (starfish), Echinus (sea urchin), Antedon (sea lily), Cucumaria (sea cucumber), Ophiura (brittle star) |
| Hemichordata | Worm-like marine animals; have a rudimentary stomochord in the collar (not a true notochord); proboscisācollarātrunk body | Balanoglossus, Saccoglossus |
This comparison table is part of the chapter notes for Animal Kingdom. Get complete notes, flashcards, active recall sheets, and test prep modes: