Invertebrates 2 flatworms, molluscs & annelids

B active predators with well developed sense organs a

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(b) Active predators with well developed sense organs & a complex brain (i) Ancestors (ii) Tentacles used to grasp prey (iii) Poison in saliva
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Invertebrates -2: Platyhelminthes, Mollusca & Annelida Page 6 of 9 (c) Fire jets of water from excurrent siphon to move (d) Eject ink when alarmed (not nautilus) Annelids (Phylum Annelida) 1. Segmented worms (a) The segments are called ________________. (b) The division of the body into segments is called ____________________. (c) There are three classes 2. Oligochaetes (e.g. earthworms) (a) External features (i) Prostomium (ii) Pygidium (iii) Annuli (iv) Citellum (v) Chaetae (b) Locomotion is by peristalsis of hydrostatic skeleton (i) Coeleom (ii) Circular & longitudinal muscles (iii) Chaetae
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