BIOL110 Lecture Notes - Lecture 13: Crustacean Larvae, Circulatory System, Symmetry In Biology
9 Dec 2016
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Document Summary
No nephridia, but other types of excretory organs. Main body cavity is hemocoel instead of coelom in annelids. Molt exoskeleton to increase in size (ecdysis!) Mostly saltwater, also freshwater, some parasitic, rarely on terrestrial. Joints have appendages: all appendages, except first antenna, are biramous (2 main branches coming from one, presence of nauplius larvae (babies, bilateral symmetry, 2 antennae, 3 tagmata (head, thorax, abdomen, compound eyes. External features: rostrum on head, not segmented tail called telson. Dorsal covering carapace, covers head an forearms, not found in all crustaceans first antenna is eudiram. Feeding in crustacea some filter feed small particles (shrimp) some aggressive hunters (manta shrimp), huge spears that emerge from burrows or strong appendages that can destroy bivalve shells. Once they get food, appendages move food in mouth, stomach does most of the shredding inside. Hard areas in stomach used to grind up food then moves to digestive tract.
