SLE204 Lecture Notes - Lecture 11: Box Jellyfish, Manowar, Mesoglea
9 Aug 2018
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4 classes: hydrozoa, scyphozoan , cubozoa, anthozoa. Hydra, obelia, physalia (portugese man-o-war) jelly fish cube jellyfish. Characteristics: have nematocysts stinging cells (only in cnidarians) Mouth at one end surrounded by tentacles. Aboral end usually attached to substratum by pedal disk. 2 morphological types: medusa jellyfish form adapted to floating/free swimming lifestyle. Tentacles extend from rim and surround the mouth helps move the food towards the mouth. Class hydrozoa: most are marine, colonial, asexual polyp; sexual medusa, e. g. Hydra: freshwater hydrozoan, sessile; but moves using somersaulting motion, solitary polyps, polyp structure: Penetrate prey and inject poison to immobilize it. Recoil and entangle prey (with its tentacles) Secrete adhesive substance to attach themselves to their prey: move by summersaulting or gliding on basal disk. Obelia: marine hydrozoan, looks like a plant. Structure: base, stalk, terminal polyps, colonial is a colony of polyps.
