Invertebrate Zoology: Study Guide - T. A. Dauda 2014

Multicellular Animals
Coelenterates
Class Scyphozoa

This relatively small Class (200 species) includes jellyfish that inhabit marine environments exclusively. Scyphozoan jellyfish are typically large, ranging from a few centimeters to 2 m in diameter, and are free-swimming Coelenterates. Structurally, they resemble a hydra turned inside out in the shape of an umbrella, with the oral opening facing downward. The bulk of a scyphozoan's body is composed of an amorphous substance called mesoglea, which contains up to 98% Water. The stinging Cells of large jellyfish can cause a burning sensation upon contact with human Skin.

Image

Fig. 14 Development of the scyphozoan jellyfish Aurelia:

1 — egg; 2-6 — developing scyphomedusa larvae; 7 — adult jellyfish.

A polyp develops from the fertilized eggs of scyphozoan jellyfish. It has a short lifespan but gives rise to new jellyfish (Fig. 14). In many of our country's seas, the moon jellyfish is a commonly encountered species.



Last update: 13/08/2026

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