SPONGES & JELLY FISH:
Sponges are mainly MARINE animals that make up the phylumporifera.They are among the simplest of all animals, having no tissues or organs. Their bodies consist of two layers of cells separated by a jelly-layer that is strengthen by mineral spicules or protien fibers. The body is perforated by a system of pores and water channels called the aquiferous system. Special cells with whip-like structures draw water through the aquiferous system, there by bringing tiny food particals to the sponge's cells. Jelly fish sea anemones and corals belong to the phylum cnidaria, also known as Coelenterata. More complex than sponges, jellyfish have simple tissues , such as a nervous tissue; a radially symmetrical body; and a mouth surrounded by tentacles with unique stinging cells.
STARFISH & SEA URCHINS:
Starfish and sea urchins make up the phylum. A unique featureof echinoderms is the water vascular system, which consist of a series of water-filled canals from which protrude thousandsof tiny tube feet. The tube feet include pentaradiate symmetry that is no body can be divided into five parts radiatind fromcentre, no head, decentralized nervous system that lacks a brain and no excretory organs.
SHARKS & JAWLESS FISH:
Sharks belong to a class of fishes called chondrichthyes which is a division of superclass jawed mouth.sharks and their relatives have a skeleton made of cartilage a characteristic that distinguishes from bony fish.Other important features of shark fish are extremely tough, tooth-like scales, ank lack of swim bladder. Jawless fish are primitive, eel like fish which have round mouths.In addition to their characteristic round, suker-like mouths and lack of jaws and also have smooth slimmy skins without scales and unpaired fins.Mostly people take this sucker fish as pets because this fish keeps the glass clean from her mouth. As there are much more sea animals and all have their diffrent characteristic and diffrent various features.