Echinoderms organisms

Although they are pigments, quinones make only small contributions to the colors of tissues and organisms that produce them. Quinones play an important role in the coloration of some fungi, lichens, insects (Coccidae), and echinoderms, but they rarely contribute to the external colors of higher plants. 

Nutritional zinc deficiency is rare in aquatic organisms (Spear 1981), although reports are available of experimentally induced zinc deficiency in algae, sponges, daphnids, echinoderms, fish, and amphibians. 

In contrast with fast, strong predators, organisms with a limited range of movement, or limited control over their movements—those that cannot run away from potential predators—are well represented among the chemically defended (Table 1). Sessile marine invertebrates are particularly accomplished chemists these include in their ranks sponges, antho-zoan corals, crinoid echinoderms, polychaetes, bryozoans, brachiopods,... 

Gastropods (snails), echinoderms (sea urchins and sea stars) and annelids (lugworms) were exposed to oil saturated sediments and assayed for AHH activity (17). Sediment was mixed with Venezuelan crude at a concentration of 0.2-0.5% and exposures were for one week (4°C) in a static system with water renewal at 2-3 day intervals. The aim was to determine if oil soaked sediments could induce AHH activity in some representative intertidal benthic organisms common to the subarctic waters of the North West Atlantic. Digestive gland homogenates from snails, sea urchins, and sea stars and a combination of intestinal and gill tissues from annelids were used in the enzyme assays. 

The phylum Echinodermata comprises about 7000 living species [177]. Echinoderm means spiny-skinned and these organisms are characterised by the tube feet, which they use to move about. These have suction discs on the ends, which operate by an internal bulb pumping water in and out of the foot, causing expansion and contraction. The phylum is sub-divided into five classes the asteroids (sea stars), the holothurians (sea cucumbers), the crinoids (sea lilies), the echinoids (sea urchins) and the ophiuroids (brittle stars) [178]. As stated in the introduction to this review, sulfated sterols and saponins, which comprise the majority of echinoderm metabolites containing sulfur, are not included here. 

The amount of collagen varies from one species to another and from tissue to tissue within the same species. Collagen comprises as much as one third of the total protein in the vertebrate body and in certain invertebrates, such as sponges and echinoderms as well as corals186, collagen may account for an even larger proportion of the total protein of the organism. 

Additionally, sulfated sterols have been described from a wide variety of marine organisms, particularly sponges and echinoderms, and several of these steroidal sulfates have exhibited a broad range of activities. Halistanol sulfates are a group of sulfated polyhydroxysteroids from... 

Echinoderms constitute a peculiar phylum of invertebrates belonging to the most highly organized animals, the Deuterostomia, including, also, all the phyla of chordates. Among the invertebrates, echinoderms are the richest in glycolipids, and differ from all of the other marine invertebrate phyla in that they contain sialoglycolipids.79 This conforms to the data of Warren, who studied the occurrence of sialic acids in Nature, and found that all of the vertebrates have them, but, of the invertebrates, only the echinoderms practically all of the Protostomia contain no sialic acids.274... 

Spectrin is a common component of the submembranous cytoskeleton. It was first identified as a major constituent of the erythrocyte membrane cytoskeleton, but has since been found in many other vertebrate tissues as well as in the nonvertebrates Drosophila, Acanthamoeba, Dictyostelium, and echinoderms (Bennett and Condeelis, 1988 Byers et al., 1992 Dubreuil et al., 1989 Pollard, 1984 Wessel and Chen., 1993). The ease with which spectrin could be isolated from erythrocyte ghosts made it an ideal candidate for the study of the biochemical processes involved in the assembly and organization of the cytoskeleton (Gratzer, 1985). 

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