Sessile marine

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,... 

Sessile marine organisms, much like their terrestrial counterparts, exist in an environment characterized by Intense competition for living space. There is considerable evidence, amid some controversy (J., 2), that many species have developed chemical expedients to Insure their survival survival may take the form of cohabitation with, domination over or eradication of competitors for space, as well as the use of toxins or feeding deterrents to repel predators. 

Many starfish cause an escape response in usually sessile marine invertebrates [7]. The starfish Dermasterias imbricata causes the sea anemone Stomphia coccinea to release its basal disc from the substratum and swim away on contact. Bioassay-directed fractionation of the starfish extract led to the isolation of the compound found to elicit this response, the benzyltetrahydroisoquinoline alkaloid imbricatine (646). The structure of compound 646 was elucidated by spectral data interpretation. The amino acid residue in imbricatine is related to the thiol containing amino acids ovothiols A-C. Imbricatine (646) is active in both LI210 and P388... 

Sessile animals (and ones that are virtually so) have much the same problems in defending themselves and warding off predators as terrestrial plants. In fact, many of these animals supplement their food supply by means of symbiotic unicellular organisms, as do a few animals that move from place to place, but slowly. Most sessile marine animals feed upon material that is either suspended in the water or deposited on the substrate. This material sometimes contains metabolites that might be put to use defensively. However, the food is usually heterogeneous and relatively unpredictable as to content therefore, it does not supply a reliable source of metabolites. It is generally not used defensively, and such use is facultative. Some bivalves, however, do concentrate saxitoxin, derived from dinoflagellates, in tissues that are exposed to predators.13... 

Vance, R.R., A mutualistic interaction between a sessile marine clam and its epibionts, Ecology, 59, 679, 1978. 

Crisp DJ (1979) Dispersal and re-aggregation in sessile marine invertebrates, particularly barnacles. In Larwood G, Rosen BR (eds) Biology and systematics of colonial organisms. System-atics association special volume no. 11. Academic, London, pp 319-327... 

Fouling n. Sessile marine organisms on the hulls of ships. 

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