Molluscs to three different aquatic biomes.

Introduction: Molluscs are one of the most diverse groups of invertebrate fleshlys - some(prenominal) in form and habitat. Therefore the study of molluscs has captured the interest of incompetent and scientists alike for many centuries they have figured prominently in paleobiological and biological studies, and have served as study organisms in numerous evolutionary, biomechanical, ecological, physiological, and behavioural studies (Little, 1990) Within the phylum Mollusca, snails and slugs make up the largest molluscan group, and have thence been canvas most extensively. They are so named because their foot spreads by when the animal crawls about (Little C 1990). The cerebral ganglion of several species (e.g., Euhadra peliomorpha, genus Tethus californica, and Lymnaea stagnalis) secretes a neurohormone that stimulates the hermaphroditic sex gland (the reproductive secretor that contains both virile and female characteristics); hermaphroditism is a harsh condition among molluscs. This gonadotrophic peptide hormone is stored in a regular(prenominal) neurohemal organ until its incommode is stimulated. For example, phototropic information detected by the questionable optical gland can direct the release of the gonadotrophic hormone. The hermaphroditic gonad of Euhadra secretes testosterone, which stimulates formation of a gland that releases a pheromone for influencing mating behaviour. The optic gland of the octopus (of the class Cephalopoda) influences knowledge of the reproductive variety meat on a seasonal worker basis. It is not known, however, whether any neurohormones are involved or whether this is strictly a neurally controlled event.

All molluscs have a similar personate plan with three main part: *         a foot, *         a visceral hoi polloi, *         a mantle. The foot is utilise for movement, the visceral bay window contains most of the internal organs, and the mantle is a heavy deal of tissue over the visceral mass from which a subject may develop. The mantle cavity is an lengthiness of the mantle, which contains the gills, the... thanks for the act it help me alot! i never really knew this overmuch block but now i do! thanks If you finale to get a full essay, order it on our website: BestEssayCheap.com

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