Mollusc

Intertidal bivalves have been used extensively to study bioenergetic responses of organisms to oxygen limitation. Of particular note is the excellent series of papers on the bay mussel Mytilus edulis [10,12,35,58,59], which soundly established the utility of calorespirometry and provided an excellent experimental data base and theoretical concepts for future testing. Useful reviews of this work exist [3,13], so 1 will not reevaluate the work and its implications here, except to point out that the studies contributed to, among other issues, the ongoing debate over the existence of an anaerobic exothermic gap in invertebrates (see section 3.2) 

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The mechanism by which TBT causes these effects has been extensively stiidied. The androgenic effects of TBT appear to be caused by interference with steroid biosynthesis rather than by mimicking the action of testosterone at the androgen receptor. Exposure of female molluscs to TBT leads to an elevation in testosterone in the haemolymph. " Much of the experimental evidence... 

Crustaceans, molluscs etc. disappear White moss increases Salmon, char, trout and roach die Salamander eggs fail to hatch... 

Furthermore, as shown in Figure 5.28, the number of amino acid differences between two cytochrome c sequences is proportional to the phylogenetic difference between the species from which they are derived. The cytochrome c in humans and in chimpanzees is identical human and another mammalian (sheep) cytochrome c differ at 10 residues. The human cytochrome c sequence has 14 variant residues from a reptile sequence (rattlesnake), 18 from a fish (carp), 29 from a mollusc (snail), 31 from an insect (moth), and more than 40 from yeast or higher plants (cauliflower). 

A major biological sink for CO9 that is often overlooked is the calcium carbonate shells of corals, molluscs, and Crustacea. These invertebrate animals deposit CaCOa in the form of protective exoskeletons. In some invertebrates, such as the sderaetinians (hard corals) of tropical seas, photosynthetic dinoflagellates (kingdom Protoctista) known as zooxanthellae live within the ani-... 

In Mollusca, bioluminescence occurs in a great variety of organisms having distinctly different appearances, such as the classes Gastropoda (limpets, snails and sea hares), Bivalvia (clams), and Cephalopoda (squids and octopuses). All luminous molluscs currently known are marine organisms, except the New Zealand fresh water limpet Latia neritoides and the Malaysian land snail Quantula (Dyakia) striata. No information is yet available on the biochemical aspects of the Quantula luminescence. 

Dunstan, S. L., et al. (2000). Cloning and expression of the bioluminescent photoprotein pholasin from the bivalve mollusc Pholas dactylus. J. Biol. Chem. 275 9403-9409. 

Suter, H. (1890). Miscellaneous communications on New Zealand land and fresh water molluscs. Trans. N.Z. Inst. 23 93-96. 

Biogenic A. Calcareous B. Siliceous >30 >30 48 Foraminifera, coccoliths, calcareous algae, molluscs, bryozoa, and corals 14 Diatoms and radiolaria... 

Schoeninger, M.X and Peebles, C.S. 1981 Effect of mollusc eating on human bone strontium levels. Journal of Archaeological Science 8 391-397. 

Matthiessen, P. and Gibbs, PE. (1998). Critical Appraisal of the Evidence for TBT-Mediated Endocrine Disruption in Molluscs—A concise review of effects of TBT on molluscs. Scheuhammer, A.M and Sandheimich, M.B (Eds.) (2008). Special issue of the journal Ecotoxicology devoted to effects of methyl mercury on wildlife, which gives recent results of field studies conducted in North America. 

Jobling, S., Casey, D., and Rodgers-Gray, T. et al. (2003). Comparative responses of molluscs and fish to environmental estrogens and an estrogenic effluent. Aquatic Toxicology. 65, 205-220. 

Livingstone, D.R. (1985). Responses of the detoxification/toxication enzyme system of molluscs to organic pollutants and xenobiotics. Marine Pollution Bulletin 16, 158-164. 

Livingstone, D.R., Moore, M.N., and Widdows, J. (1988). Ecotoxicology Biological effects measurements on molluscs and their use in impact assessment. In W. Salomans, B.L. Bayne, E.K. Duursma, and U. Forstner (Eds.) Pollution of the North Sea An Assessment. Berlin Springer-Verlag 624—637. 

Matthiessen, P. and Gibbs, P.E. (1998). Critical appraisal of the evidence for TBT-mediated endocrine disruption in molluscs. Environmental Toxicology and Chemistry 17, 31-A3. 

Crustaceans, molluscs etc. disappear White moss increases... 

Certain occluders also discriminate among Na channels from neuronal and skeletal muscle. But in this case the blocking ligands are small peptides, the x-conotoxins from the mollusc Conus geo aphus. This molecule binds tightly to muscle Na channels, effectively reducing Na current (55 see Figure 6A), and also can displace bound... 

The cx)ne snails are predatory, venomous molluscs which use a common general strategy to capture prey (i, 5-7). All 300-500 species of Conus have a specialized venom apparatus, diagrammed in Figure 1 (8). A venom paralytic to the prey is produced in a venom duct and injected through a disposable, harpoon-like tooth (Figure 2). Paralysis of the prey can be remarkably rapid in the case of certain piscivorous cone species, the fish prey is immobilized in less than one second. 

In the order Muricidae these carnivorous snails attack molluscs or sessile crustaceans by boring holes in their shells using softening secretions. Hypobranchial and other glands contain small molecular weight substances with pharmacological activity (e.g., murexine, 5HT, etc.). 

Mollusca and Arthropoda. A variety of pharmacological actions are induced by the toxins found in molluscs (17). For example, surugatoxin is a potent mydriatic (5J), ganglion blocker (84), and a potent hypotensive agent in cats. 

Murexine and related compounds have marked actions on the nicotine receptor as expected from choline esters (87-89). Toxins from the digestive glands of nudi-branchs have marked effects on the cardiovascular system of the rat (23). Antiviral and antibacterial substances have been obtained from molluscs (90,91). 

Ice scouring of the intertidal zone in arctic waters makes this virtually sterile. This was noted more than 170 years ago by Keilhau (1831)—so that attention was directed to components of the subtidal zone to which little attention had previously been directed, and which was expected to be particularly sensitive to oil spills. Changes in the components of the macrobenthos including infauna, epibenthos, and macroalgae were examined, and attention was also directed to the histopathological and biochemical responses of bivalve molluscs that were affected in different ways by exposure to the dispersed and the undispersed oil. 

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