Marine invertebrates chemical defenses

Pavia H, Cervin G, Lindgren A, Aberg P (1997) Effects of UV-B radiation and simulated herbivory on phlorotannins in the brown alga Ascophyllum nodosum. Mar Ecol Prog Ser 157 139-146 Pawlik JR (1993) Marine invertebrate chemical defenses. Chem Rev 93 1911-1922 Pettit GR, Kamano Y, Herald CL, Tuinman AA, Boettner FE, Kizu H, Schmidt JM, Baczynskyj L, Tomer KB, Bontems RJ (1987) The isolation and structure of a remarkable marine animal antineoplastic constituent dolastatin 10. J Am Chem Soc 109 6883-6885 Pfander H, Stoll H (1991) Terpenoid glycosides. Nat Prod Rep 8 69-95... 

Cronin G (2001) Resource allocation in seaweeds and marine invertebrates chemical defense patterns in relation to defense theories. In McClintock JB, Baker BJ (eds) Marine chemical ecology. CRC, London, pp 325-353... 

Pawlik, J. R. (1993). Marine invertebrate chemical defenses. Chemical Reviews 93,1911-1922. 

Pawlik JR (1993) Marine Invertebrate Chemical Defenses. Chem Rev 93 1911... 

Cronin, G., Resource Allocation in Seaweeds and Marine Invertebrates Chemical Defense Patterns in Relation to Defense Theories, in Marine Chemical Ecology, McClintock, J.B. and Baker, B.J., Eds., CRC Press, Boca Raton, FL, 2001, chapt. 9. 

Pawlik, J.R. (1993) Marine invertebrates chemical defenses. Chem. Rev., 93, 1911-1922. 

Stamp N (2003) Out of the quagmire of plant defense hypotheses. Q Rev Biol 78 23-55 Steinberg PD (1988) Effects of quantitative and qualitative variation in phenolic compounds on feeding in 3 species of marine invertebrate herbivores. J Exp Mar Biol Ecol 120 221-237 Steinberg PD, de Nys R, Kjelleberg S (2002) Chemical cues for surface colonization. J Chem Ecol 28 1935-1951... 

Rather than carry a corpse, a quite different animal kidnaps a living organism as its chemical defense. This is the strategy of a tiny marine creature called an amphipod, a member of a widespread order (Amphipoda) of small crustaceans. The tens of thousands of their species represent an assortment of types and lifestyles, many looking like tiny shrimp, to which they are related. Marine amphi-pods are one of the invertebrate success stories and can be found in almost all saltwater environments, feeding on plants, animals, or detritus. Many are microscopic or nearly so. Some are at home in... 

The majority of biomonitoring studies involves analyzing the bulk contaminant concentration in the whole body or selected tissues of organisms. However, many marine organisms (both vertebrate and invertebrate) possess defense mechanisms to cope with contamination, through immobilization and accumulation in specific organs, cells, or proteins 106 accumulated contaminants can then be stored, metabolized, or excreted. In view of this, the validity of bulk chemical analyses as a measure of contaminant impact and toxicity must be questioned. 

Lindquist, N. and Hay, M. E., Palatability and chemical defense of marine invertebrate larvae, Ecol. Monogr., 66, 431, 1996. 

Paul, V. J., Chemical defenses of benthic marine invertebrates, in Ecological Roles of Marine Natural Products, Paul, V. J., Ed., Cornell University Press, Ithaca, NY, 1992, 5. 

Chemical defenses are less commonly reported in other groups of mobile marine invertebrates, but they may exist. Heine et al.21 showed that a common Antarctic nemertean worm is rejected as prey by co-occurring fishes despite the lack of obvious structural defenses. The unpalatability has been attributed to a highly acidic mucus coating (pH 3.5), although toxic peptides were also present22... 

This type of correlative approach is widespread, as only a few marine studies involving inducible defenses (and none with mobile invertebrates) have directly demonstrated that the induction results in a decrease in the susceptibility of the organism to predation.71,72 Statistically significant differences in shell thickness or concentrations of defensive chemicals may or may not meaningfully affect predator preferences in ecologically relevant field situations. For chemical defenses, compound dose-response relationships may be nonlinear, and threshold levels of defense could be sufficient to deter predators so that further induction has little additional benefit. Thus, future studies should focus on directly demonstrating whether an induced response reduces predation on prey organisms. 

For most marine invertebrates that readily consume chemically defended seaweeds, it is not known whether they are actually resistant to, or simply tolerant of, algal secondary metabolites. In the case of specialist consumers (e.g., nudibranchs, ascoglossans, some amphipods or crabs see Section IV.B), a means of resistance to specific chemicals seems likely. However, for marine invertebrates that consume a diverse array of prey that produce different chemical defenses against a broad suite of predators,85,86 perhaps tolerance or less-specific mechanisms of resistance (i.e., gut pH) become more important. The actual mechanisms by which marine consumers avoid harmful effects of consuming chemical defenses (detoxification or dietary mixing) are even less well understood (see Section II.B.2). 

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