Predator deterrence

Vervoort HC, Richards-Gross SE, Fenical W, Lee AY, Clardy J (1997) Didemnimides A-D Novel, Predator-Deterrent Alkaloids from the Caribbean Mangrove Ascidian Didemnum conchyliatum. J Org Chem 62 1486... 

Vervoort, H. C., Richards-Gross, S. E., Fenical, W., Lee, A. Y., and Clardy, J. C., Didemnimides A-D novel, predator-deterrent alkaloids from the Caribbean mangrove ascidian Didemnum conchyliatum, J. Org. Chem., 62, 1486, 1997. 

Stachowicz, J.J. and Lindquist, N., Chemical defense among hydroids on pelagic Sargassum predator deterrence and absorption of solar UV radiation by secondary metabolites, Mar. Ecol. Prog. Ser., 155, 115, 1997. 

The predator deterrent effects of Gorgonia ventalina and its nudibranch predator Tritonia hamnerorum are described in Section 4.12.8.3. 

Vervoort et al.115 next isolated and characterized a novel cyclized didemnimide alkaloid from the Caribbean Ascidian Didemnum conchyliatum. In prior work, the primary author and colleagues isolated and identified four novel alkaloids possessing unprecedented indole- maleimide imida/ole carbon frameworks, which ecological testing suggested served in a predator-deterrent role for the organism. Further fractionation led to a small quantity of a deep purple minor metabolite that required the use of micro-probe technology to facilitate its characterization. The molecule was shown to be related to the previously characterized molecules via cyclization to afford (52). 

Mathis, A., Chivers, D.P. R.J.F Smith. 1995. Chemical alarm signals predator-deterrents or predator attractants Am. Nat., 145, 994-1005. 

Since Williams (1964) proposed that the alarm substance acts as a predator deterrent, there has been one direct test of his hypothesis. Bernstein and Smith (1983) treated fathead minnows (Pimephales promelas) with androgen, a process that eliminates ASCs from the skin (Smith, 1973). They then observed the feeding behavior of rainbow trout presented with androgen-treated minnows without ASCs and untreated control minnows with ASCs. The trout showed no significant preference for either type of minnow even though the same test procedure did detect a preference for liver over commercial food pellets. The results indicate that the presence of ASCs in the skin does not act as a deterrent to rainbow trout. This is consistent with the widespread use of minnows, including fathead minnows, as bait fish by sports fishermen. 

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