ABSTRACT
Around Laing Island (Bismarck Sea), juveniles of the fishAbudefduf leucogaster are associated with the alcyonarianLitophyton viridis which, on mechanical stimulation, can release a potent ichthyotoxin and appears to be accordingly disliked by large predators. The fish has no special immunity to high levels of toxin but is affected more slowly than others. This has been interpreted in terms of an original strategy wherebyA. leucogaster plays its long reaction time against the diffusion of the toxin, allowing the fish to remain around the soft coral and benefit from indirect chemical protection. Possible biological implications of the toxin release are discussed.
ABSTRACT
Mass-analyzed ion kinetic energy spectrometry (MIKE) is shown to be an efficient and rapid method for the analysis of complex sterol mixtures. The method has been applied to the study of the free sterol fractions of five marine and one freshwater invertebrates.
Subject(s)
Cnidaria/analysis , Porifera/analysis , Sterols/analysis , Animals , Mass Spectrometry/methodsABSTRACT
Allo-aromadendrene, (-)viridiflorol and (+)ledol have been identified as minor constituents of the soft coral Cespitularia aff. subviridis.
Subject(s)
Cnidaria/analysis , Sesquiterpenes/analysis , AnimalsABSTRACT
The structure of 24-methylenecholest-5-en-3beta,7beta,19-triol (II) isolated from the soft coral Litophyton viridis, has been established by X-ray diffraction analysis. The compound is accompanied by its 7-monoacetate derivative.
Subject(s)
Cholestenes/analysis , Cnidaria/analysis , Sterols/analysis , Animals , Gas Chromatography-Mass Spectrometry , Molecular Conformation , Spectrophotometry, Infrared , X-Ray DiffractionABSTRACT
Lobosterol [(24S)-24-methylcholestane-3beta,4beta,5beta,25-tetrol-6-one 25 monoacetate] has been isolated from the Alcyonacean Lobophytum pauciflorum. The structural elucidation of this novel polyoxygenated sterol was achieved by chemical and spectroscopic evidence, and by X-ray diffraction analysis.
