Multidisciplinary Studies of the Genus "Cystodytes" (Ascidiacea): From Molecules to Species

摘要: Intraspecies variability is widespread in marine invertebrates. Previous reports of "Cystodytes" (Ascidiacea, Polycitoridae) the Mediterranean have been routinely attributed to nominal species "Cystodytes dellechiajei." In Mediterranean, even though zooid anatomy remarkably uniform, general morphology colonies varies greatly, especially terms color and spicular composition (observed under scanning microscopy). Two different chemotypes, according their alkaloid chemistry, were defined for 4 morphs using both HPLC RNM techniques MALDI-TOF analyses. The purple morph displayed a chemotype based on sulfur-containing pyridoacridines shermilamine B, kuanoniamine D, deacetylated forms: deacetylkuanoniamine D deacetylshermilamine B (new natural product). blue green C9-unsubstituted ascididemin 11-hydroxyascididemin. No major was found brown form. All these alkaloids present tunic zooids, with exception morph, where tunic, whilst forms zooids. Cellular localization compounds ultra structural study blue, attempted by electron microscopy X-ray microanalysis. main cell types identified bladder cells, pigment amebocytes, phagocytes, morula cells. appeared be stored addition, anti-predatory properties crude extracts, acidity, contents assayed forms, Guam (USA), three generalist predators (damselfishes, puffer fishes sea urchins). Toxicity extracts also measured Microtox bioassay. as well ascididemin, toxic significantly deterred fish but not urchin predation. contrast, acidity itself, shape concentration did deter feeding. To determine if observed variation had genetic basis, fragment mithocondrial gene Cytocrome Oxidase I sequenced phylogenetic population analyses performed. results pointed towards existence at least 2 within 67 samples 15 colors analyzed. first well-defined group contained mainly disc-shaped spicules typical genus. second grouped all sphere-shaped addition ones. When partitioned between geographic locations, former component explained most variance. A biological cycles carried out from July 2002 February 2004. Both reproductive growth periods, although partially overlapping, showed significant temporal lags, reinforcing previous chemical indicating that are reproductively isolated represent distinct species. whether there seasonal pattern production physical defenses, sampled year. Ascididemin quantified ash content calculated an estimate defenses. when ascidian invested reproduction, energy allocated other life cycle parameters, such growth, reduced. multidisciplinary approach used genus provided interesting case through which develop better understanding biology, ecology secondary chemistry