Trididemnum species

Larvae of the tunicate Trididemnum solidum are most likely protected by didemnins like 44-46, cyclic depsipeptides that were initially identified from adults of this species [92]. The larvae are highly unpalatable to the wrasse Thalassoma bifasciatum, which rejected the larvae while readily consuming krill eyes that served as larval mimics. Coating one krill eye with the lipid soluble compounds from a single T. solidum larva rendered it as unpalatable as the larvae themselves. Reduced feeding was also observed when didemnin B (45) and nor-didemnin B (46) were administered to reef fishes in the field (Scheme 12) [92]. 

Remember that this species, which can be regarded as fixed, was discovered through the symbiotic relationship that it maintains with ascidians of the family Didemnidae, in particular Diplosoma similis and D. virens, Lissoclinum patella and I. voeltzkowi, Trididemnum cyclops and, more recentiy, the genus Polysyncraton (Duclaux, Lafargue, and Wahl, 1998). These relations have considerable importance insofar as the Didemnidae frequently contain antiviral and antitumor substances whose true origin is probably Prochloron. In our current state of knowledge, it has not yet been possible to cultivate in vitro-isolated... 

This expedition of 1978 was mentioned in Chapter 4. The species Trididemnum cyanophorum and T. solidum were harvested in several areas of the Caribbean Belize, Colombia, Guadeloupe, Honduras, Mexico, and Panama. They are characterized by the presence of a new species of symbiotic cyanobacterium, Synechocystis trididemni. 

Since 1985, a series of 2 -desoxyribonucleosides has been characterized in the species Trididemnum cereum harvested at Banyuls-sur-mer (Mediterranean Sea). This discovery is noteworthy because this category of nucleoside is particularly rare among marine organisms 2 -deoxythymidine and 2 -deoxyuridine might be the only other known examples that have been identified in the crown-of thorns starfish, Acanthaster planci (Komori et al, 1980 Dematte et al, 1985). Figure 28.18 includes 2 -desoxynucleosides of Trididemnum cereum. 

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