J. Lucas Cervera

A new cytotoxic tambjamine alkaloid from the Azorean nudibranch Tambja ceutae

The chemical investigation of Azorean nudibranch mollusk Tambja ceutae led us to isolate a new member of the tambjamine family, tambjamine K (1). The bryozoan Bugula dentata, prey of the nudibranch, was also analyzed and found to contain compound 1 in very small amounts together with known blue pigment 2 and tambjamines A (3) and B (4). The structure of tambjamine 1 was elucidated by the interpretation of the spectroscopic data as well as by the comparison with related compounds. Compounds 1 and 2 possess antiproliferative activity, in particular, tambjamine K (1) displayed high cytotoxicity against both tumor and non-tumor mammalian cells.

A new species of Tambja (Nudibranchia: Polyceridae: Nembrothinae) from southern Brazil

A new species of the genus Tambja Burn, 1962 is described from the western Atlantic on the coast of Brazil. To date, the genus Tambja was represented in the Atlantic Ocean by nine species but only three of them have been recorded from the western Atlantic: T. gratiosa from the Gulf of Mexico, T. divae from Brazil and T. oliva from the Caribbean coast of the Isthmus of Panama. Tambja stegosauriformis sp. nov. is easily distinguished from all its congeneric Atlantic species of the genus by having very well developed light blue tubercles scattered on the yellowish-orange ground with an elongate crest behind the gill until the end of the tail. The anterior margin of the notum is very wide and elevated and it extends into a kind of lapel around the rhinophores. This peculiar external morphology and its conspicuous coloration characterize this species.

Taxonomic revision and phylogenetic analysis of the genus Tambja Burn, 1962 (Mollusca, Nudibranchia, Polyceridae)

This paper discusses the systematics and phylogeny of the genus Tambja Burn, 1962 throughout tropical and temperate areas in the Atlantic, eastern Pacific and Indo‐Pacific. The phylogenetic relationships within Tambja are unknown and a comprehensive taxonomic revision is necessary in order to construct a phylogeny of the genus. To date, Tambja comprises 28 nominal species, 22 of which have been examined morphologically based on newly collected and type material. The reproductive systems of four species (T. limaciformis (Eliot, 1908), T. sagamiana (Baba, 1955), T. amakusana, Baba, 1987 and T. olivaria, Yonow, 1993) were studied for the first time and two species previously considered as valid, Tambja morosa (Bergh, 1877) and Tambja kushimotoensis Baba, 1987, are here synonymized. Of the remaining six nominal species, no additional material has been found since their original description. The holotypes of three (T. diaphana (Bergh, 1877), T. gratiosa (Bergh, 1890) and T. marbellensis Schick & Cervera, 1998) have been re‐examined and the original descriptions improved. Tambja diaphana is regarded as nomen dubium. Tambja amitina (Eliot, 1905), T. divae (Marcus, 1958) and T. anayana Ortea, 1989 remain as valid species until further comparison with new specimens can be made. New structures are also described for several taxa. Morphological and anatomical data from 22 nominal Tambja species have been used to construct a phylogeny. The phylogenetic analysis rejects the monophyly of Tambja and shows its preliminary relationships within the subfamily Nembrothinae.