FOUR NEW SPECIES OF TAMBJA BURN, 1962 (NUDIBRANCHIA: POLYCERIDAE) FROM THE INDO-PACIFIC

Abstract

The genus Tambja previously included 24 described species. Four new species, T. tentaculata n. sp., T. gabrielae n. sp., T. zulu n. sp. and Tambja victoriae n. sp., from the Indo-Pacific are described. Tambja tentaculata n. sp., from Guam, is the only known species in the genus with well developed, dorsolaterally grooved, oral tentacles. Its inner lateral teeth have a bifid inner cusp with two long, sharp denticles. The oral tentacles of T. tentaculata are more typical of Roboastra species, while the shape of the inner lateral teeth is more typical of Tambja. Nevertheless, the arrangement of the two cusps of the inner lateral teeth and the presence of a rachidian tooth without denticles and with a central notch at the anterior edge, typical of the species of the genus Tambja, suggest the placement within this genus. Tambja gabrielae n. sp., from Indonesia and Papua New Guinea, has dark green to dark brown ground colour with bright yellow patches scattered on the body. Tambja zulu n. sp. from Durban, South Africa, is characterized by a black ground colour with slender yellow longitudinal lines. Tambja victoriae n. sp. is a new species from Papua New Guinea and Australia that has frequently been misidentified as Roboastra arika, characterized by its blue body colour and yellow lines. The four species are distinguishable based on differences in body coloration, of characters of the radula and of the reproductive system. An overview on distinguishing features of all known Indo-Pacific Tambja species is presented.