New species of Tridentella Richardson, 1905 (Isopoda: Cymothoida: Tridentellidae), tropical marine isopod crustaceans from the Banda Sea, Indonesia

Abstract

Tridentella memikat sp. nov., Tridentella tanimbar sp. nov. and Tridentella brandtae sp. nov. are described and figured. T. memikat sp. nov. is the largest species in the family and can be identified by the broadly rounded pleotelson posterior margin, complete lack of dorsal ornamentation and antennule peduncle articles 2 and 3 each with the posterodistal angle produced. T. tanimbar sp. nov. is a sister species to T. recava Bowman, 1986, both species characterised by a flattened body shape, lack of dorsal ornamentation and deep excision to the pleotelson apex; T. tanimbar sp. nov. is identified by free lateral margins to pleonite 5, antennal flagellum extending to pereonite 5 or 6, pleon wider than pereon, the propodus of pereopods 1–3 lacking long slender robust setae, uropod exopod shorter (0.8) than endopod and the uropods not extending beyond the pleotelson. Tridentella brandtae sp. nov. is characterised by the posterior margin of the pleotelson being subtruncate and weakly emarginate; posterior margins of pereonites 6 and 7, pleonites 3–5 and the dorsal surface of the pleotelson weakly nodulose; inferior margins of the propodus of pereopods 2 and 3 with a double row of robust setae; the shape and setation of the uropods; adult males are further characterised by the presence of a large bluntly rounded robust seta at the inferodistal angle of the carpus. These species constitute the first record of the family from the Indian Ocean.