Abstract A new species, Actinimenes koyas sp. nov. (Decapoda: Palaemonidae) was collected at a depth of 1.0-2.0 m from the coral atoll of Agatti Island, Lakshadweep, Arabian Sea. The species was associated with the sea anemone, Heteractis magnifica (Quoy and Gaimard, 1833). It is the second representative of the genus Actinimenes Ďuriš and Horká, 2017 described from the Arabian Sea. Actinimenes koyas sp. nov. is closely related to A. ornatellus in terms of morphological traits. Actinimenes koyas sp. nov. is distinguished from Actinimenes ornatellus (Bruce, 1979) by the presence of a biramous outer antennular flagellum with three proximal segments fused, a shorter free ramus consisting of 7 to 8 segments with 12-14 groups of aesthetascs, a fourth thoracic sternite with V-shaped median incision and features of the telson and third maxilliped. The present new species is easily distinguished from the other three described species in the genus Actinimenes by the structural variation in the fourth sternal plate with a median notch. Additionally, a phylogenetic analysis inferred by Maximum Likelihood using the mitochondrial genes COI and 16S rRNA shows a close relationship of Actinimenes koyas sp. nov. with Actinimenes inornatus (Kemp, 1922). Pairwise genetic distances estimated using the COI and 16S data provided divergences between A. koyas sp. nov. and other congeneric species.

Abstract The present study reports two new distributional records of palaemonid shrimp, Palaemonella tenuipes Dana, 1852, and P. rotumana (Borradaile, 1898) from the Lakshadweep region, Arabian Sea. The study provides detailed information on, and insight into, diagnostic characters, distinctiveness, and illustrations of both species. The individuals of P. tenuipes were collected from a depth of about 0.5 m in shallow barren pools on rocky flats near the shore, while a specimen of P. rotumana was collected from a dead coral patch at a depth of 1-2 m. The intraspecific genetic divergences were estimated for both species using COI and 16S sequence data.