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| Actinimenes koyas Paramasivam, Dhinakaran, Kumar & Lal, 2022 |
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.
Keywords: Actinimenes koyas sp. nov.; anemone associated fauna; Arabian Sea; Lakshadweep; morphology; phylogenetic tree
SYSTEMATICS
Order Decapoda Latreille, 1802
Infraorder Caridea Dana, 1852
Superfamily Palaemonoidea Rafinesque, 1815
Family Palaemonidae Rafinesque, 1815
Genus Actinimenes Ďuriš and Horká, 2017
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| Actinimenes koyas sp. nov. from Agatti island, India. (a) Holotype: ovigerous female (CL 3.5 mm, NBFGR/PALAKOY─01); (b) paratype, male (CL 3.2 mm, NBFGR: DBTLDA62, Ethanol preserved). |
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| Collection site, assemblages of Heteractis magnifica at Agatti Island, Lakshadweep, India with live coloration of Actinimenes koyas sp. nov. (Depth 1-2 m). |
Actinimenes koyas sp. nov.
Etymology. Koyas are an important ethnic community of Lakshadweep. Koyas have made a significant contribution to the development and preservation of the heritage of the society at Lakshadweep. The present species is named “Koyas” to honor the local community at Lakshadweep.
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| Map showing (a-d) location of Agatti Island, Lakshadweep, India, the type locality of Actinimenes koyas sp. nov. |
CONCLUSION:
A new symbiotic species from the palaemonid shrimp genus Actinimenes is described and illustrated from Lakshadweep, India. Actinimenes koyas sp. nov. was obtained from the magnificent sea anemone Heteractis magnifica (Actiniaria). Sea anemone-associated species of the genus Actinimenes are widely distributed in the tropical regions of the Indo-West Pacific, and A. koyas sp. nov. is reported for the first time from the Arabian Sea. Additionally, molecular information from mitochondrial markers (COI and 16S) are provided and the ML tree suggests that A. koyas sp. nov. is sister to a clade of A. inornatus.
Purushothaman Paramasivam, A. Dhinakaran, T. T. Ajith Kumar and Kuldeep K. Lal. 2022. A New Species of the Genus Actinimenes Ďuriš and Horká, 2017 (Crustacea: Decapoda: Palaemonidae) from the Arabian Sea, Lakshadweep Islands, India. Nauplius. 30. DOI: 10.1590/2358-2936e2022008
