Demaorchestia alanensis Bhoi & Tarafdar & Patro 2023, sp. nov.
Creators: name: Bhoi, Gitanjali
name: Tarafdar, Lipika
name: Patro, Shesdev
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Talitridae
Demaorchestia
Demaorchestia alanensis

description: Demaorchestia alanensis Bhoi & Patro sp. nov.
Figs. 1–6
Material Examined. Holotype: Male, 12 mm (ZSI/ EBRC /Cr15006), shoreline of Chilika Lagoon, Barkul (21°52'34.97"N, 87°58'58.75"E), Odisha, India, from sandy beach, 22/01/2023, coll. Gitanjali Bhoi and Lipika Tarafdar.
Paratypes: ZSI/ EBRC /Cr15007, 1 male, 12.5 mm; ZSI/ EBRC /Cr15008, 1 male, 15 mm; ZSI/ EBRC /Cr15009, 1 female, 12.5 mm; ZSI/ EBRC /Cr15010, 1 female, 12 mm. Same data as holotype.
Ecology type: Sand-hopper
Etymology: The species named after the amphipod taxonomist Professor Alan Myers, who is a renowned person in amphipod studies.
Diagnosis: Propodus of gnathopod 1 with two to three groups of setae in anterior margin. Epimera strongly serrated on all plates. Distal end of dactylus of gnathopod 2 is blunt.
Description: Based on male holotype, 12 mm.
Head. Eyes medium round. Antennae 1 long, reaching end of peduncular article 4 of antennae 2; flagellum with five articles. Antennae 2 peduncular articles incrassate; peduncular articles 4 and 5 subequal and article 3 shorter than them, and article 2 smallest; flagellum 15-articulated. Maxilla 1 palp 1-articulated, inner plate with two plumose setae on apex, and outer plate with nine strong medially serrated robust setae. Maxilla 2 inner plate lateral margin with stout plumose seta, outer plate with small setae on lateral margin and elongate setae on apex. Mandible palp absent, left lacinia mobilis 5-cuspidate and incisor 5-dented. Maxilliped palp broad, article 2 with distomedial lobe, article 4 reduced, button shaped. Lower lip with narrow lobes and small setae covered with apex.
Pereon. Gnathopod 1 subchelate, posterodistal margin of carpus and propodus having lobe with palmate setae, palm transverse, anterior margin of propodus with two or three groups of robust setae, dactylus slightly shorter than palm, simplidactylate. Gnathopod 2 subchelate, coxa as long as broad, basis long and broad, carpus triangular, propodus broad and anterior margin convex, palm acute, round distally, irregular or sigmoidal, with small mid palmar sinus, without large sinus distally, dactylus not modified distally, blunt, slightly shorter than palm. Pereopod 3–7 dactyli cuspidactylate. Pereopod 3 longer than pereopod 4, cuspidactylate. Pereopod 5, pereopod 6 and pereopod 7 in increasing order. Pereopod 4 significantly shorter than pereopod 3, dactylus amplidactylate, thickened proximally with notch midway along posterior margin or short with mini wavy posterior margin. Pereopod 6 1.5× times shorter than pereopod 7, merus and carpus of male expanded. Pereopod 7 not incrassate, basis moderately expanded, posterior margin having minute serration with small setae, robust setae present in the middle row of carpus and propodus, propodus without large distal tuft setae.
Pleon. All pleopods well developed. Epimera strongly serrated on all plates. Uropod 1 distolateral setae absent, peduncle longer than rami, 12 robust setae present on the two rows of peduncle, endopod with double row of setae, seven marginal setae present on both rows and exopod without any marginal setae. Uropod 2 peduncle having seven robust setae in double rows, exopod having single row of marginal setae and endopod with two rows of setae. Uropod 3 ramus shorter than peduncle (1.5× times the ramus), rami having bifid setae on apical and marginal rows and one on peduncle with two other setae. Telson apically incised with eight setae on each lobe.
Female. (Sexually dimorphic characters) Gnathopod 1 parachelate, with small lobe on posterior margin of propodus, dactylus longer than palm. Gnathopod 2 mitten shaped, bifid setae present in all segments, palmate setae present on posterior margin of merus, carpus and propodus. Pereopod 7 middle row spine absent in carpus and propodus. Oostegite with simple smooth tip.
description: Published as part of Bhoi, Gitanjali, Tarafdar, Lipika & Patro, Shesdev, 2023, A new species of amphipod of the genus Demaorchestia Lowry & Myers, 2022 (Senticaudata, Talitridae) from Chilika Lagoon, east coast of India, pp. 216-224 in Zootaxa 5383 (2) on pages 217-222, DOI: 10.11646/zootaxa.5383.2.6, http://zenodo.org/record/10350867