Maera gujaratensis, Thacker & Myers & Trivedi, 2024

Thacker, Dimple, Myers, Alan A. & Trivedi, Jigneshkumar N., 2024, On a small collection of Maeridae Krapp-Schickel, 2008 (Crustacea: Amphipoda) from Gujarat, India, Zootaxa 5474 (5), pp. 563-583 : 574-577

Maera gujaratensis sp. nov.

( Figs 1C , 9–11 )

Type material. Holotype male, 8 mm, ( LFSC.ZRC-209) Gopnath (22.1985 N 72.1082 E), 25 March, 2023, coll. D. R. Thacker . Paratype, 4 females, 6–8 mm, ( LFSC.ZRC-210) same data as holotype . Paratypes 3 males, 6–7 mm, ( LFSC.ZRC-210) same data as holotype .

Other material. 3 males, 7–9 mm and 3 females, 6–7 mm ( LFSC.ZRC-211) Zanzmer (21.1830 N 72.0764 E), 26 March, 2023, coll. D. R. Thacker ; 4 males, 6–8 mm and 1 female, 6 mm ( LFSC.ZRC-211) Uncha Kotda (22.1223 N 71.9707 E), 27 March, 2023, coll. D. R. Thacker ; 2 males, 6 & 7 mm and 1 female, 6.5 mm ( LFSC.ZRC-211) Shivrajpur (22.3312 N 68.9496 E), 27 February, 2022, coll. D. R. Thacker .

Etymology. A species is named after Gujarat state, India where the type locality of the new species is located. The name is used as a noun in apposition.

Description. Based on holotype, male, 8 mm.

Head. Eyes large, ovate. Antenna 1 longer than antenna 2; peduncular article 1 0.86 times as long as article 2, article 3 0.41 times as long as of article 2; accessory flagellum 6-articulate (fig. 9, A1). Antenna 2 0.63 times as long as antenna 1, peduncular article 4 1.31 times as long as article 5; flagellum 9-articulate. Mandible incisor bearing 2 cusps, lacinia mobilis 4-dentate (fig. 9, A2). Maxilla 1 inner plate bullet shaped with 4 long plumose setae on distal margin; outer plate with 7 apical robust setae; palp article 2 distally setose (fig. 9, Mx1). Labrum distal margin rounded (fig. 9, Lb). Labium distal margin of inner and outer lobes strongly setose (fig. 9, L). Maxilliped inner plate apically setose; outer plate with several long to small robust setae on distal margin and inner margin; palp 4 articulate, article 4 with a long apical robust seta (fig. 9, Mxp).

Pereon. Gnathopod 1 coxa anteroventral corner subquadrate; basis subequal to carpus, both margins setose; merus subrectangular; carpus anterodistal corner produced, posterior margin densely setose; propodus 0.88 times as long as carpus, subovoidal, anterior margin with a row of setae, posterior margin sparsely setose; palm convex with few small setae and two long setae, palmar corner with few long setae; dactylus subequal to palm (fig. 10, G1). Gnathopod 2 coxa subquadrate; basis 0.70 times as long as propodus, both margins few setae, posterior margin with one long seta; merus with acute posterodistal spine; carpus subtriangular; propodus enlarged, subrectangular, palm transverse with a small V-shaped excavation and several small to medium spines, posterodistal corner defined by a triangular tooth and a robust seta; dactylus a little shorter than palm inner margin with several setae on outer margin (fig. 10, G2).

Pereopod 3 longer than pereopod 4; coxa subquadrate, basis anterior margin with a row of small setae, posterior margin with small and medium setae; merus 1.18 times longer than carpus, with 3 robust setae on anterior margin, posterior margin with 2 small setae; carpus anterior margin bare, posterior margin lined 4 setae; propodus 0.84 times as long as carpus, anterior margin bare, posterior margin with 3 robust setae and 4 simple setae, dactylus 0.45 times as long as propodus (fig. 9, P3). Pereopod 4 almost similar to pereopod 3 except propodus 0.92 times as long as carpus (fig. 10, P4).

Pereopod 5 basis subrectangular with posterodistal corner produced; merus 1.64 times as long as carpus with 2 robust setae on posterior margin and 2 tufts and a single seta on the anterior margin; carpus 0.75 times as long as propodus, 3 tufts of setae on anterior margin, posterior margin bare; propodus anterior margin with a row of robust setae, posterior margin bare; dactylus bifid, 0.34 times as long as propodus (fig. 10, P5). Pereopod 6 basis subrectangular, both margins with small setae, posterodistal corner produced; merus 1.55 times longer than carpus, both margins setose; carpus 0.79 times as long as propodus, anterior margin with 2 tufts of long setae, posterior margin bare; propodus anterior margin with 4 pair of robust setae, posterior margin with a single seta; dactylus 0.36 times as long as propodus (fig. 10, P6). Pereopod 7 similar to pereopod 6 (fig. 10, P7).

Pleon. Epimea 1–3 projected posteroventrally. Uropod 1 peduncle 1.24 times as long as inner ramus, with well-developed basofacial seta and long spur at distal margin; outer ramus 0.94 times longer than inner ramus (fig. 11, U1). Uropod 2 peduncle 0.92 times as long as outer ramus; inner ramus subequal to outer ramus (fig. 11, U2). Uropod 3 peduncle 0.62 times as long as outer ramus; inner ramus subequal to outer ramus (fig. 11, U3). Telson deeply cleft, 1.31 times longer than wide, tips of both lobes incised, each lobe with 1 robust seta on outer margin, 2 distal small robust setae and a small seta on inner corner (fig. 11, T).

Female. No sexual dimorphism.

Geographical distribution. The species is so far known only from its type locality, Gopanath and other coastal regions of Gujarat including Shivrajpur, Uncha Kotda and Zanzmer .

Remarks. Maera gujaratensis sp. nov is very close to congener M. hirondellei Chevreux, 1900 in having a V-shaped excavation on male G2 propodus palm. But it can be differentiated from this congener in number of following characters ( Table 1 ).

Figures

FIGURE 1. (A) Ceradocus (Denticeradocus) alama Myers & Nithyanandan, 2016 male, (LFSC.ZRC-214): 10 mm, Shivrajpur; (B) Ceradomaera plumosa Ledoyer, 1973, male (LFSC.ZRC-215): 10 mm, Zanzmer; (C) Maera gujaratensis sp. nov., male paratype, (LFSC.ZRC-210): 7 mm, Gopnath; (D) Quadrimaera okha sp. nov., male paratype, (LFSC.ZRC-213): 4.5 mm, Shivrajpur, Gujarat, India.

FIGURE 9. Maera gujaratensis sp. nov., male holotype (LFSC.ZRC-209): 8 mm, Gopnath (22.1985 N 72.1082 E), Gujarat, India.

FIGURE 10. Maera gujaratensis sp. nov., male holotype (LFSC.ZRC-209): 8 mm, Gopnath (22.1985 N 72.1082 E), Gujarat, India.

FIGURE 11. Maera gujaratensis sp. nov., male holotype (LFSC.ZRC-209): 8 mm, Gopnath (22.1985 N 72.1082 E), Gujarat, India.