Melita ajmali, Thacker & Myers & Trivedi, 2025

Thacker, Dimple, Myers, Alan A. & Trivedi, Jigneshkumar N., 2025, One new species of Melita Leach, 1814 (Hadzioidea, Melitidae) from Gujarat State, India, Zootaxa 5717 (1), pp. 127-137 : 128-133

Melita ajmali sp. nov.

( Figs. 1–4 )

Type material. Holotype Male, 8.0 mm, ( LFSC.ZRC-292) Zanzmer ( 21°10'59"N 72°04'32"E), 26 March, 2023, coll. D. R. Thacker . Paratype, 10 males, 6.0–8.0 mm; 4 females, 6.0–7.0 mm, ( LFSC.ZRC-293) same data as holotype .

Other Materials. 5 males and 3 females, ( LFSC.ZRC-294) Uncha Kotada ( 21°07'26"N 71°58'24"E) 27 March 2023, coll. D. R. Thacker ; 8 males and 8 females, ( LFSC.ZRC-294) Gopnath ( 21°11'57"N 72°06'40"E) 25 March 2023, coll. D. R. Thacker .

Etymology. This species is named in honour of the eminent carcinologist, the late Professor Syed Ajmal Khan, from the Centre of Advanced Study in Marine Biology, Annamalai University, Tamil Nadu State, India for his enormous contribution in taxonomical studies on crustaceans of India.

Diagnosis: Gnathopod 1 propodus with curved anterodistal projection extending over the dactylus. Gnathopod 2 dactylus inner margin crenulated. Urosomite 2 with 3 dorsolateral robust setae. Pereopod 5–7 basis posterior margin smooth. Uropod 3 inner ramus with 3 apical robust setae.

Description. Based on holotype, male, 8.0 mm, LFSC.ZRC-292.

Head. Cephalic lobes rounded with a shallow notch. Eyes medium sized, subrounded. Antenna 1 peduncular article 0.8x as long as article 2; article 2 2.7x as long as article 3; accessory flagellum with 5 large and 1 rudimentary article. Antenna 2 0.75 x as long as antenna 1; gland cone reaching nearly half of the peduncular article 3; article 4 subequal to article 5. Mandible incisor 4 dentate; lacinia mobilis 2 dentate; accessory setal row with 5 setae; palp 3-articulate, article 2 subequal to article 3. Left maxilla 1 inner plate distal margin rounded with 9 apical plumose setae; outer plate with 9 multi-cuspidate setae; palp 2- articulate, article 2 with 9 robust setae and 10 long setae apically. Right maxilla 1 palp article 2 with 6 robust setae and 6 long setae apically. Maxilla 2 inner plate narrower than outer plate, inner plate with apical and marginal setae; outer plate with apical setae. Mandible molar triturative with a plumose seta; palp 3 articulated, article 2 and 3 subequal; right incisor 4 dentate, lacinia mobilis with 2 large and several small teeth and accessory setal row with 6 multidentate setae; left incisor 5 dentate, lacinia mobilis 4 dentate, and accessory setal row with 9 multidentate setae. Maxilliped inner plate distal margin reaching half of the outer plate; apical and inner sub-margin with plumose setae; palp 4 articulate; article 4 with nail. Labium outer lobes broad with apical and marginal setae; inner lobes indistinct.

Pereon. Gnathopod 1 coxa longer than broad, anterior margin slightly convex; basis anterior margin setose on distal half, posterior margin with few setae proximally, posterodistal corner with a long seta; ischium 1.5x longer than broad; merus posterior margin with multiple small robust setae in a row and few long simple setae; carpus 0.9x as long as basis, anterior margin bare, posterior margin densely setose; propodus 0.6x as long as carpus, subovate, anterior margin convex, moderately setose, curved anterodistal projection extending over the dactylus, posterior margin straight, moderately setose, palm with a rounded mid-palmar tooth, posterodistal corner produced with apical tuft of setae; dactylus as long as palm, with several small setae apically and 1 on upper margin.

Gnathopod 2 coxa subrectangular, 1.7x as long as broad; basis slender, 2.8x as long as broad, anterior margin with few setae distally, posterior margin with 4 setae, posterodistal corner with 1 seta; ischium 1.4x as long as broad; merus 1.3x as long as ischium; carpus compressed, 0.9x as long as broad, anterodistal corner with 1 thick seta, posterior margin densely setose; propodus subovate, 1.8x as long as broad, both margins with several tufts of short to medium setae, palm oblique, densely setose; dactylus closing across medial surface of propodus, longer than palm, posterior margin crenulated.

Pereopod 3 coxa subrectangular, 1.9x as long as broad; basis slender 4.7x as long as broad, anterior margin with 1 long as 4 small setae, anterodistal margin with a tuft of 2 long setae, posterior margin with 3 setae and posterodistal corner with one seta; merus anterior margin with 3 setae, anterodistal corner with a tuft of 2 setae, posterior margin with 5 setae, posterodistal corner with a tuft of simple setae; carpus 0.7x as long as merus, propodus subequal to carpus, dactylus one third of the propodus, inner margin with 1 small seta.

Pereopod 4 coxa 1.2x as long as broad, posterior margin excavate; basis slender, 1.33x as long as broad, anterior margin bare, posterior margin with few setae; merus anterior margin with 3 setae, anterodistal corner with a tuft of 2 setae, posterior margin with 2 small setae, posterodistal corner with a tuft of 2 setae; carpus 0.8x as long as merus, propodus subequal to carpus; dactylus 0.4x as long as propodus, inner margin with 1 small seta.

Pereopod 5 coxa 0.4x as long as basis; basis 1.3x as long as broad, anterior margin with 7 small setae, posterior margin weakly crenulate; ischium small; merus 0.6x as long as basis; carpus 0.7x as long as merus; propodus subequal to merus; dactylus small, 0.2x as long as propodus with 1 small seta on the inner margin.

Pereopod 6 coxa smaller than coxa 5, 0.3x as long as basis; basis 1.4x as long as broad, anterior margin with 11 small setae, posterior margin weakly crenulate; merus 0.6x as long as basis; carpus 0.8x as long as merus; propodus 1.2x as long as merus; dactylus 0.2x as long as propodus with 1 small seta on the inner margin.

Pereopod 7 similar to pereopod 6.

Pleon. Pleonites 1–3 without dorsal spines or robust setae. Epimera 1–3 with anteroventral corner rounded and posteroventral corner subquadrate. Epimeron 1 ventral margin bare, posteroventral corner with a small acute tooth. Epimeron 2 ventral margin with 3 small robust setae, posteroventral corner with a small acute tooth. Epimeron 3 vetral margin with 3 small robust setae, posteroventral corner acutely produced. Urosomites 1–3 lacking dorsal spines. Urosomite 2 with 3 dorsolateral robust setae. Uropod 1 peduncle 1.2x as long as rami, 1 small basofacial seta; both rami subequal. Uropod 2 peduncle subequal to outer ramus; inner ramus 1.4x as long as outer ramus. Uropod 3 peduncle 0.4x as long as outer ramus; rami distally truncated; outer ramus 1-articulate, 6.7x as long as inner ramus, with 3 terminal robust setae. Telson 1.1x as long as broad, entirely cleft, lobes distally acute, each lobe with 4 subdistal robust setae, 2 robust setae on inner margin, 2 robust setae on outer margin and 2 dorsal robust setae.

Female (sexually dimorphic characters only). Based on paratype female, 7.0 mm, LFSC.ZRC-293. Gnathopod 1 coxa 1.5x as long as broad; basis 3.3x as long as broad; merus posterior margin with a row of several small robust setae and few long simple setae; carpus posterior margin with several tufts of small setae; propodus sparsely setose on both margins; dactylus subequal in length to palm. Gnathopod 2 coxa 1.9x as long as broad; basis both margins sparsely setose; carpus comparatively longer than in male; propodus with 2 posterodistal robust setae; dactylus as long as palm. Pereopod 6 coxa anterior lobe completely curved posteriorly.

Remarks. Krapp-Schickel & Sket (2015) divided species of Melita into four groups. These groups were established only for the understanding and the ease of comparison. These groups were named as A1, A2, B1 and B2 depending on the presence or absence of dorsal spines and robust setae on pleonites and urosomites, and the number of articles in uropod 3 outer ramus. Melita ajmali sp. nov. would be placed in group B1 as it has characters such as: absence of spines on pleonites and urosomites, urosomite 2 with dorsal robust setae and uropod 3 outer ramus 1- articulate. Within the group B1 Melita ajmali sp. nov. is very close to Melita persia Momtazi, Sari & Maghsoudlou, 2014 , in having: weakly setose antenna 2, maxilla 1 inner plate with 9 plumose setae and outer plate with 9 multi-cuspidate setae; mandibular palp article 3 setose apically and along both inner and outer margins; mandibular palp articles 2 and 3 subequal in length; epimeral plate 3 with 3 ventral setae and urosomite 2 with 3 robust setae on each side and female coxa 6 anterior lobe completely curved posteriorly.

However, Melita ajmali sp. nov. can be differentiated from M. persia by the smooth posterior margin of the basis of pereopods 5, 6 and 7 and of epimeral plate 3 ( Fig. 3 , P5–P7 & Fig. 2 , Ep3). These are all distinctly serrate in M. Persia ( Momtazi et al. 2014: fig. 3, ep3 & fig. 7, P5–P7). The material described by Momtazi et al. (2014) has a maximum size of 6.4 mm whereas material of Melita ajmali sp. nov. figured here is 8.0 mm. However, no serrations were present in smaller specimens of Melita ajmali sp. nov. of a size comparable to those figured by Momtazi et al. (2014). In addition, the accessory flagellum of antenna 1of Melita ajmali sp. nov. is composed of 5 long and 1 rudimentary articles ( Fig. 2 , A 1 ), while 3–4 articles in M. persia ( Momtazi et al. 2014, fig. 5) and uropod 3 inner ramus has 3 apical robust setae in Melita ajmali sp. nov. ( Fig. 4 , U 3 ), whereas there are 2 apical robust setae in M. Persia ( Momtazi et al. 2014, fig. 5, U3).

Discussion. In addition to M. ajmali sp. nov., two other species of the genus, M. orgasmos and M. zeylanica, have been confirmed from India. Melita orgasmos was reported from Kilakkarai, Tamil Nadu, by Sivaprakasam (1966). Similarly, M. zeylanica was reported from Pamban and Kilakkarai, Tamil Nadu, by Sivaprakasam (1966). Two additional species, M. inaequistylis and M. nitida , have been previously reported from Indian waters; however, their records remain unconfirmed. Melita inaequistylis , reported from Chilika Lake, Odisha, by Chilton (1921), lacks illustrations and is inadequately described. Melita nitida is mentioned only in the checklist by Surya Rao (1972) without any verified specimen examination. Therefore, the records of these species remain uncertain from Indian waters. With the addition of M. ajmali sp. nov., the total number of valid Melita species globally rises to 65

Figures

FIGURE 1. Melita ajmali sp. nov. male, paratype (LFSC.ZRC-293): 8.0 mm, Zanzmer (21°10'59"N 72°04'32"E), Gujarat, India. Scale bar represents 1.0 mm.

FIGURE 2. Melita ajmali sp. nov. male, holotype (LFSC.ZRC-292): 8.0 mm, Zanzmer (21°10’59”N 72°04’32”E), Gujarat, India. Scale bars represent 0.25 mm.

FIGURE 3. Melita ajmali sp. nov. male, holotype (LFSC.ZRC-292): 8.0 mm, Zanzmer (21°10’59”N 72°04’32”E), Gujarat, India. Scale bars represent 0.25 mm.

FIGURE 4. Melita ajmali sp. nov. male, holotype (LFSC.ZRC-292): 8.0 mm; paratype female (LFSC.ZRC-293): 7.0 mm, Zanzmer (21°10’59”N 72°04’32”E), Gujarat, India. Scale bars represent 0.25 mm.