Grandidierella khambhatensis, Thacker & Patro & Bhoi & Myers & Kumar & Trivedi, 2025

Grandidierella khambhatensis sp. nov.

Figs. 1B View FIGURE 1 , 6 View FIGURE 6 & 7 View FIGURE 7

Etymology

This species is named after its type locality, the Gulf of Khambhat .

Diagnosis

Male gnathopod 1 basis anterodistal corner produced into a well-developed rounded lobe and propodus posterior margin with two rectangular knobs. Male gnathopod 2 propodus posterior margin convex, smooth and palm oblique. Uropod 3 ramus curved distally.

Type materials

Holotype

India • ♂, 6.0 mm; Dandi , Gujarat; 20°53'29"N, 72°47'36"E; 13 Mar 2024; D R. Thacker leg.; LFSC.ZRC-284. GoogleMaps

Paratypes

India • 1 ♂, 6.0 mm ( LFSC.ZRC-285) , 5 ♀♀, 5.0–6.0 mm; same collection data as for holotype; LFSC.ZRC-287 GoogleMaps .

Ecology type. Collected from tubes made in hard muddy substratum. Salinity 35±2 PSU.

Description. Based on holotype.

HEAD. Eyes small, round.

ANTENNA 1 ( Fig. 6 View FIGURE 6 ). Slender, 1.1 x the length of antenna 2; length ratio of peduncular articles 1–3 1:1.23:0.61; primary flagellum 1.4 × the length of peduncle; accessory flagellum one articulate.

ANTENNA 2 ( Fig. 6 View FIGURE 6 ). Stout, length ratio of peduncular articles 3–5 1:2.28:2.71; flagellum short with 6 articles, article 4 to 6 each with a robust spine.

MAXILLA 1 ( Fig. 6 View FIGURE 6 ). Outer plate with eight apical robust setae, palp article 2 with four apical robust setae.

MAXILLA 2 ( Fig. 6 View FIGURE 6 ). Inner plate apically setose, an oblique setal row present; outer plate apically setose.

MANDIBLE ( Fig. 6 View FIGURE 6 ). Palp 3 articulate, ratio of three articles 1-3 1:2.21:2.46; incisor with 4 cusps, lacinia mobilis with 3 cusps, 5 accessory setae present.

MAXILLIPED ( Fig. 6 View FIGURE 6 ). Inner plate with several plumose setae; outer plate with 5 robust marginal setae and 4 apical thick setae; palp article 2 longest; article 4 with apical nail.

GNATHOPOD 1 ( Fig. 7 View FIGURE 7 ). Basis subrectangular 1.5 x longer than broad with four setae on posterior margin, anterodistal corner produced into a rounded lobe; ischium small, subrectangular, broader than long, posterodistal corner with 2 small setae; merus 1.6 x the length of ischium, posterior margin moderately setose; carpus large, 1.6 x longer than broad, anterior margin almost straight with 2 setae, posterior margin with weak undulations, moderately setose, posterodistal corner produced into a long conical tooth, near to that a small rounded knob; propodus anterior margin convex with several setae, posterior margin almost straight, moderately setose with two rectangular knobs; dactylus long reaching almost 0.7 × length of carpus.

GNATHOPOD 2 ( Fig. 7 View FIGURE 7 ). Basis 4.5 × longer than broad, anterior margin with eleven small setae, posterior margin with four long setae, posterodistal corner with a pair of long setae; merus 1.6 × as ischium, distal margin sparsely setose; carpus 0.7 × the length of basis, both margins densely setose; propodus subrectangular, both margins moderately setose, palm oblique; dactylus slightly longer than palm.

PEREOPOD 3 ( Fig. 7 View FIGURE 7 ). Basis 1.8 × the length of merus, anterior margin with 7 sized setae, posterior margin with six setae; ischium small, subrectangular, posterodistal corner with 3 setae; merus 1.6 × the length of propodus, anterior margin with five setae, posterior margin with three setae, anterodistal and posterodistal corner with four and three setae respectively; carpus 0.8 × the length of propodus, anterior margin with two setae, posterior margin with nine setae, anterodistal corner with one seta; propodus slender, with four setae on anterior margin, six setae on posterior margin, anterodistal corner with a pair of setae; dactylus slender, 0.5 × the length of propodus.

PEREOPOD 4 ( Fig. 7 View FIGURE 7 ). Basis 1.5 × the length of merus, anterior margin with 8 sized setae, posterior margin with four setae, posterodistal corner with two setae; ischium small, subrectangular, posterodistal corner with 3 setae; merus 1.2 × the length of propodus, both margins with four setae on each, anterodistal and posterodistal corner with a pair of setae on each; carpus 0.7 × the length of propodus, anterior margin with two setae, posterior margin with three setae, anterodistal corner with three setae, posterodistal corner with a pair of setae; propodus slender, with three setae on anterior margin, five setae on posterior margin, anterodistal corner with a tuft of 4–5 setae; dactylus slender, 0.5 × the length of propodus.

PEREOPOD 5 ( Fig. 7 View FIGURE 7 ). Shorter than pereopod 4; basis anterior margin with two small setae, posterior margin with ten setae, anterodistal margin with 2 simple and one robust setae; ischium small with a single seta on anterior margin; merus subequal to propodus with 6–7 setae on anterior margin, two setae on posterior margin, anterodistal corner with a tuft of three setae, posterodistal corner with one seta; carpus 0.7 × the length of propodus, three small to medium sized spines on posterior margin, anterodistal corner with two long setae, posterodistal corner with a single seta; propodus anterior margin with five setae, posterior margin with four small to medium sized spines, anterodistal corner with a tuft of setae, posterodistal corner with two thin setae and a single spine; dactylus short, 0.5 × the length of propodus.

PEREOPOD 6 ( Fig. 7 View FIGURE 7 ). 0.8 x the length of pereopod 7; basis subrectangular, anterior margin with seven small setae, posterior margin with two robust setae and sparsely placed setae; ischium longer than broad, anteroventral corner with one thin and one robust seta; merus 1.4 × the length of carpus, anterior margin with few thin setae, posterior margin with two thin and five thick setae, anterodistal corner with a pair of setae, posterodistal corner with one robust seta and two long thick setae; carpus 0.6 × the length of propodus, anterior margin with three setae, posterior margin with four setae, medial surface with four spines, anterodistal corner with three setae, posterodistal corner with two long setae and one spine; propodus subequal to basis, anterior margin with four simple setae and four robust setae, posterior margin with seven setae, posterodistal corner with a tuft of long setae; dactylus 0.4 × the length of propodus.

PEREOPOD 7 ( Fig. 7 View FIGURE 7 ). Basis anterior margin with five small setae, posterior margin sparsely six small robust setae and densely placed long plumose setae; ischium small, with a tuft of three setae on anterodistal corner; merus 2 × the length of carpus, anterior margin with seven setae, posterior margin with five setae, posterodistal corner with two long setae; carpus 0.6 × the length of propodus, anterior margin with four setae, posterior margin with five setae, anterodistal and posterodistal corners with two setae each; propodus subequal to basis, anterior margin with 8–10 small setae, posterior margin with 9–10 long setae, anterodistal corner with two long setae, posterodistal corner with a tuft of long setae; dactylus 0.5 × the length of propodus.

EPIMERA 1–3 ( Fig. 6 View FIGURE 6 ). Ventral margin bare, posteroventral corner of each with a thick seta.

UROPOD 1 ( Fig. 6 View FIGURE 6 ). Peduncle 1.8 × longer than both subequal rami; inter ramus spine very small.

UROPOD 2 ( Fig. 6 View FIGURE 6 ). Peduncle subequal to endopodite; exopodite 0.7 × the length of endopodite.

UROPOD 3 ( Fig. 6 View FIGURE 6 ). Uniramous; ramus curved distally, 1.8 × the length of peduncle.

TELSON ( Fig. 6 View FIGURE 6 ). 0.8 × the length of broad, laterodistal corner each with one long and one short seta.

Female (sexually dimorphic characters).

GNATHOPOD 1 ( Fig. 7 View FIGURE 7 ). Basis subrectangular 2 × longer than broad, posteroventral corner with a tuft of setae; ischium subrectangular; merus 2 × the length of ischium; carpus subtriangular, 0.6 × the length of propodus, anterior margin with few setae, posterior margin moderately setose; propodus oval, both margins sparsely setose, palm with 2 robust setae on the posterior corner and 2 robust setae behind the palm; dactylus subequal to palm.

GNATHOPOD 2 ( Fig. 7 View FIGURE 7 ). Basis 3.8 × longer than broad, anterior margin with several small setae, posterior margin with 3 setae, posterodistal corner with a tuft of 2 setae; ischium small; carpus 2.6 × longer than broad, anterior margin sparsely setose, posterior margin densely setose; propodus oval, 0.9 × the length of carpus, both margins sparsely setose, palm with 2 small robust setae on the posterodistal corner and 2 small seta behind palm; dactylus subequal to palm.

Remarks

Grandidierella khambhatensis sp. nov. described here appears to be very close to G. perlata Schellenberg, 1938 in having the following character states: male gnathopod 1 carpus anterior margin almost straight, posterior margin with undulations; propodus anterior margin convex, posterior margin almost straight with two knobs. However, G. khambhatensis sp. nov. can be differentiated from G. perlata in having following characters: male gnathopod 1 basis anterodistal corner produced into a well-developed rounded lobe ( Fig. 7G View FIGURE 7 1 View FIGURE 1 ) (versus posteroventral lobe not well-developed in G. perlata, Schellenberg (1938) ; Fig. 46a); male gnathopod 1 carpus posterior margin with weak undulations, posterodistal corner tooth with blunt end and no stridulating organs ( Fig. 7G View FIGURE 7 1 View FIGURE 1 ) (versus posterior margin with strong undulations, posterodistal corner tooth with sharp end and presence of stridulating organs in G. perlata, Schellenberg (1938) ; Fig. 46a); male gnathopod 1 propodus posterior margin with two rectangular knobs ( Fig. 7G View FIGURE 7 1 View FIGURE 1 ) (versus knobs more rounded in shape in G. perlata, Schellenberg (1938) ; Fig. 46a); male gnathopod 2 propodus posterior margin convex with smooth ridges and palm oblique ( Fig. 7G View FIGURE 7 2 View FIGURE 2 ) (versus propodus posterior margin straight with crenated ridges and palm straight in G. perlata, Schellenberg (1938) ; Fig. 46b); uropod 3 ramus hook shaped ( Fig. 6U View FIGURE 6 3 View FIGURE 3 ) (versus ramus rod shaped-straight).

Distribution

Currently known only from its type locality, Dandi , Gujarat State, India .