Tirmilyra concinnus ( Ghani & Tirmizi, 1995 ), 2023

Patel, Krupal, Naderloo, Reza, Trivedi, Jigneshkumar & Mitra, Santanu, 2023, On the taxonomy of Philyra sagittifera (Alcock, 1896) and P. concinnus Ghani & Tirmizi, 1995 (Decapoda, Brachyura, Leucosiidae), with description of a new genus from the Indian Ocean, Zootaxa 5330 (3), pp. 430-440 : 436-439

Tirmilyra concinnus ( Ghani & Tirmizi, 1995) n. comb.

( Figs. 1E, F , 2C, D , 3C, D , 4E, F )

Philyra concinnus Ghani & Tirmizi, 1995: 144–147 , fig 1a–h (material from Karachi).— Apel, 2001: 56; Ng et al. 2008: 92 (in list); Galil 2009: 281, tab 1; Naderloo & Türkay 2012: 32; Naderloo 2017: 109, figs 14.35c, 14.37, 14.38.

Philyra sexangula — Stephensen, 1946: 89.

Ebalia sagittifera — Cooper, 1997: 173, 174 (partly), fig 7.

Material examined. ZUTC 6925 , 1 male (CL 8.4 mm, CW 7.6 mm), 2 females (CL 9.3 mm, CW 8.2 mm; CL 9.4 mm, CW 8.4 mm), Hormoz Island, Persian Gulf , unknown collector and date ; ZUTC 1341 , 1 male, 1 female, coast of Bushehr, Persian Gulf , 28°58′N, 50°49′E, sandy/rocky, 10.2006, coll. R. Naderloo ; ZUTC 1342 , 2 males, 1 female, Qeshm I., Persian Gulf , coll. M. Asgari ; ZUTC 1343 , 1 male, 1 female, Badnar Kolahi, Strait of Hormoz , 27°02′N, 56°51′E, muddy-sand flat, 22.04.2008, coll. R. Naderloo ; ZUTC 1344 , 1 juvenile, East of city, Bandar-Abbas, Persian Gulf , 27°11′N, 56°21′E, muddy-sand flat with shells, 23.04.2008, coll. R. Naderloo, A. Kazemi, A. Keykhosravi ; ZUTC 1345 , 1 male, Jofreh, Bushehr, Persian Gulf , 28°58′N, 50°49′E, sandy/rocky, dead coral with algae, 24.05.2008, coll. R. Naderloo, A. Kazemi, H. Salehi.

Description. Carapace hexagonal ( Fig. 1E ), slightly longer than broad. Dorsal surface smooth except three narrow minutely granular ridges uniting to form "broad-arrow" pointing forwards, middle ridge extendingfrom progastric to intestinal region; lateral ridges extending backwards laterally to branchial region, running parallel to anterolateral margins, with ends projecting beyond posterolateral margins, forming larger denticles ( Fig. 1E ); regions relatively distinct, with elevated gastric, cardiac, branchial, intestinal regions; hepatic region excavated forming depression, upper and lower margins beaded, originating from middle of anterolateral margin, not merging anteriorly, broadly triangular tooth projecting on anterior half of lower margin of anterolateral border; anterolateral margin convex, shorter than posterolateral margin, merging with posterolateral margin to form broad triangular tooth; anterolateral, posterolateral, posterior margins beaded; epibranchial angle obtuse; posterolateral margin slightly sinuous; front smooth, almost straight, epistome visible beyond frontal margin from dorsal view; posterior margin almost straight, slightly convex, lateral sides with strong, pointed, outwardly directed spines, spines or small obtuse projections ( Fig. 1E ). Anterior margin of endostome reaching slightly beyond anterior margin of inhalent channels.

Maxilliped 3 ( Fig. 3C ) smooth, entirely covering endostome; merus with notch, two-thirds as long as ischium along inner margin; ischium two times longer than wide; carpus not visible in external view when reposed; propodus and dactylus visible in external view, articulating subdistally on inner surface of merus; exopod ( Fig. 3C ) outer margin convex, setose, much longer than wide, almost twice the length of merus.

Chelipeds ( Fig. 1E, F ) equal, as long as carapace length, granulated. Merus triquetral in cross-section with edges raised and granular; both inner and outer margins with tuberculated ridge. Carpus and propodus have raised row of granules along inner edge of their upper surface. Fingers slender, about two-thirds length of propodus, cutting edge of fingers toothed with scattered setae, median shallow canal extending to distal length of both fingers.

P2–P5 ( Fig. 1E ) subcylindrical; total length of all pairs almost similar, merus and carpus glabrous, merus longest as compared to carpus, propodus and dactylus. Carpus and propodus almost equal in length, dactylus large with tapering distal end.

Thoracic sternum ( Fig. 1F ) smooth, tuberculated on margins, slightly concave. Sternites 1–3 completely fused without any trace of sutures, sternite 3 separated from sternite 4 by shallow groove; sternite 4–6 almost similar in width, sternite 7 slightly tuberculated.

Male pleon ( Fig. 1F , 3D ) smooth with three articulating parts: somite 1 free, narrow; somite 2–6 fused, immovable, posterolateral angles with small bulge, somite 6 without any denticle; telson triangular, longer than broad with curved apex.

Female pleon ovate; somite 1 free; somites 2–6 fused, suture clearly visible between somites 2 and 3, partial suture visible between somites 3–4 and 5–6, forming domed plate almost completely covering thoracic sternum. Telson triangular, longer than broad, with curved apex ( Fig. 2D ).

G1 ( Fig. 4E, F ) shaft long, slender, straight, apical process long, about 0.2 times as long as whole length, more sinuous-shape, with spade-shape (spatulate) ending, apical lobe bearing setae almost length of the tip. Female gonopore ( Fig. 5D ) on inner anterior edge of sternite 5, oval in shape with broad opening.

Variation. The carapace of female resembles with that of male, except for lateral sides of posterior margin having sharp dorsoventrally flattened teeth ( Fig. 2C ).

Distribution. Pakistan ( Ghani & Tirmizi 1995), Persian Gulf [ Stephensen (1946) as Philyra sexangula ; Apel 2001; Naderloo & Türkay 2012; Naderloo 2017] and Gulf of Oman ( Naderloo et al. 2015).

Remarks. Ghani & Tirmizi (1995) described T. concinnus n. comb. on the basis of specimens collected from Karachi ( Pakistan) and Persian Gulf. As mentioned earlier, the Persian Gulf material examined by these authors is referable to T. sagittifera n. comb. ( Apel 2001; Naderloo & Türkay 2012; Naderloo 2017). Here we also confirm that the drawing of a Persian Gulf specimen by Ghani & Tirmizi (1995: fig. 2) agrees with type specimen of P. sagittifera in the following features: carapace hexagonal, smooth except three broad tuberculated ridges unite to form a "broad-arrow" point; epibranchial angle forming right angle, posterior margin convex, lateral sides with knob-like teeth having rounded tips, small median tooth present on the posterior margin in males; and G1 shaft straight, slender, with apical process slightly sinuous-shape, with tapering end.

The holotype and some of the paratypes of T. concinnus n. comb. deposited in the Marine Reference Collection and Resource Centre , University of Karachi , Karachi, Pakistan are not traceable despite many searches in the museum (Noor Saher, personal communication). The second author has examined the paratype specimens (1 male and 1 female) deposited in Naturalis Biodiversity Center, Leiden, but these are in very poor condition and of little use for identification. The fresh specimens from the Persian Gulf examined here are in agreement with the description and illustrations of holotype provided by Ghani & Tirmizi (1995).

Tirmilyra concinnus n. comb. closely resembles T. sagittifera n. comb. but can be differentiated from the latter species on the basis of several morphological characteristics that are discussed above in the remarks section of the latter species.

Figures

FIGURE 1. Tirmilyra sagittifera (Alcock, 1896) n. comb., lectotype male (CL 5.0 mm, CW 4.5 mm) (ZSI C910/10), Karachi, Pakistan: (A) dorsal view; (B) carapace dorsal view; (C) ventral view. Tirmilyra sagittifera (Alcock, 1896) n. comb., fresh specimen male (ZUMC CRU885) (CL 4.2 mm, CW 3.9 mm) Bushehr, Iran, Persian Gulf: (D) dorsal view. Tirmilyra concinnus (Ghani & Tirmizi, 1995) n. comb., fresh specimen male (CL 8.4 mm, CW 7.6 mm) (ZUTC 6925) Hormoz Island, Persian Gulf: (E) dorsal view; (F) ventral view.

FIGURE 2. Tirmilyra sagittifera (Alcock, 1896) n. comb., paralectotype female (CL 6.0 mm, CW 5.7 mm) (ZSI C910/10) Karachi, Pakistan: (A) dorsal view; (B) ventral view. Tirmilyra concinnus (Ghani & Tirmizi, 1995) n. comb., fresh female (CL 9.4 mm, CW 8.4 mm) (ZUTC 6925) Hormoz Island, Persian Gulf: (C) dorsal view; (D) ventral view.

FIGURE 3. Tirmilyra sagittifera (Alcock, 1896) n. comb., lectotype male (CL 5.0 mm, CW 4.5 mm) (ZSI C910/10), Karachi, Pakistan: (A) maxilliped 3; (B) pleon. Tirmilyra concinnus (Ghani & Tirmizi, 1995) n. comb., fresh specimen male (CL 8.4 mm, CW 7.6 mm) (ZUTC 6925) Hormoz Island, Persian Gulf: (C) maxilliped 3; (D) pleon.

FIGURE 4. Tirmilyra sagittifera (Alcock, 1896) n. comb., lectotype male male (CL 5.0 mm, CW 4.5 mm) (ZSI C910/10), Karachi, Pakistan: (A) G1 shaft; (B) G1 tip; Tirmilyra sagittifera (Alcock, 1896) n. comb., fresh specimen male (CL 4.2 mm, CW 3.9 mm) (ZMUC CRU885), Bushehr, Iran, Persian Gulf: (C) G1 shaft; (D) G1 tip; Tirmilyra concinnus (Ghani & Tirmizi, 1995) n. comb., fresh specimen male (CL 8.4 mm, CW 7.6 mm) (ZUTC 6925) Hormoz Island, Persian Gulf: (E) G1 shaft; (F) G1 tip.

FIGURE 5. Tirmilyra sagittifera (Alcock, 1896) n. comb., paralectotype female (CL 6.0 mm, CW 5.7 mm) (ZSI C910/10) Karachi, Pakistan: (A) frontal view of cephalothorax; (B) female gonopore (right side); Tirmilyra concinnus (Ghani & Tirmizi, 1995) n. comb., fresh female (CL 9.4 mm, CW 8.4 mm) (ZUTC 6925) Hormoz Island, Persian Gulf: (C) frontal view of cephalothorax; (D) female gonopore (right side).