Bellayra sexangula ( Alcock, 1896 ), 2022

Bellayra sexangula ( Alcock, 1896) View in CoL gen. nov., comb. nov.

( Figs. 1–3 View Figure 1 View Figure 2 View Figure 3 )

Philyra sexangula Alcock, 1896: 238 View in CoL , 241, 242, pl. VII, fig. 2.— Ng et al., 2008: 93 (in list).— Galil, 2009: 281 (in list).— Dev Roy, 2017: 209, 225 (in list).— Trivedi et al., 2018: 49 (in list).

Material examined. Lectotype (here designated), male (CL 7.24 mm, CB 7.85 mm) (ZSI-893/10), Sacramento shoal, Godavari coast, Andhra Pradesh State, India . Other material: male (CL 7.30 mm, CB 8.15 mm), (LFSc.ZRC-149), Pichavaram mangrove forest, Tamil Nadu, India, 11°26’20”N 79°47’54”E, 4.II.2018, coll. Mariasingarayan Yosuva. GoogleMaps

Comparative material: Bellayra nishihirai gen. nov., comb. nov.: 2 females (CL 4.4 mm, CB 5.3 mm, CL 4.9 mm, CB 5.7 mm) ( ZRC 2002.601 View Materials ); 1 male (CL 5.9 mm, CB 6.3 mm) ( ZRC 2002.602 View Materials ), sandy-mud substrate in mangrove near river mouth, Kamora , Irian Jaya, Indonesia, 22.IX.2001, coll. I. Ermayanti ; 1 female (CL 4.6 mm, CB 5.5 mm) ( ZRC 2002.608 View Materials ), sandy-mud substrate in mangrove near river mouth, Kamora , Irian Jaya, Indonesia, 10.VII.2001, coll. A. Pratiwi.

Diagnosis. Carapace rhomboidal, slightly broader than long; dorsal surface punctuated, minutely granular; regions relatively defined, elevated, tuberculated ridge along median part,tubercles getting larger in cardiac and intestinal regions; lateral margins finely tuberculate, epibranchial angle obtuse, distinct tubercle on posterolateral margin; posterolateral angle with prominent obtuse tubercle. Chelipeds robust, large, about 2.5 times as long as carapace width. Male pleon with 3 articulating somites, somites 2 to 6 tightly fused; somite 6 with distinct median denticle; telson broadly triangular, longer than broad. G1 straight along most of length, tapering at tip,apical lobe ( Fig. 3f, h View Figure 3 ) with long setae.

Redescription. Carapace rhomboidal ( Figs. 1a View Figure 1 , 2a View Figure 2 ), slightly broader than long. Dorsal surface strongly convex; minutely granular with numerous punctae which extend to the ventral surface( Figs.1d View Figure 1 , 2d View Figure 2 ),regions relatively distinct; cardiac, branchial, intestinal regions elevated, metagastric, urogastric, cardiac regions elevated with small truncate tubercle medially,elevated intestinal region with large truncate tubercle medially conf luent with elevated cardiac region ( Fig. 2e View Figure 2 ), undulating median tuberculated ridge running from frontal region, merging with elevated intestinal region, reaching highest elevation in metagastric region ( Fig. 2e View Figure 2 ); mesogastric region indicated anteriorly with median row of small granules, concave laterally; protogastric region depressed; branchial region with tuberculated ridge running slightly on the median part of posterolateral margin, anterior part longitudinal, posterior part oblique; hepatic facet broad, shallow, floor of facet with numerous punctae, upper and lower margins beaded, not merging anteriorly, posteriorly, facet joining anterolateral margin at well marked obtuse angle. Anterolateral, posterolateral, posterior margins rimmed by obtuse tubercles; epibranchial angle obtuse; posterolateral margin sinuous, slightly concave. Front slightly elevated, weakly concave, with small median proturbance. Posterior margin almost straight, weakly beaded.

Third maxillipeds( Fig.3c View Figure 3 ) covered with numerous punctae; merus 0.9 times as long as ischium along inner margin; ischium 1.6 times longer than wide; basis expanded, more than half length of exopod; carpus, propodus and dactylus not visible in external view when reposed, articulating on inner surface of merus, dactylus apex with long setae.Exopod ( Fig.3c View Figure 3 ) much longer than wide, about twice length of merus, outer and inner margins with fringes of setae.

Chelipeds ( Figs. 1a, b, c View Figure 1 , 2a, b, c View Figure 2 ) about 2.5 times length of carapace width.Merus with upper and lower margins beaded, outer surface with tuberculated ridge running parallel to upper margin, inner surface smooth. Carpus about one-third length of merus, elevated medially. Palm ( Figs. 1a, b, c View Figure 1 , 2a, b, c View Figure 2 , 3a, b View Figure 3 ) longer than dactylus, upper and lower margins beaded, outer surface smooth ( Figs. 1b View Figure 1 , 2b View Figure 2 , 3a View Figure 3 ), inner surface ( Figs. 1c View Figure 1 , 2c View Figure 2 , 3b View Figure 3 ) with 3 ridges, lower most ridge tuberculated running parallel to lower margin of palm. Dactylus outer margin smooth, inner margin with ridge running parallel to upper margin. Pollex outer margin smooth, inner margin with ridge running parallel to lower margin. Cutting edges of fingers with blunt denticles covered with scattered setae ( Figs. 1b, c View Figure 1 , 2b, c View Figure 2 , 3a, b View Figure 3 ).

P2–P5 ( Figs. 1a View Figure 1 , 2a View Figure 2 ) subcylindrical; total length decreasing from first to last pair, glabrous, upper and lower margins of propodus and dactylus covered with long setae.

Thoracic sternum covered with numerous punctae, with thickened margins along the bases of ambulatory legs. Sternopleonal cavity deep, reaching to mid-distance between fused thoracic sternites 1–3 ( Figs. 1e View Figure 1 , 2e View Figure 2 , 4a View Figure 4 ); margin lined with granules, those on distal part proportionately larger ( Figs. 1d View Figure 1 , 2d View Figure 2 ).

Male pleon ( Figs. 1d View Figure 1 , 2d View Figure 2 , 3d View Figure 3 ) with 3 articulating somites, covered with numerous punctae, somite 1 narrow, with posterolateral angle tuberculated, median part slightly protruding with few tubercles; somite 2 to 6 fused, immovable, complete suture between somites 2 and 3 as well as 5 and 6 visible, distinct denticle on middle portion of somite 6, telson longer than broad, broadly triangular, with rounded apex. G1 ( Fig. 3e, g View Figure 3 ) long, slender, straight along most of length, tapering at tip, apical lobe ( Fig. 3f, h View Figure 3 ) with long setae.

Distribution. So far known only from India: Andhra Pradesh ( Alcock, 1896; Dev Roy, 2017); Tamil Nadu (present study).

Remarks. Alcock (1896) described P. sexangula on the basis of two male specimens: one male collected from Sacramento Shoal, Godavari coast, Andhra Pradesh State, India, and the other one from the Persian Gulf. No holotype was selected so both specimens are syntypes. We examined both syntypes in the ZSI and they are actually not conspecific. The male specimen from India agrees best with the figure and description provided by Alcock (1896: 240, pl. VII,fig. 2) and we believe the figure was actually based on it. As such,we here select the Indian male (CL 7.24 mm, CB 7.85 mm) (ZSI-893/10) as the lectotype of P.sexangula Alcock, 1896 . This lectotype agrees very well with our recent male specimen from Tamil Nadu in India LFSc.ZRC-149).The other syntype male, (CL 7.88 mm, CB 7.83 mm, ZSI-896/10) from the Persian Gulf is here made the holotype for a new species, B. persicum gen. nov., sp. nov.

Bellayra sexangula gen. nov., comb. nov. most closely resembles B. persicum gen. nov., sp. nov. but differs in the following characters: carapace highly granular with abundant punctae ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. carapace relatively less granular with scattered punctae in B. persicum gen. nov., n. sp., Fig. 4a View Figure 4 ); median ridge having five denticles ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. single broad denticle present on mesogastric region in B. persicum gen. nov., n. sp., Fig. 4a View Figure 4 ); median denticle present on sixth abdominal somite small and narrow ( Figs. 1d View Figure 1 , 2d View Figure 2 ) (vs. large and broad in B. persicum gen. nov., n. sp., Fig. 4d View Figure 4 , 5d View Figure 5 ); G1 main shaft straight ( Figs. 2h, 2e View Figure 2 ) (vs. G1 main shaft twisted two times in B. persicum gen. nov., n. sp., Fig. 5e View Figure 5 ); and tip of the G1 is broadly triangular ( Figs. 2e, 2f View Figure 2 ) (vs. tip of G1 tubular in B. persicum gen. nov., n. sp., Fig. 5f View Figure 5 ).

Bellayra sexangula View in CoL gen. nov., comb. nov. can be distinguished from B. nishihirai View in CoL gen. nov., comb. nov. (type locality: Oura River, Okinawa-Jima Island, Japan) in the following characters: mesogastric region of carapace smooth laterally ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. a row of granules in B. nishihirai View in CoL , Fig. 6a View Figure 6 ; Takeda and Nakasone, 1991:fig. 2A; Rahayu and Ng,2003: fig. 2); hepatic region without row of tubercles ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. with single row present in B. nishihirai View in CoL , Fig. 6a View Figure 6 ; Rahayu and Ng,2003:fig.2); posterior margin straight ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. weakly concave B. nishihirai View in CoL , Fig.6a View Figure 6 ; Takeda and Nakasone, 1991: fig. 2A; Rahayu and Ng, 2003: figs. 1a, 2); cheliped merus outer surface with tuberculated ridge running parallel to upper margin ( Figs. 1a–c View Figure 1 ; 2a–c View Figure 2 ) (vs. rows of scattered granules in B. nishihirai View in CoL , Fig. 6a View Figure 6 ; Takeda and Nakasone, 1991: fig. 2D; Rahayu and Ng, 2003: figs. 2, 3a); palm inner surface with three ridges ( Figs. 1c View Figure 1 , 2c View Figure 2 , 3b View Figure 3 ) (vs. with only scattered granules present in B. nishihirai View in CoL , Fig. 6a View Figure 6 ; Takeda and Nakasone, 1991: fig. 2D; Rahayu and Ng, 2003: fig. 3a); the third maxilliped merus apex is rounded ( Fig. 3c View Figure 3 ) (vs. angular in B. nishihirai, Takeda and Nakasone, 1991 View in CoL : fig. 2C; Rahayu and Ng, 2003: fig. 3i); the inner and outer margin of merus are smooth ( Fig.3c View Figure 3 ) (vs. beaded in B. nishihirai View in CoL , see Takeda and Nakasone, 1991: fig. 2C; Rahayu and Ng, 2003: fig. 3i); the pleonal abdominal somites 2 – 6 are fused with two complete sutures ( Figs. 1d View Figure 1 , 2d View Figure 2 , 3d View Figure 3 ) (vs. no complete sutures but with only three lateral incisions in B. nishihirai View in CoL , Fig. 6b View Figure 6 ; Takeda and Nakasone, 1991: fig. 2E); lateral margins of pleonal somites 1 and 2 smooth ( Figs. 1d View Figure 1 , 2d View Figure 2 , 3d View Figure 3 ) (vs. beaded in B. nishihirai View in CoL , see Takeda and Nakasone, 1991: fig. 2E); telson broadly triangular and 1.1 times as long as broad ( Figs. 1d View Figure 1 , 2d View Figure 2 , 3d View Figure 3 ) (vs. narrow and 1.8 times as long as broad in B. nishihirai View in CoL , see Takeda and Nakasone, 1991: fig. 2E; Rahayu and Ng, 2003: fig. 3c); and the G1 apical lobe broadly triangular ( Fig. 3f, h View Figure 3 ) (vs. twisted in B. nishihirai View in CoL , see Takeda and Nakasone, 1991: figs. 2F, 2G; Rahayu and Ng, 2003: figs. 3d,3e).

Bellayra sexangula View in CoL gen. nov., comb. nov. can be distinguishedfrom B.taekoae View in CoL gen.nov.,comb.nov. (type locality: Sumiyo, Amami-Oshima Island of Ryukyu Island, Japan) in the following characters:carapace less tuberculated ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. strongly tuberculated in B. taekoae, Takeda, 1972 View in CoL : Fig. 1A View Figure 1 ; Takeda and Nakasone, 1991: fig. 1D); carapace median area without large tubercles ( Figs. 1a View Figure 1 , 2a View Figure 2 )(vs. median row of large tubercles in B. taekoae View in CoL , see Takeda, 1972: fig.1A; Takeda and Nakasone, 1991: fig.1D); intestinal region with single large truncate tubercle ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. intestinal region covered with numerous tubercles in B. taekoae View in CoL , see Takeda, 1972: fig. 1A; Takeda and Nakasone, 1991: fig. 1D); single row of tubercles present on branchial region ( Figs. 1a View Figure 1 , 2a View Figure 2 ) (vs. no row of tubercles present in B. taekoae View in CoL , see Takeda, 1972: fig. 1A; Takeda and Nakasone, 1991: fig. 1D); third maxilliped merus apex is rounded ( Fig. 3c View Figure 3 ) (vs. angular in B. taekoae View in CoL , see Takeda, 1972: fig. 1B; Takeda and Nakasone, 1991: fig.1F);third maxilliped exopod outer border strongly convex ( Fig. 3d View Figure 3 ) (vs. gently convex in B. taekoae View in CoL ,see Takeda, 1972: fig. 1B; Takeda and Nakasone, 1991: fig. 1F); male pleon with sutures between somites 2 and 3 as well as 5 and 6 visible ( Fig. 3d View Figure 3 ) (vs. sutures absent in B. taekoae View in CoL , see Takeda and Nakasone, 1991: fig. 1E); and male G1 apical lobe tip pointed (vs. tip rounded in B. taekoae View in CoL , see Sakai, 1976: text fig. 63b, c).