Bellayra, Mitra, 2022

Mitra, Jigneshkumar Trivedi Reza Naderloo Chinnathambi Viswanathan Santanu, 2022, Redescription of Philyra sexangula Alcock, 1896 (Decapoda, Brachyura, Leucosiidae), with description of a new genus and species from the northern Indian Ocean, Nauplius (e 2022026) 30, pp. 1-12 : 2-4

Bellayra gen. nov.

Zoobank: urn:lsid:zoobank.org:act:DFEA5A1E-511C-4DCE-9A1A-119367DED2DB

Type species. Philyra sexangula Alcock, 1896 , by present designation (gender feminine)

Other species included. Bellayra taekoae ( Takeda, 1972) gen. nov., comb. nov. (type locality: Japan), Bellayra nishihirai ( Takeda and Nakasone, 1991) gen. nov., comb. nov. (type locality: Japan), Bellayra persicum gen. nov., sp. nov. (type locality:Persian Gulf).

Diagnosis. Carapace rhomboidal, markedly punctuate, punctae extending to ventral surface; regions well defined with granules. Anterolateral and posterolateral margins of carapace with obtuse tubercle. Male pleon ( Figs. 1d , 2d ) with 3 articulating somites, somite 1 narrow, median part slightly protruding, somites 2– 6tightly fused, distinct median denticle on somite 6, telson with rounded apex; female pleon with 4 articulating somites, somites 3 –6 tightly fused. G1 straight or twisted with broad triangular or twisted apical lobe.

Description. Carapace rhomboidal, slightly broader than long, dorsal surface convex with small to moderately large granules, with numerous punctae extending to ventral surface, regions relatively distinct; gastric, cardiac, branchial, intestinal regions elevated with scattered granules. Front weakly concave, with small median protuberance, epistome and anterior boundaries of pterygostomial regions projecting beyond edge of front, visible dorsally. Median tuberculated ridge undulating, running from frontal region merging with elevated intestinal region; hepatic facet broad, shallow, upper and lower margins beaded, not merging anteriorly, joining with anterolateral margin posteriorly;single row of tubercles on branchial region may be present; anterolateral, posterolateral, and posterior margins rimmed by obtuse tubercles. Posterior margin with angulated lateral ends on both sides. Third maxillipeds granular, merus almost as long as ischium, ischium longer than wide, exopod elongated, expanded, row of long setae on merus and ischium. Cheliped not inflated or elongate, merus granular, cutting edges of fingers with narrow gap when closed. Ambulatory legs slender, smooth. Male pleon ( Figs. 1d , 2d ) with 3 articulating somites, covered with numerous punctae; somite 1 narrow, median part slightly protruding; somites 2 – 6 fused, immovable, with distinct median denticle on somite 6, telson long with rounded apex.Female pleon with 4 articulating somites; first and second somites narrow, covered with small granules, third to sixth somites fused, smooth, lateral margins granular; telson long, ellipsoidal. G1 long, slender, straight or twisted along most of length, tip triangular or twisted.

Etymology: The genus is named in honor of Bella Galil for her valuable contribution to the taxonomy of the family Leucosiidae . The name is in arbitrary combination with the suffix of the genus name Philyra .

Remarks: Galil (2009), in her revision of Philyra

Leach, 1817, separated it into two groups of genera.The first group has the first two male pleonal somites free ( Philyra sensu stricto, Afrophila Galil, 2009 , Atlantolocia Galil, 2009 , Ryphila Galil, 2009 , and Ovilyra Ng, 2021 ) while the second group has the first male pleonal somite articulated ( Atlantophila Galil, 2009 , Lyphira Galil, 2009 , Pyrhila Galil, 2009 , Hiplyra Galil, 2009 ). In this regard, Bellayra gen. nov. belongs to the second group. However, Bellayra gen. nov. can be immediately distinguished from the other genera of the second group on the basis of the following characters: rhomboidal carapace, carapace covered with moderate to large granules with numerous punctae which extend to ventral surface, and male G1 straight or twisted with broadly triangular or twisted apical lobe. The morphological comparison between Bellayra gen. nov. and closely related genera is given in Tab. 1.

Kemp (1915), while describing Philyra alcocki Kemp, 1915 , wrote that the first two male pleonal somites are immobile but the first author has examined the type and fresh specimens of P.alcocki and observed that the first two somites of the male abdomen are free. This indicates that P.alcocki belongs to the first group of genera identified by Galil (2009). Kemp (1915) also commented that P.alcocki shows some resemblance to B. sexangula ( Kemp, 1915) , but these two species are very different in terms of carapace shape (rhomboidal vs. suborbicular in P. alcocki ), frontal margin (no median tooth vs. median tooth in P. alcocki ), male pleonal somite 1 and 2 (1 st somite free vs. 1 st and 2 nd are free in P. alcocki ), G1 apical lobe (triangular vs. spatuliform in P. alcocki ) and they are certainly not congeneric ( Trivedi et al., 2022). Philyra alcocki is now referred to the new genus Alcolyra Trivedi, Mitra and Ng, 2022 ( Trivedi et al., 2022).

Japanese species, Philyra taekoae Takeda,1972 and Philyra nishihirai Takeda and Nakasone, 1991 , show affinities towards Bellayra n. gen. in the following characters: rhomboidal carapace, carapace covered with moderate to large granules with numerous punctae which extend to the ventral surface, male pleon with first pleonal somite free, and male G1 straight with triangular or twisted apical lobe respectively ( Takeda, 1972; Sakai, 1976; Takeda and Nakasone, 1991; Rahayu and Ng, 2003). Philyra nishihirai and P. taekoae are herewith referred to Bellayra gen. nov.

Figures

Figure 1. Bellayra sexangula gen. nov., comb. nov., lectotype, male (CL 7.24 mm, CB 7.85 mm) (ZSI-893/10). a, Habitus, dorsal view; b, right cheliped, outer view; c, right cheliped, inner view; d, carapace, ventral view.

Figure 2. Bellayra sexangula gen. nov., comb. nov., male (CL 7.3 mm, CB 8.15 mm) (LFSc. ZRC-149). a, Habitus, dorsal view; b, right cheliped, outer view; c, right cheliped, inner view; d, carapace, ventral view; e, carapace, lateral view.