Banareia metiguinotae, Prema & Ravichandran & Mendoza, 2023

Prema, Mani, Ravichandran, Samuthirapandian & Mendoza, Jose Christopher E., 2023, A new species of the xanthid crab genus Banareia A. Milne-Edwards, 1869 (Crustacea: Brachyura: Xanthidae) from the Bay of Bengal, southeastern India, Raffles Bulletin of Zoology 71, pp. 387-399 : 389-396

publication ID	https://doi.org/ 10.26107/RBZ-2023-0029
publication LSID	lsid:zoobank.org:pub:0A47221A-B652-4929-B4CA-0DD4535B7880
persistent identifier	https://treatment.plazi.org/id/E361E4E4-1FC5-41A3-8975-D3CBE7F28138
taxon LSID	lsid:zoobank.org:act:E361E4E4-1FC5-41A3-8975-D3CBE7F28138
treatment provided by	Felipe
scientific name	Banareia metiguinotae
status	sp. nov.

Treatment

Banareia metiguinotae View in CoL , new species

( Figs. 1A View Fig , 2A–C View Fig , 3A–C View Fig , 4A–C, E View Fig , 5 View Fig , 6 View Fig )

Material examined. Holotype: female (40.5 × 27.8 mm) ( CASAU CR 2020-1020 ), bycatch of commercial trawlers, depth 100–200 m, 11°32.134′N 79°57.66′E, Pazhayar fishing port, Tamil Nadu, coll. M. Prema & S. Ravichandran, 8 January 2020. GoogleMaps

Paratype: 1 female (41.9 × 29.2 mm) ( CASAU CR 2023- 1026 ), coll. 26 February 2023, other data same as holotype GoogleMaps .

Other material: 1 male (37.0 × 25.1 mm), ( CASAU CR 2018-1041 ) , 1 female (47.0 × 35.0 mm) ( CASAU CR 2018-1042 ), coll. 7 April 2018, other data same as holotype [Note: These specimens were examined, photographed, and illustrated by MP & SRC but were subsequently misplaced while in transit by courier and could not be found] GoogleMaps .

Comparative material examined. Banareia serenei Guinot, 1976 : holotype, male (52.0 × 35.0 mm) (MNHN- IU-2014-22606 (= MNHN-B7224 ), from commercial nearshore trawler, depth 20–30 m, Nha Trang Bay , Vietnam, coll. Nguyen Van Luom, 1970.

Diagnosis. Carapace transversely subovate, broader than long (CW/CL ratio 1.34–1.47); anterolateral margins arcuate, divided into four broad lobes, anterior two granulose, posterior two further armed with large conical teeth; first lobe wide, flat, separated from external orbital angle by shallow concavity; second lobe similar to first but narrower; third lobe with one large conical tooth each on anterior and posterior ends, margin in between granulose, concave; fourth (last) lobe extends inward into branchial region as a granular ridge, armed with several granular or conical teeth, anteriormost of which being the largest and marking widest point of carapace, other teeth decreasing in size posteriorly until reduced to granules. Dorsal surface of carapace moderately setose, with numerous round granules, shallow furrows with dense tomentum. Chelipeds subequal, robust, external surface of palm setose, granular, with longitudinal rows of granules around midline and near ventral margin. Ambulatory legs moderately long, stout, densely covered with long and short setae, posterior margin of meri lined with large granules. G1 long, slender, curving laterally from base to tip, distal tip laterally concave, slightly narrower than main shaft, with numerous simple setae covering most distal part, subdistal sternal margin with short, spiniform setae, sternal surface smooth, dorsolateral margin with seven short, hooked spines. G2 short, less than half length of G1, sigmoid in shape with tapering distal end, terminal segment about one-third length of subdistal segment, lateral margin of subdistal segment lined with short setae.

Description. Female holotype: Carapace ( Figs. 1A View Fig , 2A View Fig , 5A View Fig ) transversely subovate, 1.4 times as broad as long, dorsal surface granular, moderately setose, strongly convex longitudinally and transversely, regions well defined, separated by narrow, smooth, tomentose furrows; 1F flat, distinct from areolate 2F; 2F separated from 1M by shallow transverse furrow; 2M tripartite, elongate, innermost branch completely separate from middle and outermost branches and fused with 1M, middle and outermost branches nearly separate, fused at base forming a “V”; 3M tripartite, areoles separated by narrow furrows, middle anterior areole long and narrow, 2 basal areoles subovate, wide; 4M, 2L, 3L, 6L distinct, entire; 1L indistinct, depression formed by islets of granules; 4L merging with third lobe of carapace anterolateral margin; 5L partially divided by thin, longitudinal furrow; 1P long, completely divided by shallow median longitudinal furrow; 2P with scattered clumps or indistinct rows of granules; 1R merged with posterolateral teeth, 2R separated from 3R by distinct, subdivided, several small prominent granular islets, surface not very uniform in appearance. Similarly, supra-, infraorbital margins, subhepatic, pterygostomial regions finely granular and setose; subhepatic region with narrow grooves originating from clefts between lobes of carapace anterolateral margin, particularly around third lobe. Front projecting beyond the level of orbits, bilobate, lobes separated by deep fissure which continues as a furrow and connects with anterior tip of 3M, frontal margins strongly concave, granular. Orbits relatively small, width about 0.2 times carapace width; supraorbital margin with three incisions, granular, separated from front by distinct incision; infraorbital margin continuous, granular, infraorbital tooth pointed, not visible in dorsal view, abutting basal antennal article. Anterolateral margin arcuate, granular, gradually connected by line of low granules to supraorbital margin, separated from external junction of supra- and infraorbital margins (exorbital angle) by small, smooth concavity; anterolateral margin divided into four broad granular lobes; first, anterior most lobe wide, truncate, margin nearly straight, separated from second lobe by shallow but distinct notch; second lobe similar to first but narrower, margin distinctly convex; third lobe widest, with one large conical tooth each on anterior and posterior ends, margin in between these teeth granulose, concave; fourth, posterior most lobe more acutely triangular, apex surmounted by large conical tooth which marks widest point of carapace, posterior margin extending inward onto branchial region as a granular ridge, armed with several granular teeth decreasing in size posteriorly until reduced to granules. Posterolateral margins concave, lined with numerous small granules, concavity for receiving posterior ambulatory legs when folded against carapace (coaptation); posterior margin slightly sinuous, lined with minute, round granules.

Eyes ( Fig. 2B, C View Fig ) with short, stout peduncles, filling entire orbit, distal part of ocular peduncle finely granular, covered by short dense tomentum; corneas well developed. Basal antennal article ( Fig. 2B, C View Fig ) broadly sub-rectangular, granular, occupying, but not completely filling orbital hiatus, immobile, flagellum entering orbital hiatus, tip reaching external orbital margin when extended. Antennular fossa ( Fig. 2B, C View Fig ) sub-rectangular, antennules folding transversely, slightly diagonally, antennular fossa sealed completely by basal antennular segment, outer region deeply grooved. Epistome well developed ( Fig. 2B, C View Fig ), posterior region well divided into 1 central and 2 lateral lobes by 2 wide clefts; central lobe without pronounced median tooth or protuberance, margin nearly straight; margins of lateral lobes nearly straight, laterally two lines of evenly arranged rounded granules stretching towards pterygostomian region. Endostomial ridges indiscernible.

Buccal aperture not completely closed by third maxillipeds ( Fig. 2C View Fig ), which form large gap between them. Third maxilliped elongated, external surfaces smooth with scattered granules mesially; merus subquadrate, with short setae on external surface, anteroexternal angle not extended, longitudinal submedian groove with oblique sulcus, mesial margin minutely granulated; ischium longer than broad, with shallow submedian sulcus, submedian granular ridge, distal part of lateral margin nearly straight, mesial margin cristate, minutely dentate; separated from basis by thin furrow. Exopod slender, smooth, tapering distally, tip just reaching anterior edge of merus, flagellum long, exceeding width of merus when extended.

Thoracic sternum ( Fig. 4A View Fig ) narrow; sternites 1, 2 fused, forming large, minutely granular, triangular plate which impinges in between and separates third maxilliped ischia, posterior margin of sternite 2 lined with large round granules ( Fig. 2C View Fig ); suture between sternites 2, 3 distinct, complete, marked by deep furrow; sternite 3 short, exposed surface granular, setose; suture between sternites 3, 4 incomplete, marked by cleft on lateral edges and wide, V-shaped furrow medially; sternite 4 large, granular, median line present on smooth area anterior to telson, extending into sternopleonal cavity; sternites 5, 6, 7 with intervening sutures interrupted at midline, suture between sternites 7, 8 complete; median line absent at level of sternites 5, 6, present at level of sternites 7, 8. Sternopleonal cavity granular, shallow; sterno-pleonal locking tubercle on sternite 5 effaced. Vulvae positioned mesially on sternite 6, near suture with sternite 5, large, opening C-shaped, facing mesially.

Chelipeds (P1) ( Figs. 1A View Fig , 3A, B View Fig , 5A View Fig ) subequal, robust; external surface abundantly covered with granules, short stiff setae. Merus short, only distalmost tip visible from dorsal view, indistinctly granular. Carpus short, broad, external surface rugose, with clumps of coarse granules, internal surface smooth, dorsal and ventral margins lined with densely arranged round granules, internal angle rounded, unarmed. External surface of palm granular, upper third of palm with scattered granules, middle part with two parallel rows of larger granules, lower part with irregularly, densely arranged granules and 1 row of round granules extending to proximal third of fixed finger; superior margin of palm subcristate, slightly convex, raised above line of superior margin of adjacent dactylus; inferior margin of palm sinuous, convex subproximally, concave at junction with fixed finger. Fingers shorter than midlength of palm, flattened, external surfaces pitted; proximal half of cutting margins with irregular subtriangular teeth, distal half blade-like, especially in fixed finger; superior margin of dactylus lined with round granules on proximal two-thirds.

Ambulatory legs (P2–P5) ( Figs. 1A View Fig , 3C View Fig , 5 View Fig ) short (P3 longest, combined merus–dactylus length less than maximum carapace width, P3 length/CW ratio 0.75); robust, dorsal surfaces covered with short setae, margins lined with long setae. Meri sub-rectangular; P5 merus length/width ratio 2.6, dorsal surface smooth, upper margin slightly convex, minutely granular, lower margin slightly concave, with larger round granules especially proximally. Carpi elongatedly trapezoidal, distinctly shorter than corresponding merus, narrowest proximally, widest distally, dorsal surface smooth, with submarginal sulcus near upper margin, upper and lower margins smooth. Propodi sub-rectangular, distinctly shorter than corresponding carpus, smooth, upper and lower margins slightly convex, smooth. Dactyli slender, distinctly longer than corresponding propodus, nearly straight except for slightly curved distal tip, tapering distally and ending in simple chitinised claw.

Pleon ( Figs. 4B View Fig , 6B View Fig ) subovate in outline, lateral margins distinctly convex, covering most of thoracic sternum except sternite 1, 2 and anterior portion of sternite 3; somites freely articulated, somite 4 broadest, somite 6 longest, telson subtriangular, short tomentum on the surface, punctate, and margins covered by dense short and long setae.

Male: Somatic (non-sexual) characters similar to female holotype. Thoracic sternum ( Fig. 4C View Fig ) densely packed with prominent granules, these granules stronger than dorsal surface of carapace, punctate; sternites 1, 2 completely fused, triangular, bordered by large pearliform granules; suture between sternites 2, 3 distinct, in deep groove. Sternites 3, 4 almost completely fused, suture 3/4 medially interrupted, represented by long transverse furrow medially and short lateral clefts on either side. Sternite 4 broad, median line present, just anterior to telson. Exposed portions of sternites 5, 6 relatively broad, much broader than respective episternites; exposed portion of sternite 7 narrower, only slightly broader than its episternite; sternite 8 not exposed when pleon is closed. Sutures 4/5, 5/6, 6/7 distinct in sternal plate and medially interrupted in sternopleonal cavity; suture between sternites 7, 8 complete; median line absent at level of sternites 5, 6, present at level of sternites 7, 8. Tubercle of sternopleonal lock well developed, on anterior portion of sternite 5, close to suture with sternite 4.

Pleon ( Figs. 4C, E View Fig & 6A View Fig ) relatively broad, short, tip of telson just reaching imaginary transverse line between sternal condyles of P1 coxae; short tomentum on surface. Telson subtriangular, smooth, apex round, lateral margins straight, basal margin convex, basal width slightly greater than median length, tightly fitted into sterno-pleonal cavity; somite 6 subquadrate, slightly wider than long, smooth, anterior and lateral margins concave, posterior margin sinuous; somites 3–5 fused, traces of sutures seen as lateral notches and mesial grooves, lateral margins sinuous and largely concave, somite 3 widest, somites 4, 5 smooth, somite 3 with minute granules scattered on surface; somite 2 subtrapezoidal, granular, lateral margins rounded, anterior margin sinuous, central region of posterior margin distinctly convex; somite 1 subtrapezoidal, somewhat curved, granular, broader than somite 2, anterior margin concave, posterior margin slightly convex, lateral margins straight.

G1 ( Fig. 6C, D View Fig ) curving laterally from base to tip; slender, distal tip laterally concave, slightly narrow, numerous long,

simple setae covering most distal part; subdistal sternal margin with short, sharp setae, sternal surface smooth, dorsolateral margin with seven short, hooked spines.

G2 ( Fig. 6E View Fig ) short, less than half length of G1, sigmoid in shape with tapering distal end; terminal segment about one-third length of subdistal segment, lateral margin of subdistal segment lined with short setae.

Etymology. This species is dedicated to and named in honour of Prof. Danièle Guinot (MNHN), for her tremendous contribution to the taxonomy and systematics of brachyuran crabs, particularly the Xanthidae , which has been most helpful in the present study, and for her generous mentorship of her carcinological colleagues both young and old. The specific epithet is an arbitrary combination of metis (Gr. counsel, wisdom) and Guinot, and is used as a noun in apposition.

Colour in life. The holotype is almost entirely light brown in colour due to its tomentum; the underlying calcareous exoskeleton, however, is off-white except the fingers of the chelae, which are brownish black throughout most of their length, turning white only at the tips, and the claws of the ambulatory dactyli, which are dark brown ( Fig. 5A, B View Fig ).

Ecological note. The crabs were collected by commercial trawlers from depths of 100–200 m, where the seafloor substrate consists of fine mud.

Distribution. Banareia metiguinotae , new species, is currently known only from the type locality, off the southeastern coast of Tamil Nadu, India, in the southwestern region of the Bay of Bengal.

Genetic data. The partial sequence of the COI gene, derived from the female holotype ( CASAU CR 2020-1020 ), contains 709 bp, and the sequence data is deposited in the NCBI GenBank, with the accession code OM791611 .

Remarks. Banareia metiguinotae , new species, fits well within the genus as defined by Guinot (1976) and Serène (1984), particularly in the following characters: the wide, subovate carapace, which is quite convex dorsally, with the anterolateral margins divided into lobes, instead of teeth, by thin clefts; the presence of narrow grooves on the subhepatic region of the carapace; the blade-like fingers of the chela which cross at the tips; the relatively wide clefts on the epistome; and the subquadrate merus of the third maxillipeds. Among the 16 species of Banareia currently recognised ( Ng et al., 2008), B. metiguinotae , new species, is morphologically most similar to B. serenei Guinot, 1976 (type locality: Nha Trang Bay, Vietnam), particularly in the general outline of the carapace and the division of the anterolateral margin whereby the third lobe is exceptionally long and has a concave margin, and the fourth lobe is sharply dentiform ( Figs. 1 View Fig , 2A, D View Fig ). Several reliable morphological features, however, distinguish the two species: (1) the carapace is relatively narrower and its dorsal surface relatively more convex in B. metiguinotae ( Figs. 1A View Fig , 2A View Fig ) (vs. carapace relatively broader and more flattened in B. serenei ; Figs. 1B View Fig , 2D View Fig ); (2) the median cleft of the front is relatively shallower, and the mesial angles of the frontal lobes are rounded in B. metiguinotae ( Figs. 1A View Fig , 2A, B View Fig ) (vs. the median cleft of the front is wider and deeper, the mesial angles of the frontal lobes are sharper in B. serenei ; Figs. 1B View Fig , 2D, E View Fig ); (3) the third lobe of the carapace anterolateral margin has distinct conical teeth on its anterior and posterior angles and the fourth lobe is surmounted by a large conical tooth ( Figs. 1A View Fig , 2A View Fig ) (vs. third lobe without well-formed teeth and the fourth lobe is surmounted by a wider, prismatic, granular tooth in B. serenei ; Figs. 1B View Fig , 2D View Fig ); (4) the margins on the inner surfaces of the chelar palm and dactylus have smaller, somewhat scattered granules in B. metiguinotae ( Fig. 3B View Fig ) (vs. larger conical granules lined uniformly in B. serenei ; Fig. 3E View Fig ); (5) the ambulatory legs are relatively longer (P5 length/CL = 0.73), and the anterior margin of the P5 merus is nearly straight in B. metiguinotae ( Fig. 3C View Fig ) (vs. ambulatory legs relatively shorter (P5 length/ CL = 0.52), upper margin of P5 merus distinctly convex in B. serenei ; Fig. 3F View Fig ); (6) in the male pleon, the lateral margins of somites 4 and 5 are only slightly concave, and somite 6 is subquadrate and relatively shorter in B. metiguinotae ( Figs. 4C View Fig , 6A View Fig ) (vs. lateral margins of pleonal somites 4 and 5 much more pronouncedly concave, pleonal somite 6 sub-rectangular and relatively longer in B. serenei ; Fig. 4D View Fig , cf. Guinot, 1976: fig. 31B); (7) the distal tip of the G1 is slightly narrow, with seven short, hooked spines on the dorso-lateral margin, sternal surface smooth, and the most distal part covered by numerous long and simple setae in B. metiguinotae ( Fig. 6C, D View Fig ) (vs. G1 distal tip more blunt, with numerous short, hooked spines on the dorso-lateral margin and sternal surface, and the most distal part with several long plumose setae in B. serenei ; cf. Guinot, 1976: fig. 34A, B); and (8) G2 terminal segment slightly longer ( Fig. 6E View Fig ) (vs. G2 terminal is slightly shorter in B. serenei ; cf. Guinot, 1976: fig. 34C).