Visayax estampadori, Mendoza & Ng, 2008

Mendoza, Jose Christopher E. & Ng, Peter K. L., 2008, New Genera And Species Of Euxanthine Crabs (Crustacea: Decapoda: Brachyura: Xanthidae) From The Bohol Sea, The Philippines, Raffles Bulletin of Zoology 56 (2), pp. 385-404 : 395-398

publication ID	https://doi.org/ 10.5281/zenodo.5340846
persistent identifier	https://treatment.plazi.org/id/0E16272E-FF8A-FF8A-FC2A-FCB2FE4BF90C
treatment provided by	Diego
scientific name	Visayax estampadori
status	sp. nov.

Treatment

Visayax estampadori View in CoL , new species

( Figs. 5 View Fig , 6 View Fig , 9C View Fig )

Material examined. – Holotype: 1 male (6.7 × 4.6 mm) (NMCR- 27509), Station B17, reef wall with small caves, 3–21 m, 9°37.5'N

123°46.9'E, Bingag, Panglao Island, coll. by Panglao 2004 Marine Biodiversity Project, 19 Jun.2004.

Paratype: 1 female (6.1 x 4.4 mm) ( ZRC 2008.0755 View Materials ), small as holotype ; 1 male (4.5 × 3.3 mm) ( ZRC 2008.0220 View Materials ), Station B 21, reef wall with small caves, 20–21 m, 9°37.2'N 123°46.4'E, Napaling , Panglao Island , coll. by Panglao 2004 Marine Biodiversity Project, 24 Jun.2004 GoogleMaps .

Description. – Carapace ( Fig. 5A View Fig ) broader than long; regions more or less defined; 1M, 2M and 2F raised, distinct from each other, 2M culminates in a large dorsally projecting tooth; sections of branchial region—3L, 4L and 5L—raised into dorsally-projecting tubercles; 3M and 1P distinct, 4M indistinct, cardiac region raised; entire dorsal surface finely granulose or pitted, limited and shallow reticulate patterns formed in mesogastric and cardiac regions; suborbital region eroded with several small depressions; subhepatic and pterygostomial regions with low granules. Front relatively narrow, about 0.3 times carapace width; slightly deflexed ventrally; bilobed, lobes separated by wide V-shaped cleft which continues into frontal region as a thin fissure, then a groove; lobes broadly triangular, bluntly tipped, continuing laterally toward, but not meeting, supraorbital margin, separated from it by short groove. Supraorbital region finely granulose; margin slightly crenulate, relatively short, not clearly meeting anterolateral margin, without distinct external orbital tooth. Suborbital margin slightly crenulate, outer edge connected to anterolateral margin by a ridge consisting of fused granules. Orbits small, width about 0.1 times carapace width; eyestalks short, distal edge with cornea lined with small, toothlike granules; corneas well developed. Anterolateral margin strongly arcuate, feebly cristate, granulose, serrated; anterior-most part not meeting supraorbital margin but curving into pterygostomial region where it eventually disappears close to anterolateral corner of buccal cavity; posterior end with a large, dorsally directed tooth at junction with posterolateral margin. Posterolateral margin gently concave, last ambulatory leg coapted against this concavity. Junction with posterior carapace margin defined by a large, granular, upwardly and outwardly projecting tooth; posterior carapace margin slightly concave.

Antennules ( Figs. 5C View Fig , 6A View Fig ) folding almost transversely. Basal antennal segment large, subrectangular, granulose, occupying entire space between antennular fossa and internal orbital angle, orbital hiatus completely filled; long flagellum arising from distal margin, almost reaching outer edge of orbit. Ventral edge of epistome ( Fig. 6C View Fig ) slightly undulate, central region concave, lateral regions with slight depressions. Endostome without any discernible ridges.

Outer surface of third maxilliped ( Figs. 5B View Fig , 6B View Fig ) granulose, eroded. Merus subquadrate, median length about half that of ischium, with 2 shallow depressions on either side of a submedian, granular ridge; margins with small granules, anterior and external margins slightly concave, internal margin straight; anteroexternal angle subauriculiform. Ischium subrectangular, inner margin with granules and short, stiff setae; with deep, longitudinal median sulcus, with smaller longitudinal depression anterolateral to it, adjacent to anteroexternal margin; separated from basis by distinct suture. Exopod finely granulose, tapering toward distal end which almost reaches anterior edge of merus, flagellum long.

Surface of male thoracic sternum ( Fig. 5B View Fig ) granulose, eroded; with a large, distinct, granule-filled depression just anterior to telson of abdomen, no discernible suture within, smaller depressions seen on either side of abdomen; anterior region relatively elongate. Sternites 1 and 2 completely fused into triangular plate, separated from sternite 3 by deep transverse suture. Sternites 3 and 4 partially fused, with partial suture seen near anterior edge of cheliped coxae. Abdominal cavity deep, sternal condyle on sternite 5 slightly nearer to suture with sternite 4, abdomen reaching to imaginary line joining posterior edge of cheliped coxae.

Chelipeds ( Fig. 5A, D View Fig ) similar, subequal. Fingers shorter than palm, cutting edges with 4 or 5 teeth, tips pointed. Dactylus slightly curved, with three rows of granules, continuing distally as ridges and separated by shallow grooves along its length, base granulose. Fixed finger slightly deflexed with 2 rows of granules continuing as ridges and broad submarginal groove continuing from palm. Palm outer surface eroded in faintly reticulate pattern, upper margin irregular, wedge-like and granulose, lower margin slightly convex and granulose; inner surface relatively smoother, with fewer and smaller granules. Carpus short, dorsal and ventral surface eroded, inner distal angle with low triangular tooth. Inner surface of fingers, palm and carpus coapted against anterolateral margin of carapace. Merus granulose, slightly longer than carpus, with rectangular ventro-distal tooth apposed against carpus.

Ambulatory legs ( Figs. 5A View Fig , 6E View Fig ) relatively short, first leg longest, coxa-to-dactylus length about 0.9 times carapace width, sparsely setose. Merus subrectangular, subtriangular in cross-section; anterior and posterior edges lined with granules; dorsal surface finely granular. Dorsal surface of carpus rugose, with row of pointed granules on irregularly serrated anterior edge. Propodus subrectangular, rugose, anterior and posterior edges serrated in most legs. Dactylus slightly curved, dorsal surface and edges covered with small spines, short setae; terminates distally in curved chitinous claw.

Male abdomen and telson ( Fig. 6D View Fig ) granulose, eroded; central regions of segments raised. Telson rounded; lateral margins convex. Segment 6 subquadrate, about 1.5 times length of telson, lateral margins straight. Segments 3–5 completely fused, very faint trace of suture between fourth and fifth segments; lateral margins markedly concave at level of fifth segment, widening gradually towards base of third. Segment 2 subtrapezoidal, segment 1 subtrapezoidal without transverse ridge.

Gonopod 1 ( Figs. 6F, G View Fig ) long and slender, mostly straight, curving outward and tapering distally; distal aperture subterminal; several long, thick and stiff simple setae located subdistally behind aperture; basal external region with row of stiff simple setae, surrounded by finer setae.

Live colouration. – The carapace and pereiopods ( Fig. 9C View Fig ) have a pinkish-white basal colouration. The region immediately surrounding the anterior portion of 3M (protogastric) and the central portion of cardiac region are dark purplish-red; while the regions adjacent to the anterolateral and posterolateral margins, as well as the groove dividing the gastric and branchial regions are light pink; all other regions are in varying tones of reddish-orange. The chelipeds and ambulatory legs are basically light pink and variably mottled with reddish-orange. There are also gradual transitions between the background colour and the darker mottlings, especially on carapace and chelipeds.

Etymology. – This species is named after Eulogio Estampador, a highly respected Filipino carcinologist, for his work on the crab fauna of the Philippines.

Remarks. – The similarities shared by Visayax estampadori , new species, and V. osteodictyon , new species, are discussed in the Diagnosis and Remarks for the genus. Visayax estampadori can be distinguished from V. osteodictyon primarily by the very faint reticulation of the carapace and pereiopod surfaces ( Fig. 5A, D View Fig ), which is very distinct in the type species ( Figs. 3A, D View Fig , 4C, E View Fig ). This reticulation is apparently not age- or size-related as the holotypes of the two species are almost the same size. Furthermore, the reticulate pattern is already distinct in smaller individuals of V. osteodictyon and thus it is a good character for telling the two species apart. In addition to this, V. estampadori can be distinguished from V. osteodictyon by its relatively straighter front ( Fig. 5A, C View Fig ) (vs. more deflexed ventrally in V. osteodictyon , Fig. 3A, C View Fig ); the larger tubercles in the branchial region of the carapace ( Fig. 5A View Fig ) (vs. smaller, Fig. 3A View Fig ); the straight central region of the epistome ( Fig. 6C View Fig ) (vs. slightly convex, Fig. 4D View Fig ); the broader basal antennal segment, which reaches up to the antennulary fossa ( Fig. 6A View Fig ) (vs. narrower, does not reach up to antennulary fossa, Fig. 4A View Fig ); the lack of a pigmented patch on the lower surface of the chela ( Fig. 5D View Fig ) (vs. present, Fig. 3D View Fig ); and by having a larger terminal opening and more subdistal setae—ca. 25—in the G1 ( Figs. 6 View Fig F-G) (vs. smaller terminal opening, less subterminal setae: ca. 16, Fig. 4F–G View Fig ).

Visayax estampadori is so far known only from the type locality, Panglao Island, in the Bohol Sea, central Philippines. It is sympatric with V. osteodictyon and Rizalthus anconis having been collected from the same locality, on a reef wall at a depth ranging from 3 to 21 m.