Neocallichirus vaugelasi, Dworschak, Peter C., 2011

Dworschak, Peter C., 2011, Redescription of Callianassa jousseaumei Nobili, 1904, a junior subjective synonym of Callianassa indica de Man, 1905 with description of a new species of Neocallichirus (Decapoda: Axiidea: Callianassidae), Zootaxa 2746, pp. 1-19 : 10-18

Neocallichirus vaugelasi sp. n.

( Figs 7–10 )

Callichirus jousseaumei . — de Vaugelas, 1984: 529.

[ Callichirus sp. aff. jousseaumei . — de Vaugelas, 1990: 40]

Callianassa jousseaumei . — Dworschak, 1992: 198, figs. 5a–d, 6a–c.

Neocallichirus jousseaumei . — Sakai, 1999: 100, fig. 22e, f [not fig. 22g]; 2005: 179; Tudge et al., 2000: 144 (list). Not Callianassa Jousseaumei Nobili, 1904 (see above).

Type material. Red Sea, Aqaba, J. de Vaugelas coll. with weighted line: HOLOTYPE, ovigerous female (tl 118, cl 23.5), 29 June 1984, NHMW 6980. PARATYPES, 1 male (tl 89, cl 23, left major cheliped missing), 1 female (tl 139, cl 29.8, left major cheliped missing), 1 detached left P1, 4 June 1983, MNHN Th-651; 1 male (tl 105, cl 27.2, right major cheliped and both Mxp3 missing), 18 June 1983, MNHN Th-930; 1 female (cl 24.8, 6th pleomere and tailfan broken off) 4 December 1983, MNHN Th-931; 1 female (tl 108, cl 28, both chelipeds and Mxp3 missing, still entangled in line), (1), 14 April 1984, MNHN Th-932; 1 female (tl 93, cl 25.4, major left cheliped detached, minor attached, 1 additional left cheliped), 14 May 1984, MNHN Th-933; 1 ovigerous female (tl 96, cl 24.9, right major cheliped missing), 11 July 1984 "Aqaba, Hotel, oefs incubateur" MNHN Th-934; 1 detached right major cheliped, MNHN Th-1616.

Description. Carapace ca 0.25 of total length; frontal margin ( Figs 7 A, C, 8A, C, 9B) with three anterior prominences, lateral of which are obtusely angular, appearing uncalcified, overlying inner margins of antennal peduncles; median prominence reaching slightly beyond laterals, forming short obtusely angular rostrum, not extending to cornea.

Carapace lacking rostral carina, with distinct linea thalassinica, and with defined dorsal oval marked posteriorly by deep transverse cardiac furrow, latter extending anteroventrally to either side above linea thalassinica as shallow groove demarcating posterior half of dorsal oval. Frontal margin of carapace continued ventrolaterally beyond intersection with linea thalassinica and onto branchiostegite as thickened oblique ridge terminating at anterior end of prominent rounded hepatic boss. Sclerotised ridge along anterodorsal margin of anterior branchiostegal lobe articulating at junction of oblique ridge and linea thalassinica. Subantennular region of epistome bearing dense tuft of long setae.

Eyestalks ( Figs 7 C, 8C, 9B–D) elongated, triangular, strongly diverging distally, transparent in distal part; cornea dorsolateral in proximal half, small, occupying less then half eyestalk width in dorsal view. Length of exposed eyestalk in dorsal view two times basal width, tips overreaching distal end of basal antennal article.

Antennular peduncle (9E) shorter and heavier than antennal peduncle, terminal article about as long as penultimate and not exceeding midlength of terminal article of antennal peduncle; penultimate and terminal articles of peduncle with ventromesial and ventrolateral rows of long setae; rows of setae continued onto ventral ramus of flagellum; ventral ramus of flagellum slightly exceeding dorsal one, six times length of terminal article of peduncle; dorsal ramus with sparse setae in proximal third, distal fifth comprising tapered tip with dense line of ventral aesthetascs.

Antennal peduncle ( Fig. 9 F) with terminal article slightly longer than penultimate article; short basal article forming slightly produced, setose lip above laterally produced excretory pore; second article longer than first, third article short, visible in lateral view as short triangle ventral to second article and vestigial antennal scale; fourth article elongate, as long as basal, second and third article combined; fifth article narrower, as long as fourth article.

Mandibles ( Figs 8 D, E, 9G, H) with large, three-segmented palp, elongated third article of palp slightly tapered and terminally rounded, concave on external surface, long setae distally on second article and on proximal extensor surface of third, field of short. weakly hooked setae on most of extensor surface of third article, setae heavier and less hooked terminally; incisor process with well defined, terminally corneous teeth on cutting margin, teeth largest on proximal half of cutting margin, internal surface with lip giving rise to molar process proximal to incisor teeth, molar process smooth ( Figs 8 D, 9H) or with about four to five small marginal teeth ( Fig. 8 E), one of which may be spaced proximally on internal margin apart from others.

First maxilla ( Fig. 9 I) with endopodal palp long, narrow, terminal article deflected proximally at articulation and narrowed to terminal tip; proximal endite with very dense fine setation on most of lower mesial margin, terminal lobe with field of large, terminally bifurcate setae; distal endite elongate, proximally narrow, broadening terminally where armed with short stiff bristles; exopodite low, truncate and setose.

Second maxilla ( Fig. 9 J) with endopod acute distally, first and second endites each longitudinally subdivided and densely setose terminally; first endite with low arcuate setose crest across external surface of lower lobe, internal surface fused to broad, rounded, plate bearing long marginal setae; exopod forming large, broad, scaphognathite.

First maxilliped ( Fig. 9 K) with proximal endite narrowly produced, dentiform, marginally setose; distal endite robust, rectangular, mesial half of external surface and margins heavily setose, long dense setae of outer surface overreaching and obscuring stout bifurcate bristles on mesial margin, longest setae terminal, internal surface concave; exopod ovoid, divided by transverse suture marking notch on mesial margin, longest setae in field on external surface and mesial margin proximal to notch; epipod large, posterior lobe broad, anterior end tapered to narrow terminus.

Second maxilliped ( Fig. 9 L) with long, narrow endopod; endopodal merus length about five times width, flexor margin with dense fringe of long, close-set setae; carpus short; propodus slightly arcuate, heaviest distally, greatest width about 1/2 length; dactylus half length of propodus, with terminal brush of stiff bristles; exopod narrow, arcuate, distally overreaching end of endopodal merus, marginally fringed by long setae; epipod small, partial suture subdividing angular terminal lobe (not shown); arthrobranch (not shown) rudimentary.

Third maxilliped ( Figs 7 D, E, 8F, G) without exopod; endopod with long setation on mesial margin, terminal three articles also with long setation on extensor margins; length of endopodal ischiomerus two times width; ischium subrectangular, distinctly longer than broad, proximomesial margin rounded, not strongly produced, internal surface with well defined, longitudinally oriented elevation bearing curved row of sharp denticles (crista dentata); merus subtriangular, slightly broader than long; carpus heavy and subtriangular, with setose lobe on flexor margin, internal surface with dense field of fine setae distally; propodus large, subquadrate, slightly longer than high, internal surface with median field of fine, dense setae; dactylus narrow, slightly arcuate, shorter than height of propodus, terminally with small brush of stiff bristles.

Branchial formula including exopods and epipods as described for first and second maxillipeds above; branchiae limited to single rudimentary arthrobranch on second maxilliped, pair of arthrobranchs on third maxilliped, and pair of arthrobranchs on each of first through fourth pereopods.

First pereopods forming dissimilar chelipeds. Sexual dimorphism not obvious (only one male with attached major cheliped known). Major cheliped ( Figs 7 F, G, 8H, I, 10B, C, H, I) heavy, located on either right (5 specimens) or left (4 specimens) side of body; ischium slender, superior margin sinuous, inferior (flexor) margin with minute denticles in proximal half; merus about two times as long as high, superior margin arcuate, regularly rounded in outline and armed with small denticles; carpus shorter than high, much shorter than palm, superior margin weakly arcuate, proximoinferior margin regularly rounded and with mesially directed denticles in distal half, propodus heavy, length (including fixed finger) distinctly less than twice height, latter greatest proximally, superior margin of palm forming unserrated keel in proximal half, proximal inferior margin lined on internal side by line of submarginal denticles extending onto base of fixed finger; fixed finger with prehensile margin armed with sharp triangular teeth becoming smaller distally; dactylus as long as palm, opposable margin with bilobed subrectangular tooth in proximal half, separated by deep cleft from broad subtriangular tooth distally, terminally with acute hooked tip.

Minor cheliped ( Figs 7 H, I, 8J, K, 9M, N, 10F, G, J, K) well calcified but more slender, less than half as high as major; ischium narrow, unarmed on inferior margin, as long as merus; merus elongately ovoid, twice as long as high, inferior margin unarmed; carpus large, as long as merus, 1.3 times as long as high, markedly exceeding height and length of palm; chela (including fixed finger) narrower than and exceeding length of carpus; palm rectangular, longer than high; fixed finger longer than palm, cutting edge serrated; gape slightly setose; dactylus much longer than palm, cutting edge with low, broad weakly serrated tooth at midlength.

Second pereopod ( Fig. 10 L) chelate, long setae sparsely distributed on inferior margin of ischium, more closely set over most of flexor margin on merus and both margins of carpus, those of superior margin of carpus set in a series of tufts, inferior margin of propodus with similar long setae proximally, progressively reduced in length and stiffened distally, subterminally becoming dense patch of short, stiff bristles; prehensile margins of both fingers corneous, graded from finely micropectinate proximally to smooth distally in both, that of fixed finger obscured by conspicuous tuft of arched bristles on external side near midlength, margins terminated distally in thickened corneous tips of fingers; superior margin of dactylus nearly straight, with long marginal setation proximally, dense patch of short stiff setae and bristles distally; external surface of carpus, propodus and dactylus with scattered patches of short setae.

Third pereopod ( Figs 7 J, 9O) merus broadest at midlength, length three times height; carpus broadest distally, length less than two times height, terminally with patches of long setae overreaching propodus; propodus with proximally-directed lobe of inferior margin not reaching beyond broadest part of carpus, lobe terminally with long distally-directed setae, inferodistal margin with spaced tufts of slightly shorter setae, superior margin with fields of long setae grading to small, patterned tufts of thinner, shorter setae on outer face of article; dactylus tear-shaped, densely setose on external surface, terminating in corneous tip hooked toward external side.

Fourth pereopod ( Fig. 9 P) with merus thicker and longer than carpus; subchelate, inferodistal corner of propodus produced into short fixed finger bearing heavy microserrate setae on external side and short bristles at tip; soft dense setation on outer surface of propodus and dactylus, that of propodus divided into upper and lower fields, densest in lower field where continued onto lower half of internal surface; dactylus terminating in narrow tip hooked toward external side.

Fifth pereopod ( Fig. 9 Q) minutely chelate, opposable surfaces of propodus and minute dactylus excavate, spooned, terminally rounded, forming beak-like chela obscured by dense fields of setation on distal half of propodus and superior surface of dactylus; corneous prehensile lip on fixed finger of chela pectinate.

Abdomen long ( Figs. 8 A, B); dorsal length ratio (along midline) of first to sixth abdominal somites 1: 1.05: 0.9: 0.9: 1: 1.24 (MNHN Th-933). Abdominal somites smooth, glabrous dorsally; first somite narrowed anteriorly, pleuron triangular; second somite with straight anterior margin, posterior margin expanded posterolaterally, with one setal tuft near the posterior margin; third to fifth somites each distinctly shorter than second somite, posterior margins slightly expanded posterolaterally; pleura each with row of plumose setae midlaterally; sixth tergite with fine marginal setation laterally and distinct transverse, posteriorly-facing groove above telson.

Male first pleopod consisting of two articles ( Figs 9 T, U, 10D); second article same length as first, subdivided into two lobes by weak longitudinal furrow, anterior lobe terminally rounded, posterior lobe terminally acute. Female first pleopod simple ( Fig. 10 J), consisting of two articles; terminal article with shoulder at midlength.

Male second pleopod biramous, endopod with small appendix interna and a weakly demarcated appendix masculina (MNHN Th-651, Fig. 10 E) or with no sign of an appendix interna with cincinnuli, the endopod demarcated distally with sutures in a broadly rounded mesial part (appendix masculina?) and a shorter acutely tipped lateral part (MNHN Th-930, Figs 9 V–X). Female second pleopod biramous ( Fig. 10 N, O), endopod with appendix interna.

Third to fifth pleopods ( Fig. 9 Y) forming large, posteriorly cupped fans when coupled at mesial margins of endopods; endopod of each subtriangular, short, stubby appendix interna embedded into mesial margin of endopod ( Fig. 9 Z).

Telson ( Figs 8 A, 9R) 1.2 times as broad as long, broadest at lateral lobes in anterior third, posteriorly truncate to weakly sinuous, posterolateral corners broadly rounded, each bearing tuft of long setae; dorsal surface anteromedially elevated, with shallow sulci on lateral lobes to either side and short transverse line of setae directed posteriorly.

Uropod with angular, posterolaterally-directed lobe of protopod slightly overreaching anterior margin of endopod; endopod broad, rhomboidal, slightly broader than long, posterior margin truncate, nearly straight, dorsal surface with longitudinal carina and small tuft of long setae near posterolateral corner; exopod with anterodorsal plate falling well short of distal endopod margin, distal edge of plate lined with short, thick spiniform setae grading to thinner longer setae of exopod margin; dorsal surface of exopod below plate concave, distal margin with dense fringe of setation, fringe diminished and supplemented by row of short spiniform setae on posterior margin.

Embryos had a diameter between 712 and 785 µm.

Type locality. Aqaba, Red Sea

Etymology. The epithet is dedicated to Jean de Vaugelas (University of Nice, France), who collected the specimens.

Size. Total lengths from 89 to 118 mm, cl 24.8 to 28 mm.

Colour. Not recorded.

Distribution. Red Sea, Aqaba (type locality), Safaga ( Dworschak, 1992).

Habitat. Sublittoral clean sands (down to 10 m water depth), often close to patch reefs. Burrow openings are characterised by mounds (10–15 cm diameter at base, 5–10 cm high)(de Vaugelas, 1984).

Remarks. Neocallichirus vaugelasi sp. n. is morphologically similar to N. jousseaumei in the shape of the tailfan and the shape of the third pereopod propodus. The new species differs from N. jousseaumei in 1) the shape of the eyestalks, which are elongated, have no tubercles and a very small cornea and show no extracorneal pigment; 2) the shape of the major chelipeds, which are a) generally more slender and less massive than in N. jousseaumei and have b) the merus with concave lower denticulate border widest at the midlength (denticulated blade widest proximally in N. joussseaumei ) c) a much longer dactylus, about as long as the dorsal border of the propodus (0.75 as long in N. jousseaumei ), d) sharp triangular teeth on the cutting edge of fixed finger (smooth or with low tubercles proximally in N. jousseaumei ); 3) the shape of the minor cheliped which a) tapers proximally and has b) a much longer carpus than palm (plmi/calmi 0.85–0.61, mean 0.68) [this ratio is 1.27–1.74 (mean 1.5) in the type material (n = 7) and 0.8–1.9 (mean 1.5) in Panglao material (n = 38) of N. jousseaumei , respectively (see Table 1)], c) both cutting edges have denticles (unarmed in N. jousseaumei ) and d) the dactylus is much longer than the palm (dactylus much shorter than palm in N. jousseaumei ).

Note that the male second pleopod figured by Sakai (1999: fig. 22c) was not that of " N. jousseaumei " (= N. vaugelasi sp. n.) because SMF 6780 is listed among the material of N. indicus (= N. jousseaumei ).

Figures

FIGURE 7. Neocallichirus vaugelasi sp. n., female holotype (ovigerous, tl 118, cl 23.5), NHMW 6980. Front in dorsal (A) and lateral (B) view; C, detail of front and eyestalks; third maxilliped in mesial (D) and lateral (E) view (setae omitted); major cheliped in lateral (F) and mesial (G) view; minor cheliped in mesial (H) and lateral (I) view; J, third pereopod in mesial view (setae omitted); K, right uropod in lateral view (flat, setae omitted). Scale is 1 mm.

FIGURE 8. Neocallichirus vaugelasi sp. n., A – D, F – L, female paratype (tl 93, cl 25.4), MNHN Th- 933. E, female paratype (tl 108, cl 28), MNHN Th- 932. Habitus in dorsal (A) and lateral (B) view; C, detail of front and eyestalks; distal part of right (D) and left (E) mandible; third maxilliped in mesial (E) and lateral (F) view; G, major cheliped in mesial view; H, same, fingers in lateral view; I, minor cheliped in mesial view; J, same, propodus and dactylus in lateral view; K, sternite 7 in ventral view. Scale is 1 mm.

FIGURE 9. Neocallichirus vaugelasi sp. n., male paratype (tl 105, cl 27.2), MNHN Th- 930. A, front in lateral view; B, detail of front and eyestalks in dorsal view; eyestalk in dorsal (C) and lateral (D) view; right antennule (E) and antenna (F); mandible in lateral (G) and mesial (H) view; I, right maxillule; J, right maxilla; K, right first maxilliped; L, right second maxilliped; minor cheliped in mesial (M) and fingers in lateral (N) view; O, distal part of third pereopod, mesial face; left fourth (P) and left fifth (Q) pereopod; R, telson; S, left uropod; T, first left pleopod, lateral view; U, same detail of terminus; V, second left pleopod, anterior view; same, distal part of endopod in posterior (W) and anterior (X) view; Y, right third pleopod; Z, same, appendix interna. Setae omitted in A, G – L, O, U, X – Z. Scale is 1 mm.

FIGURE 10. Neocallichirus vaugelasi sp. n., A – E, paratype male (tl 89, cl 23), MNHN Th- 651; F, G, paratype female (ovigerous, tl 96, cl 24.9), MNHN Th- 934; H – O, female paratype (broken, cl 24.8), MNHN Th- 931. A, front in lateral view; B, H, major cheliped in mesial view; C, I, same, fingers in lateral view; F, J, minor cheliped in mesial view; G, K, same, lateral view; L, left second pereopod; D, right first pleopod in lateral view; E, second pleopod, distal part of endopod in posterior view; M, first left pleopod, posterior view; second left pleopod in posterior view; O, same, detail of appendix interna. Setae omitted in E – G, O. Scale is 1 mm.