Cryphiops sbordonii, Baldari, Fabiola, Mejía-Ortíz, Luis M. & López-Mejía, Marilú, 2010

Baldari, Fabiola, Mejía-Ortíz, Luis M. & López-Mejía, Marilú, 2010, A new cave species of Cryphiops (Crustacea: Decapoda: Palaemonidae) from Southern Mexico, Zootaxa 2427, pp. 47-54 : 48-52

Cryphiops sbordonii sp.nov.

figs. 2–4

Holotype. Male ( Fig. 2 A), (CL) = 25 mm, 0 1 March 2001; V. Sbordoni leg.; Cueva Chamburro, Las Margaritas, Chiapas, Mexico (16° 25’ 57” N 91° 56’ 40” W); CNCR 25106

Allotype. Female ( Fig. 2 B), CL= 22.5 mm, 0 1 March 2001; V. Sbordoni leg., same locality as holotype; CNCR 25107

Paratypes. 1 female, CL= 12.3 mm; 0 1 March 2001; V. Sbordoni, coll.; CNCR 25108.

Description. Medium sized prawn, maximum total length 54.5 mm. Rostrum short, straight, tip not reaching the distal border of scaphocerite but almost reaching the third article of antennular peduncle; dorsal margin bearing 8 teeth, lack teeth in postorbital position and on ventral margin (fig 2a). Live Cryphiops sbordonii sp. nov. is white, without pigment in the body.

Carapace smooth, maximum length 25 mm, with only antennal spine; branchiostegal groove shallow.

Abdomen smooth, pleura of first three somites broadly rounded (fig. 2a & b). Posteroventral margin of fourth and fifth pleura rounded, all pleura bearing setae on ventral border. Sixth somite 1.5 times as long as fifth.

Eyes reduced, cornea with a small apical black point, this point bearing facets (fig. 2c).

Antennules ( Fig. 3 H) with short stylocerite on the proximal third of first peduncular segment. First antennular segment with acute distolateral spine and concave depression to fit eye. Second antennular segment semi-cylindrical, with sinuous distal margin and lateral row of long setae.

Antennae ( Fig. 3 F) with basicerite bearing short spine on internal margin. Scaphocerite 2.4 times as long as wide, distolateral spine short, widely separated from distal margin of main blade.

Mandibles ( Fig. 4 A) with 3-segmented palp, first and second segments shorter than third segment; incisor process with 6 conical teeth, molar process with 7 wide, rounded teeth on mesial border.

Maxillules ( Fig.4 B) with bilobed palp, distal lobe slender, with one setae on tip, proximal lobe blunt with two thick and short setae; anterior lacinia with six long setae on mesial margin, distal margin with a row of fine setae; posterior lacinia joint with anterior lacinia, straight, distal half covered with setae.

Maxillae ( Fig. 4 C) with scaphognathite bordered with plumose setae, anterior lobe narrower and longer than posterior one; palp without setae, tapering distally, strongly curved inwards; endite bilobed, divided by incision along distal third, both lobes with tuft of setae on the tip.

First maxilliped ( Fig. 4 D) with bilobed endite, bearing three seate along margin, and tuft of setae on surface of distal lobe. Exopod slender, 4.4 times as long as palp, distal third bearing long setae; palp simple, with two thick setae, shorter than endite; caridean lobe large, fused to base of exopod, bearing long, plumose setae all along margin.

Second maxilliped ( Fig. 4 E) subpediform, podobranch present, well developed; endopodite 4-segmented, distal 2 segments oriented mesially, gnathal border with marginal setae and spines and submarginal setae; exopod slender, almost 1.5 time as long as endopod, tip bearing long, plumose setae (fig. 4E).

Third maxilliped ( Fig. 4 F) pediform, slender, reaching beyond basal portion of antennal flagellum; arthrobranch present, well developed; coxa with rounded lateral projection. Endopod 3-segmented, with abundant setae along ventral margin; first segment 1.5 times as long as second segment; second segment as long as third, distal margin ending in nail. Exopod slender, flat, almost the same length as the first segment of endopodite, bearing long setae distally.

First pereiopods ( Fig. 3 A) slender, smooth, with few tufts of setae on both fingers. Palm surpassing distal margin of scaphocerite; palm slightly compressed, as long as dactylus; carpus 1.75 times palm length, 1.12 times merus length.

Second pereiopods ( Fig. 3 B) subequal in size, without spines. Palm semi- cylindrical, 3.3 times as long as wide, with dispersed tufts of setae, 0.8 times dactylus length; carpus 1.19 times palm length, 0.8 times as long as merus; ischium 0.9 times merus length. Fingers not gaping, elongate, cutting margins covered with tufts of setae, fixed finger and dactylus without teeth.

Propodus and dactylus of third pereiopod ( Fig. 3 C) with several short setae. One row of 7 spines on ventral margin. Propodus 3 times length of dactylus, 2.05 times carpus length.

Fourth pereiopods ( Fig. 3 D), sparsely pilose; propodus 3.4 times dactylus length, 1.87 times as long as carpus; with one row of 9 movable spines on ventral margin of propodus, one pair of setae on propodus– dactylus articulation.

Fifth pereiopods ( Fig. 3 E) the longest. Propodus and carpus pilose; one longitudinal row of 12 movable spines, distal 4 close together, 1 spine on propodus–dactylus articulation; propodus 4 times dactylus length, 2.1 times carpus length.

Appendix masculina ( Fig. 3 G) 2 times length of appendix interna, inner margin with 10 pairs of spines.

Telson ( Fig. 4 G) 1.4 times longer than sixth somite, shorter than uropodal rami; bearing two pairs of dorsal spines, first pair in distal fifth, second pair in middle section with a single spine in the middle on left side; posterior margin broadly triangular bearing two pairs of lateral spines, inner pair 5 times longer than external one, with plumose setae between inner spines, center ending in acute tip.

Etymology. This stygobitic shrimp is named in honor of its discoverer, Professor Valerio Sbordoni, who has greatly contributed to the knowledge of the cave fauna of Chiapas.

Habitat. This species lives in the Cueva Chamburro, a cave system situated northeast of Las Margaritas, Chiapas, Mexico. The cave was explored and surveyed in March 2001, during one of the several expeditions led by Prof. V. Sbordoni. Description and topography of this cave have been reported by Pedicone – Cioffi (2004). The whole cave system is about 600 m long, and 90 m deep. From the entrance, located in the bottom of a wide doline, a steep descending passage 60 m deep leads to two galleries.

The main gallery develops for around 400 m south-eastwards, housing series of rock pools and, in most of its development, a stream ending in a siphon. As reported by Prof. V. Sbordoni, shrimps have been collected along the stream, swimming in rather deep waters.

Figures

FIGURE 2. Cryphiops sbordonii sp. nov. A, lateral view from male holotype CNCR 25106. B, lateral view of female allotype with eggs, CNCR 25107. Scale bars: 10 mm.

FIGURE 3. Cryphiops sbordonii sp. nov., male holotype CNCR 25106. A – E, first through fifth pereiopods, respectively; F, distal portion of antennal peduncle; G, appendix masculina on second pleopod; H, distal portion of antennular peduncle. Scale bars: A – E, 5 mm; F – H, 5 mm.

FIGURE 4. Cryphiops sbordonii sp. nov., male holotype CNCR 25106. A, right mandible; B, right maxillule; C, right maxilla; D, first maxilliped; E, second maxilliped; F, third maxilliped; G, telson and uropods. Scale bars: A – E, 2 mm; F – G, 5 mm.