Opisthacanthus pauliani, Lourenço & Goodman, 2008

Lourenço, Wilson R. & Goodman, Steven M., 2008, Scorpions of the Réserve spéciale d’Ankarana, Madagascar, with particular reference to cave-dwelling animals and the description of two new species (Arachnida, Scorpiones), Zoosystema 30 (3), pp. 665-679 : 673-677

Opisthacanthus pauliani n. sp.

( Figs 5-7)

MATERIAL EXAMINED. — Madagascar. Antsiranana Province, Réserve spéciale d’Ankarana, grotte d’Ambatoharana, 30 m from the entry, XI.1949, J. Millot leg., 1 ♂ holotype, 1 ♂ paratype ( MNHN).

DIAGNOSIS. — Medium size scorpions: male 52 mm in total length. Coloration yellowish to slightly reddishyellow, with some dark zones on pedipalp carinae.Pectines with 7-7 teeth in males. Hemispermatophore as in Figure 6D . Male genital operculum large and slightly heart-like shaped ( Fig. 6C ). Trichobothrial pattern of type C, orthobothriotaxy.

A

The new species can be distinguished from O. madagascariensis and the other Malagasy species of Opisthacanthus by the following characters: 1) a very much paler general coloration; 2) reduction of the median and lateral eyes of about 25% of their size; and 3) hemispermatophore with the distal lamina shorter than in O. madagascariensis and not as enlarged.

ETYMOLOGY. — Patronym in honour of the late Prof. Renaud Paulian, who devoted many years of his life to the study of numerous aspects of the Malagasy fauna. He was of paramount importance in launching the modern era of zoological studies on the island.

DESCRIPTION

(based on ♂ holotype and ♂ paratype) Coloration

Basically yellowish with some dark zones on pedipalp carinae ( Fig. 5). Carapace yellowish with two slightly reddish zones laterally; median and lateral eyes surrounded with dark pigment.Tergites yellowish. Metasomal segments yellowish, with reddish zones on dorsal carinae and dorsal furrow of segments II to IV; vesicle pale yellow; aculeus reddish. Chelicerae pale yellow; fingers yellowish with pale reddish teeth. Pedipalps yellowish to reddish-yellow; most carinae dark. Venter and sternites yellowish; pectines and genital operculum pale yellow; legs yellowish with some internal carinae reddish.

Morphology

Carapace with some rare thin granulations laterally and with punctation; almost smooth; furrows shallow. Anterior margin with a strong concavity reaching the level of the second lateral eye ( Fig. 6A ). Median ocular tubercle flattened and almost in the center of the carapace; median eyes moderate, separated by less than one ocular diameter; three pairs of lateral eyes. Sternum pentagonal, wider than long ( Fig. 6C ). Genital operculum large formed by two semi-oval plates slightly heart-like shaped. Tergites with only a vestigial median carina, and with some minute granulations; almost smooth and with several punctations. Pectinal tooth count 7- 7 in male holotype and male paratype. Sternites smooth and shiny; VII acarinate with several punctations. Metasomal segments I to V longer than wide, with some rare and thin granulations. All carinae weakly marked in segments I-IV; segment V rounded with some spinoid granules on the ventral surface. All segments with weak setation. Telson with a pear-like shape; smooth and covered with strong setation ( Fig. 5). Pedipalps: femur with dorsal internal, dorsal external, ventral internal, and ventral external carinae strong, tuberculate; dorsal face with very thin granulation; ventral face with some minute granulations, almost smooth; internal face moderately granulose. Patella with internal and external faces moderately granulated; dorsal and ventral faces smooth and lustrous; dorsal internal, dorsal external, ventral internal, ventral external, and external carinae strong; other carinae less wellmarked. Chela moderately to strongly granular on internal and external faces; dorsal marginal, external secondary, ventro-internal and ventral median carina strong; other carinae less well-marked. Chelicerae typical of Scorpionoidea ( Vachon 1963); teeth weakly sharp ( Fig. 6B ). Trichobothriotaxy type C ( Fig. 7 ); orthobothriotaxic ( Vachon 1974). Legs: tarsi of legs III and IV with two prolateral and two retrolateral spines, surrounded by a few long setae. Spurs moderate. Hemispermatophore has the distal lamina short and moderately enlarged, as in Figure 6D .

Ecology and distribution

In contrast to O. milloti n. sp., O. pauliani n. sp. was found inside the cave, and probably is an obligate cave-dwelling animal. Th is species is only known from the type locality.

KEY TO THE MALAGASY SPECIES OF OPISTHACANTHUS

Note: the stability of the characters used in the key have been demonstrated in the study by Lourenço & Goodman (2006), in which a few hundreds specimens have been examined.

1. Adult scorpions with 52 to 68 mm in total length ...................................................... 2

— Adult scorpions with 35 to 45 mm in total length ...................................................... 4 2. Coloration reddish-brown to dark brown or globally blackish .................................... 3

— Coloration globally yellowish to pale yellow ...................................... O. pauliani n. sp.

3. Coloration reddish-brown to dark brown ....................................... O. madagascariensis

— Coloration globally blackish, including vesicle; blackish spots on pectines and genital operculum ...................................................................................................... O. piceus

4. Coloration yellowish to reddish-yellow .................................................... O. lucienneae

— Coloration dark; reddish-brown to dark brown .......................................................... 5

5. Female genital operculum with an almost oval-shape, and without any incision in the base ............................................................................................................................ 6

— Female genital operculum heart-like shaped with a small incision in the base ................ ................................................................................................................. O. maculatus

6. Sternite VII without carinae ................................................................... O. darainensis

— Sternite VII with four moderate carinae .............................................. O. milloti n. sp.

Figures

FIG. 6. — Opisthacanthus pauliani n. sp., ♂ holotype: A, carapace; B, chelicera; C, ventral aspect, showing coxapophysis, sternum, genital operculum, pectines and sternite III; D, hemispermatophore, external aspect. Scale bars: 2 mm.

FIG. 7. — Opisthacanthus pauliani n. sp., ♂ holotype, trichobothrial pattern: A-C, chela dorso-external, external and ventral aspects; D, femur, dorsal aspect; E, fixed finger, internal aspect; F-H, patella, dorsal, external and ventral aspects; I, cutting edge of movable finger with rows of granules. Scale bars: 2 mm.