Stenopus hispidus Olivier 1811

Stenopus hispidus (Olivier, 1811)

(Figs. 27, 28)

Palaemon hispidus Olivier, 1811: 666.

Stenopus hispidus.— Latreille, 1819: 71.— Holthuis, 1946: 12. (with references and complete synonomy).— Yaldwyn, 1968: 278.—de Saint-Laurent & Cleva, 1981: 157.—Goy, 1992: 100— Saito et al., 2009: 109.— Goy, 2010: 215. — De Grave & Fransen, 2011: 253.

Material examined. New Caledonia. Lagoon, Aubry Lacomte 241-63, 1903, det. Bouvier 1907, 1 male, 1 female (MNHN-NA 3570).—Lagoon, coll. Bougier 1903, det. Bouvier 1907, 1 male, 1 female ov. (MNHN-NA 3573).— Mission Singer-Polignac, Phares Amedes, Noumea, coll. Salvat, 30.XII.1961, 1 male (MNHN-NA).—Aquarium de Noumea, don. C. Vadon, 17.II.1977, 1 male (MNHN-NA 3489).—Baie de Poya, 21°23’S, 165°04’E, coll. F. Conand, chatutage, 5–12m 10.XII.1982, 1 male (MNHN-NA).—Lagon Sud-Ouest, Campaign No.2. stn 104, Ile Ouen, Baie du Prony, 22°26’S, 166°40’E, 24 m, VIII.1984, 1 female ov. (MNHN-NA).—MUSORSTOM 4, stn CC147, 19°35’S, 163°39.06’E, 43 m, 13.IX.1985, 1 male (MNHN-NA 11990). —Baie de Saint Vincent, coll. M. Kilbriki, chalutage, VIII 1985, 1 male, 1female (MNHN-NA—Baie de Saint Vincent, chalutage, 23.IV.1986, 3 males, 1 female ov. (MNHM-NA).—Lagon Nord-Ouest, Campaign No.12, stn DW916, 20°55.5’S, 164°28.3’E, 13 m, 26.IV.1988, 1 male (MNHN-NA).—Lagon Nord, Campaign No. 13, stn DW1067, 19°55.8’S, 163°52.8’E, 28 m, 23.X.1989, 14 males, 1 female ov. (MNHN-NA).—stn DW1069, 19°59.1’S, 163°52.5’E, 3 m, 23.X.1989, 1 male (MNHN-NA).—stn 1072, 19°50’S, 164°40’E, 20 m, 23.X.1989, 1 male (MNHN-NA).— Chesterfield Islands. CORAIL 2, Plateau des Chesterfield, oust Nouvelle Caledonia, Iles Bellona, VIII.1988, 4 males, 2 females, 1 ov.) (MNHN-NA).— Loyalty Islands. MUSORSTOM 6, stn DW430, 20°21.17’S, 166°07.25’E, 30 m, 17.II.1989, 1 male (MNHN-NA 11989).—Mare Island, reef, 1 male, 1 female (MNHN-NA).

Measurements (mm). Males, PCL: 5.2–11.0; RCL: 7.1–17.5; TL: 44.1–55.8.—Females, PCL: 11.6–15.0; RCL: 16.8–21.5; TL: 44.1–55.8.—Females ov., PCL: 10.0–13.4; RCL: 12.9–17.0; TL: 38.1–47.0.

Distribution. Stenopus hispidus is the only pantropical species in the infraorder Stenopodidea. Previously recorded from the Western Atlantic from Cape Lookout, North Carolina, throughout the Caribbean and Gulf of Mexico to the southern border of Brazil (Williams 1984); central Atlantic from Ascension Island (Manning & Chace 1990); Eastern Pacific from Taboga Island, Panama (Goy 1987, 1992b); and throughout the tropical and warm temperate Pacific (Holthuis 1946).

Coloration. Good descriptions of the color pattern for this species are given by Holthuis (1946) and Yaldwyn (1968). Laboute & Magnier (1987) published a color photograph of Stenopus hispidus from New Caledonia.

Remarks. Stenopus hispidus is a well known species that has become widely recognized as a symbol of tropical marine biodiversity and is not redescribed here. The species has been previously recorded from New Caledonia (Yaldwyn 1968; Laboute & Magnier 1987; Junker & Poupin 2009; Poupin & Junker 2010). The material examined here was collected between 2–43 m which is within the recorded depth range for the species: intertidal waters to 210 m (Holthuis 1946).

From Philippine material, de Saint-Laurent & Cleva (1981) described two juveniles of S. hispidus of 17.0 and 18.0 mm total length and they believed the specimen of 17.0 mm represented the first postlarval stage. The present author has examined over 700 specimens of S. hispidus from all areas of its wide zoogeographical distribution. The smallest first postlarval stage or decapodid (Felder et al. 1985) found in this large sample size was a specimen from Howland Island, 0°48’N, 176°38’W (USNM 25187) measuring 9.6 mm total length and having rudimentary exopods on the pereiopods. The smallest ovigerous female examined was 25.6 mm total length. Eighty-four specimens examined were less than 25.0 mm total length, which is, therefore taken as the approximate size at which sexual maturity is reached for this species. Specimens below this length all exhibit the juvenile characteristics attributed to postlarval stages by Rathbun (1906), Holthuis (1946), de Saint-Laurent & Cleva (1981) and Goy (1990), which include a relatively longer antennule peduncle, rostrum, sixth abdominal pleuron and propodus of the third pereiopod; less spinous carapace and abdomen; and a very large dorsal median projection on the third abdominal pleuron. Within the 84 juveniles examined, 57 specimens, ranging in total length from 9.6– 18.2 mm, had remnants of larval exopods on the pereiopods. Members of the genus Stenopus exhibit extreme plasticity in their larval developmental patterns. This has been demonstrated by laboratory rearings of larvae (Castro & Jory 1983; Goy 1990; Fletcher et al. 1995; Zhang et al. 1997) as well as reported size variations of plankton caught larvae (Gurney 1936; Lebour 1941; Williamson 1976). Due to this plasticity, the actual size at metamorphosis may vary by as much as 9.0 mm depending on the duration of larval development and the nutritional state of the metamorphically competent larvae (Goy 1990). Postlarval differences between Pacific and Atlantic populations of S. hispidus are not yet known.