Rapipontonia galene ( Holthuis, 1952 )

Marin, Ivan, 2009, A review of the pontoniine shrimp genus Rapipontonia Marin, 2007 (Decapoda: Caridea: Palaemonidae), with the description of a new species from the Indo-West Pacific, Zootaxa 2289, pp. 1-17 : 6-8

Rapipontonia galene ( Holthuis, 1952)

( Figs. 3 )

Periclimenes galene Holthuis, 1952: 62 –64, fig. 24 [type locality – Ambon, Menado]. Periclimenes galene . – Bruce, 1976: 12, figs. 3,4; 1996: 232; Fransen, 1994: 122; Bruce & Coombes, 1995: 129. Rapipontonia galene . – Marin, 2007: 777.

Material. Holotype female ( RMNH D9038), Pacific Ocean, Indonesia, Ambon pier 0–2 m, Snellius Expedition, 6 May 1930; and 2 syntypes ( RMNH D9037), Eilandje bij Menado, 25 Sept. 1930.

Other material. 3 immature specimens ( RMNH D42851), Indian Ocean, Seychelles, St. Joseph atoll, NW rim; SEY 753, NIOP-E, Sta. 753, 5º24’S 53º19’E; reef slope, 10 m., on hydroids, 26 July 1992; coll. Fransen; 1 juv. (or young male) ( RMNH, D 42879), Indian Ocean, Seychelles, St. Joseph atoll, NW rim; SEY 753, NIOP-E, Sta. 753, 5º24’S 53º19’E; reef slope, 10 m., on hydroids, 26 July 1992; coll. Fransen; 1 immature female ( RMNH D48165), Pacific Ocean, Indonesia, Mollucas, Ambon, Leitimur, Ambon Bay, outer bay, Tg. Benteng (=Galghoek); Sta. RBE 0 5, 0 9 June1990, 2– 3 m, on hydroid, coll. Fransen; 1 juv (or immature female) ( RMNH D48424), Philippines, Cebu strait, Olango Channel, E side of Olango Is., Sta. CEB. 0 1, 10º15,54’N 124º04,17’E, gentle reef slope, 0 4 Nov. 1999, 10m, on dead Cirripathes with overgrowing colonies of Didemnium, Nemanthus , and hydroids, coll. C. Fransen; 1 ovigerous female ( RMNH D48423), Philippines, Cebu strait, W. of Bohol, N side of Cabilao, NE of Looc, Olango, Sta. CEB. 0 9, 9º53.59’N 123º46,92’E, overhanging wall with caves, 12 Nov. 1999, 10m, on hydroid, coll. C. Fransen (photo 9/28–34); 1 male (QM W28359), Pacific Ocean, Hawaii, off Ulua Beach, Kihei, Maui, 20º47’N, 156º28’W, 10 m, on Pennaria disticha (Goldfuss, 1820) (Hydroidea, an introduced species), 0 7 Oct. 2005, coll. M. Roberts.

Diagnosis. Small epigastric tooth divided from carapace by undistinguished suture. Rostrum ( Fig. 3 A) slender, rostral formula 1+6–7/0; proximal rostral crest with 4–5 large teeth; distal part of rostrum slender, with second dorsal tooth separated from subapical tooth by distinct gap. Antenna ( Fig. 3 B) with distolateral margin of basal segment bearing sharp distolateral tooth and rounded median lobe. First pereiopod slender, fingers with spoon-like tips ( Fig. 3 D). Second pereiopods ( Fig. 3 E, G) smooth, equal in size both in females and males, reaching to the distal margin of antennular peduncle; merus about 10 times longer than wide, carpus about 7 times longer than maximal width, flaring distally, palm ( Fig. 3 F, H) about 3 times longer than wide, ratio of merus: carpus: propodus: dactylus is 4.5: 3.5: 2: 1. Third pereiopod with distoventral margin of propodus bearing 2–3 long unpaired and a pair of long distoventral spines ( Fig. 3 G); most proximal third unpaired spine, if present, about twice shorter than the next one ( Fig. 3 I).

Remarks. All examined specimens agree well with previous descriptions ( Holthuis, 1952; Bruce, 1976). The species clearly differs from the remaining species of the genus by the slender, second pereiopod which are equal in both sexes; with carpus about twice longer than propodus and fingers about half of palm length.

Coloration. The description of alive coloration presented on the label of the specimen (RMNH, D48423): “ Transparent with oblong dorsal internal stripe; with brown line from antennules to telson; several white chromatophores on carapace and abdomen; eyestalk with red line ”.

Hosts and distribution. The species is known throughout numerous localities in the Indo-West Pacific (Eastern Africa, Seychelles, Vietnam, Philippines, Indonesia, Comoro Islands, Japan, Australia) ( Holthuis, 1952; Bruce, 1976, 1996; Fransen, 1994; Bruce & Coombes, 1995; present study) and Hawaii (present study). Known in associations with the hydroids Lytocarpia sp., Aglaophenia sp. and Pennaria disticha (Goldfuss, 1820) (Cnidaria, Hydroidea, Thecaphora) ( Bruce, 1976, 1996; present study)

Figures

FIGURE 3. Rapipontonia galene (Holthuis, 1952), female (RMNH, D 48423): A—carapace and rostrum, lateral view; B—antennular peduncle, dorsal; C—basal segments of third maxilliped; D—chela of first pereiopod; E, G—second pereiopods; F, H—same, chela; I—grasping mechanism of third pereiopod; J—ventral spines on propodus of third pereiopod. Scale bar: 1 mm.