Palaemonella rotumana ( Borradaile, 1898 )

Li, Xinzheng, Bruce, Alexander J. & Manning *, Raymond B., 2004, Some Palaemonid Shrimps (Crustacea: Decapoda) From Northern South China Sea, With Descripitions Of Two New Species, Raffles Bulletin of Zoology 52 (2), pp. 513-553 : 534

Palaemonella rotumana ( Borradaile, 1898)

Periclimenes rotumana Borradaile, 1898: 383 .

Palaemonella vestigialis Kemp, 1922: 123 , Figs. 1 , 2 , pl. 3: 2; Holthuis, 1952a: 24, Figs. 2a, b , 3 .

Palaemonella rotumana - Bruce, 1970b: 276, Fig. 2 ; 2002a: 288, 291; 2003: 221; Chace & Bruce, 1993: 89; Müller, 1993: 45; Li, 1996: 226, Fig. 5 ; 1997: 234; 2000: 105, Fig. 115; 2001: 80; De Grave, 2000: 129, Fig. 5 ; Li & Liu, 2003: 160, Figs. 5 c-q.

Material examined. – 1 male, 1 female, CN 92 C-187C, Xincun , coll. X. Li, 27 Mar.1992 ; 1 ovig female, CN 92 C-1405C, Lanmai, Lingao, Hainan Is. , intertidal, coll. X. Li, 9 Apr.1992 ; 1 ovig female, CN 92 C-1419B, Linchang Reef, Hainan Is. , intertidal, coll. X. Li, 10 Apr.1992 ; 1 male, CN R175 B-27, [20º10’N, 110º15’E], 43.5m, corals, AT, coll. F. Sun, 11 Apr.1960 ; 1 male, CN Q55 B-38, [17 30’N, 108 E], sandy mud, 85m, BT, coll. Fengshan Xu, 16 Apr.1959 .

Distribution. – Red Sea and eastern Africa to Hawaii, Eastern Mediterranean.

Remarks. – Commonest species of the genus, distributed from littoral to a depth of 128 meters. It is very close to Palaemonella pottsi ( Borradaile, 1915) . As pointed out and illustrated by Bruce (1970b, 2002a) and De Grave (2000), these two species can be distinguished by the configuration of the dactyl and propodus of the ambulatory pereiopods. In P. rotumana the ventral margin of the dactyl of ambulatory pereiopods is smoothly concave, not biconcave, and the apical ventral propodal spines are long, reaching 0.4-0.5 of the dactyl length, sometimes, this species has an obscure and sometimes a distinct postorbital ridge. In P. pottsi the unguis of dactyl of ambulatory pereiopods is clearly demarcated, the ventral margin of corpus of the dactyl is sinuous or biconcave, and the apical ventral propodal spines are small; the carapace always without supraorbital tubercle. Additionally, P. rotumana is a free-living species, but P. pottsi is associated with crinoids.

Figures

Fig. 1. Coutierella tonkinensis Sollaud, 1914. a, carapace and rostrum, lateral view; b, mandible; c, 1st maxilliped; d, telson; e, tip of telson.

Fig. 2. Exopalaemon orientis Holthuis, 1950. a, carapace and rostrum, lateral view; b, mandible; c, 1st pereiopod; d, 2nd pereiopod; e, 3rd pereiopod; f, same, dactyl and propodus; g, 5th pereiopod; h, same, dactyl and propodus.

Fig. 3. Leander tenuicornis (Say, 1818). a, carapace and rostrum, lateral view, female; b, same, male; c, antennule.

Fig. 5. Leandrites stenopus Holthuis, 1950. a, b, carapace and rostrum, lateral view; c-e, mandible, c, d, right, e, left; f, maxillula; g, maxilla; h, 1st maxilliped; i, 2nd maxilliped; j, 3rd maxilliped.