Leptalpheus denticulatus Anker & Marin, 2009

Anker, Arthur, Pratama, Idham Sumarto, Firdaus, Muhammad & Rahayu, Dwi Listyo, 2015, On some interesting marine decapod crustaceans (Alpheidae, Laomediidae, Strahlaxiidae) from Lombok, Indonesia, Zootaxa 3911 (3), pp. 301-342 : 320

Leptalpheus denticulatus Anker & Marin, 2009

( Fig. 14 )

Leptalpheus denticulatus Anker & Marin 2009: 92 , figs. 1–6, 7a, b, 8; Anker 2010: 38 , fig. 10.

Material examined. Indonesia. 1 male, 2 females ( MZB Cru 4048), western Lombok, Teluk Medana, seagrass flat with sand, mud, some rubble-gravel, burrow, suction pump and digging/sieving, 0.2–0.7 m, 12 May 2014 [male: LB-St3-19, females: LB-St3-08, LB-St3-28]; 1 male ( RMNH. CRUS.D.56743), same collection data [LB-St3-21]; 1 ov. female ( OUMNH.ZC. 2014-10-13), same collection data [LB-St3-16]; 1 female ( MZB Cru 4049), same collection data, associated with Glypturus armatus [LB-St3-07]; 1 female ( RMNH. CRUS.D.56744), western Lombok, Sira, seagrass flat with some muddy areas, burrow, suction pump and digging/sieving, 0.2–0.5 m, leg. D.L. Rahayu et al., 13 May 2014 [LB-St4-39]; 1 male ( RMNH. CRUS.D.56745), same collection data [LB-St4-03]; 1 female ( OUMNH.ZC. 2014-10-14), same collection data [LB-St4-33]; 1 female ( OUMNH.ZC. 2014-10-15), same collection data [LB-St4-34]; 1 female ( MZB Cru 4053), same collection data [LB-St4-41A]; 1 female ( OUMNH.ZC. 2014-10-16), southern Lombok, Teluk Sekotong, seagrass flat, burrow, suction pump, 0.2–0.5 m, leg. D.L. Rahayu et al., 14 May 2014 [LB-St6-34]; 1 female ( MZB Cru 4049), same collection data [LB-St6-15].

Comparative material. Australia. Leptalpheus pacificus Banner & Banner, 1974: 1 male, 1 ov. female ( ZRC 2014.0723), Cocos (Keeling) Islands, Tanjong Puji, burrow (possibly associated with Neocallichirus jousseaumei or Eucalliax aequimana ), leg. P.K.L. Ng et al., 20.III.2011 [CK-03].

Taxonomic account. See Anker & Marin (2009); see also Anker (2010) for additional illustrations.

Habitat. Near-shore sand flats with silt-mud component, often near mangroves or seagrass beds; in burrows of the callianassid mud-shrimp, Glypturus armatus . Depth range: intertidal and shallow subtidal (around 0–5 m).

Distribution. Indo-West Pacific: Vietnam, Philippines, Indonesia (new record), Fiji, French Polynesia ( Anker & Marin 2009; Anker 2010; present study).

Remarks. Leptalpheus denticulatus , a relatively widespread infaunal shrimp, is recorded from Indonesia for the first time. This species appears to be the most common infaunal alpheid in shallow bays of Lombok, which are dominated by sand-mud and seagrass (e.g., Teluk Medana, Sira, Teluk Sekotong). In Teluk Medana, one specimen was found together with its presumed burrowing host, the callianassid mud-shrimp, Glypturus armatus , which is also known to host Jengalpheops rufus (see above).

Leptalpheus denticulatus is easy to be confused with L. pacificus Banner & Banner, 1974 , and in some areas the two species are found in sympatry, for instance, in French Polynesia ( Anker 2010). The only morphological difference between the two species appears to be the shape of the transverse suture (diaeresis) of the uropodal exopod, which has a small mesial tooth in L. denticulatus . This tooth is usually acute or subacute, but in some larger individuals, it is blunt and barely recognisable as a tooth. The colouration, usually pale reddish in L. denticulatus ( Fig. 14 ) vs. pale yellowish in L. pacificus , may provide an additional character to separate these two species ( Anker 2010). Although L. pacificus has not yet been found in Indonesia, its presence in Cocos (Keeling) Islands in the eastern Indian Ocean, southwest of Java (present study, see comparative material), French Polynesia, Hawaii, and possibly Madagascar (Banner & Banner 1974; Anker 2010), suggests that it most likely also occurs in the vast Indonesian Archipelago.

Figures

FIGURE 14. Leptalpheus denticulatus Anker & Marin, 2009: A, B—ovigerous female (cl 10.2 mm) from Teluk Medana, Lombok, Indonesia (OUMNH. ZC. 2014 - 10 - 13), A—dorsal view; B—lateral view; C—female (cl 8.4 mm) from Sira, Lombok, Indonesia (OUMNH. ZC. 2014 - 10 - 15), close-up of the major cheliped in situ, lateral view.