Lacertopontonia chadi Marin, 2011

Fransen, Charles H. J. M. & Reijnen, Bastian T., 2012, A second discovery of Lacertopontonia chadi Marin, 2011 (Crustacea: Decapoda: Palaemonidae), with remarks on its systematic position, Zootaxa 3437, pp. 43-50 : 44-46

Lacertopontonia chadi Marin, 2011

(figs. 1, 2)

Lacertopontonia chadi Marin, 2011: 57 –68, figs 1–7.

Material examined. 1 ovigerous female (pocl. 5.1) RMNH. CRUS.D.53857, 1 male (pocl. 3.8) OUMNH.ZC.2012- 01-0064; stn SEM.14, Malaysia, Sabah, Ligitan Island, Ligitan 2, 04º09’35.8”N 118º52’22.2”E; 3 Dec. 2010; depth 15 m; inside Lopha cristagalli encrusted by a red sponge; collected by Charles H.J.M. Fransen. Paratypes: 1 ovigerous female (pocl. 5.0), 1 male (pocl. 4.0) RMNH. CRUS.D.54783; Australia, Great Barrier Reef, Lizard Island, lagoon, Channel, st. LI10–022, 14° 41.435 S 145° 27.912 E; 28 Aug. 2010; depth 14–15 m; in wash-out from bivalve Lopha cristagalli growing on sea whip; collected by Chad Buxton.

Comparison with type-material. The Sabah material generally corresponds to the type description by Marin (2011). Several dissimilarities were noted in the present material.

The cutting edge of the fixed finger of both major and minor second pereiopods in both the Sabah male and female have the posteriormost tooth shallow and rounded, with many small simple denticles (fig. 1A, B). In the paratype male and female in the RMNH collections this feature is also present although erroneously described and figured by Marin (2011: 67, figs. 5D, E; 6B-F) as: “fixed finger (pollex) with two triangular acute teeth in proximomedial part”. Figure 1 C shows the chela of the second pereiopod of the male paratype, originally figured by Marin (2011: fig. 6d).

The corpus of the dactylus of the third ambulatory pereiopod of the Sabah specimens, as well as the paratypic specimens, have fewer setae than drawn by Marin (2011: fig. 5g). A small, acute, forward directed tooth on a shallow basal protuberance is present on the proximal part of the flexor margin of the corpus of the dactylus (fig. 2A, B). In the paratype material an indistinct tooth on a shallow basal protuberance is visible in the third pereiopod of the ovigerous female, but not illustrated or mentioned in Marin (2011).

In the fifth pereiopod, a rather small shallow angular tooth on a shallow basal protuberance is present on the proximal part of the flexor margin of the corpus of the dactylus (fig. 2C). In the male paratype specimen such a tooth is not present although a shallow basal protuberance can be observed (fig. 2D). The distoventral part of the propodus bears a small articulating spine (fig. 2C). Such a spine has also been observed in the paratype material (fig. 2D), but not illustrated or mentioned in Marin (2011).

Telson with 3 pairs of submarginal dorsal spines and two pairs of distal spines (fig. 1D). The distalmost pair of dorsal spines can also be viewed as a subdistally and submarginally placed lateral pair of spines from the 3 distal pairs of telson spines as described for most Pontoniinae .

The exopod of the uropod is distinctly longer than the endopod. The exopod lacks the distolateral tooth but bears a small mobile distolateral spine. This distolateral mobile spine is present in the paratypes as well (fig. 2E), which contradicts the original description and figure ( Marin 2011: 67, fig. 3D, F).

Colouration. As described for type specimens from Lizard Island.

Host. The infestation rate of the shrimp seems low in the Semporna area. After finding the present specimens in Lopha cristagalli , about 30 specimens of the host were collected and inspected for the presence of shrimps, without any success.

Figures

FIGURE 1. Lacertopontonia chadi Marin, 2011. A, B, D, male (RMNH. CRUS. D. 53857), Semporna; C, male paratype (RMNH. CRUS. D. 54783), Lizard Island. A, second pereiopod, left major chela, median view; B, second pereiopod, right minor chela, median view; C, second pereiopod, right major chela, median view; D, telson. Scale bar = 1.0 mm.