Pontonides loloata Bruce 2005

(Fig. 28)

Pontonides loloata Bruce, 2005: 367, figs 17-21.

MATERIAL EXAMINED. — Marquesas Is. Nuku Hiva, MUSORSTOM 9, stn CP 1177, 8°45.1’S, 140°15’W, 108-112 m, 25.VIII.1997, 1 ovig. ♀ (cl 2.29 mm) (MNHN-Na 15619).

DISTRIBUTION. — Type locality: Loloata I., Hansa Bay, Papua New Guinea. Previously also known from Japan (Izu Peninsula); 5-9 m. Not previously recorded from French Polynesia.

Pontonides has been found from shallow water less than 100 m depth. The collection depth 108-112 m of the present specimen represents the deepest bathymetric record not only for Pontonides loloata (reported previously from 5-9 m depth in the type locality Loloata I., Papua New Guinea [Bruce 2005], and about 30 m [S. De Grave pers. comm.]), but also for the genus.

REMARKS

The specimen agrees well with the original description and illustrations. The pterygostomian lobe of the carapace is folded inwards on both sides of the carapace, forming a semi-closed “tube”, which is opened at the anterolateral margin of the carapace and extends posteriorly to the anterior fifth of the carapace length. The “mouth” of the “tube” looks like the pterygostomian notch present in Pseudopontonides pricipes (Criales, 1980), which is a key feature distinguishing Pseudopontonides from Pontonides (Heard 1986) and other related genera. However, when the inward folding lobe is stretched, the anterolateral margin is only slightly concave, there is no real sinus such as the pterygostomian notch in Pseudopontonides. Pontonides can be readily distinguished from another close genus Pseudocoutierea Holthuis, 1951 which has also the pterygostomian sinus and been known from the East Pacific, the Carribean and the Eastern Atlantic, by pleurae of the third to fifth abdominal somites being broadly rounded (vs. produced into an elongate narrow process and ending in a sharp spine in the genus Psudocoutierea). Recently, De Grave (2007) published a new species of the latter genus, Pseudocoutierea dotae De Grave, 2007, from the Carribean coast of Panama. It may easily differ from Pontonides loloata by the long rostrum and the rounded distolateral angle of the supraorbital eave (vs. the short rostrum and the blunt distolateral angle of the supraorbital eave in the latter), besides the different pleurae of the third to fifth abdominal somites.

A distinct antennal suture is present on the carapace below the antennal spine and extends posteriorly to the anterior fifth of the carapace length in Pontonides loloata. Bruce (2005) did not mention this suture in the original description and illustration. The lateral margin of the uropodal exopod only bears a minute medial mobile spine and no fixed distal tooth. The eggs are small, egg number is about 80- 100, maximum egg length is 0.43 mm.