Pagurapseudopsis sp.

Kong, Chim Chee, 2024, A synopsis of the Tanaidacea (Crustacea: Peracarida) of Singapore, with a review of tanaidacean diversity in Southeast Asia and the South China Sea, Zootaxa 5451 (1), pp. 1-75 : 24

Pagurapseudopsis sp. SG#1

( Figs. 10A–B )

Material examined. Station SG9: 2 damaged specimens, including 1 female with oostegites (KG 13/5 P9.1). Station SG13: 1 damaged specimen (002). Station SG21: 1 incomplete ovigerous female (CR0605-P01-03). Station SG84: 1 ovigerous female (20181009.150), 12 October 2018.

Remarks. Pagurapseudopsididae is a monogeneric family with Pagurapseudopsis as the sole member. Shiino (1963) described the genus and and designated P. gracilipes Shiino, 1963 as the type species. He also identified the simple antenna, the homogenous pereopods and elongated pleopods as important characters of the genus. Other diagnostic features of the genus include the (1) laterally triangular pleonites; (2) pleotelson bearing a pair of lateral lobes; (3) elongated antennule peduncle article-1 with plumose setae on both margins; (4) antenna peduncle with five articles; and (5) rounded cheliped basis. Pagurapseudopsis is currently represented by six species ( Anderson 2023), namely P. gymnophobia ( Barnard, 1935) , P. gracilipes , P. iranica Bacescu, 1978b , P. ceylonica Bacescu, 1981 , P. thailandica Angsupanich, 2001 and P. kochindica Pandiyarajan & Biju, 2017 (in Pandiyarajan et al. 2017), which were all recorded from intertidal to shallow subtidal habitats (up to 28 m) in the Indo-West Pacific. Identification key to all species of the genus, with exception of P. kochindica , was provided in Angsupanich (2001).

The present material from Singapore is most similar to P. gracilipes from Vietnam but (1) has a different cephalothorax shape (ovoid vs. trapezoid); (2) possesses more notches on pereonites 4–6 (3 vs. 2); and (3) does not have the large recurved process on the basis of pereopod-1. Pagurapseudopsis sp. SG#1 is a potentially undescribed species, and is among the largest tanaids in Singaporean waters at 6.5 mm long. Collection data for this species are incomplete for most samples, but available information include estuarine habitats along the Johor Strait including Punggol and Sungei Buloh Wetland Reserve.

Figures

FIGURE 10. Pagurapseudopsis sp. SG#1 ovigerous female, CR0605-P01-03, Singapore: (A) ventral habitus; (B) lateral habitus. Scale bar = 2 mm.