On the identities of Pilumnopeus convexus Maccagno, 1936, and P. salomonensis Ward, 1942, from the Indian Ocean, with a note on P. riui Takeda, 2001 (Decapoda, Brachyura, Pilumnidae)

Abstract

The taxonomy of the western Indian Ocean pilumnid crab, Pilumnopeus convexas (Maccagno, 1936) (type locality: Ethiopia) is discussed and the poorly known P. salomonensis Ward, 1942

First record of Pilumnopeus convexus (Maccagno, 1936) (Crustacea, Decapoda, Pilumnidae) from the Indian coast

“…Morphological examination of the newly examined specimens of P. convexus corresponds with previous descriptions of the same species by Barnard (1955), Davie (1989), and Ghory et al (2013). Indeed, the newly collected crabs have hexagonal carapace, bilobed frontal margin, structure of anterolateral teeth, armature of chelipeds and ambulatory legs.…”

“…Indeed, the newly collected crabs have hexagonal carapace, bilobed frontal margin, structure of anterolateral teeth, armature of chelipeds and ambulatory legs. However, the newly collected specimens differ from the previous descriptions of P. convexus (Barnard 1955, Davie 1989, Ghory et al 2013 by the placement of sternite 8 and the morphology of G1. Sternite 8 is not visible in the ventral view of the new specimens, while it is clearly visible in specimens examined by Davie (1989) and Ghory et al (2013).…”

“…Crabs were preserved in 70% alcohol and deposited in the Zoology Museum, Department of Zoology, Faculty of Science, the Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, India with accession number (ZL-AR-CR-100). Terminology used for morphological descriptions follows Ghory et al (2013): carapace length (CL), measured along the vertical median line of the carapace; carapace width (CW), measured horizontally at the widest point of the carapace; and male first gonopod and male second gonopod (G1 and G2, respectively). Morphometric characters were measured in millimetres using digital caliper to the nearest 0.01 mm.…”

“…Pilumnopeus differs from Heteropanope in having the carapace more convex and narrower and rounded in front, and with 8 sternites visible laterally on the male abdomen (Davie 1989). Currently, Pilumnopeus contains 10 well-recognised species (Davie 1989, Ng et al 2008, Ghory et al 2013), but Pilumnopeus convexus (Maccagno, 1936) is taxonomically problematic. This species was originally described from Ethiopia based on 2 female specimens (Maccagno 1936), but later Davie (1989) redescribed P. convexus based on a female lectotype collected from Ethiopia and illustrated the carapace and cheliped of this specimen.…”

“…This species was originally described from Ethiopia based on 2 female specimens (Maccagno 1936), but later Davie (1989) redescribed P. convexus based on a female lectotype collected from Ethiopia and illustrated the carapace and cheliped of this specimen. More recently, Ghory et al (2013) discussed the taxonomy of P. convexus and P. salomonensis Ward, 1942 and assigned P. salomonensis as junior synonym of P. convexus. Pilumnopeus convexus is recorded to date from the coast of Ethiopia (Maccagno 1936), South Africa (Barnard 1955), Red Sea (Apel 2001); Iran Türkay 2012, Naderloo et al 2013); Saudi Arabia and Bahrain (Apel 2001), UAE (Cooper 1997, Apel 2001, and Pakistan Davie 2000, Ghory et al 2013).…”