Albunea groeningi Boyko, 2002

Yogesh Kumar, J. S., Boyko, Christopher B., Arun, G., Geetha, S. & Raghunathan, C., 2020, A new distribution record of Albunea groeningi (Crustacea: Anomura: Decapoda: Albuneidae) from the Digha Coast, West Bengal, India, Zootaxa 4766 (4), pp. 588-592 : 590-591

Albunea groeningi Boyko, 2002 ( Figs. 1 , 2 )

Albunea groeningi Boyko, 2002: 296–303 , figs. 96, 97 (full synonymy).— Markham & Boyko, 2003: 1, 2, 4, 5.— Boyko, 2007: 181.— Osawa & Fujita, 2007: 137–139, fig. 5f, g.— Boyko & McLaughlin, 2010: 140 .— Osawa et al., 2010: 12–14, figs. 5–6.

Material examined. ZSI/ MARC A6785, 2 males, coll. J. S. Yogesh Kumar, 17 July 2019, Digha coast, West Bengal, India, 21°36.950’N, 87°30.264’E.

Distribution. Japan (type locality: Honshu Island), Taiwan, Philippines, Singapore, Malaysia, Vietnam, Australia (Queensland, Victoria) and India (present study).

Remarks. The key morphological characteristics of the specimens in identifying them as A. groeningi are as follows: CG11 absent, and anterior margin of carapace with 8–11 spines on both sides of ocular sinus; CG1 to CG10 show the same pattern as in the holotype. The rostrum, triangular ocular plate and distal peduncular segment with cornea at tip are present. The pereopod III dactylus has the base to heel deeply concave, heel to tip with a broadly concave indent and slightly concave indent present at the midpoint of the proximal margin, tip acute, and tip to base smoothly convex. The telson of the male specimen is elongated with the length greater than width and the distal tip rounded with a median indentation. Additional measurements of a male 6.30 mm CL and 7.43 mm CW include: right pereopod I length 4.50 mm, width 5.48 mm; pereopod II length 5.46 mm, pereopod III length 6.87 mm, telson length 2.85 mm, abdominal somite I dorsal length 7.74 mm, abdominal somites II–VI dorsal (combined) length 5.71 mm ( Figs. 1 , 2 ).

Albunea groeningi is very similar to A. symmysta and A. okinawaensis Osawa & Fujita, 2007 but all three species can be distinguished on the basis of their carapace groove pattern, pereopod I–III shape and telson structure (see Osawa & Fujita 2007). The present specimens of A. groeningi are smaller than many previously reported; males are known up to 14.4 mm CL. The species was previously reported from southern Japan southward to Western Australia and Victoria down to 45.7 m depth ( Serene & Umali 1965; Boyko 2002) but was unknown west of this range. In general, albuneids are uncommonly collected and poorly known due to their peculiar burrowing habits ( Boyko 2002; Osawa & Fujita 2012). Only three species ( A. symmysta , A. occulta , A. thurstoni ) were previously reported from the Indian coast ( Henderson 1893; Serene & Umali 1965; Subramoniam & Panneerselvam 1985; Roy & Mitra 2010; Marimuthu et al. 2015; Reshmi et al. 2017; Kumar et al. 2018) and A. groeningi is newly recorded from India, specifically from West Bengal on the east coast. Additional surveys and taxonomic studies are required to better ascertain the true diversity of sand crabs in India.

Figures

FIGURE 1. Albunea groeningi Boyko, 2002, male CL 6.30 mm. A, dorsal view; B, ventral view; C, carapace and branchiostegite, dorsal view; D, abdominal somites I–VI, and telson of male, dorsal view; E, distal ocular peduncular segments with corneas; F, right pereopod I; G, right pereopod III; H, right pereopod II.

FIGURE 2. Measurements of Albunea groeningi Boyko, 2002, male CL 6.30 mm. 1: carapace;A = 6.30 mm; B, 7.43 mm; C, 1.06 mm; D, 3.33 mm; E, 1.59 mm; F, 47 mm; G, 3.77 mm; H, 3.72 mm; I, 2.76 mm. 2: abdominal somites I–VI; L, 3.29 mm, 2.97 mm, 2.37 mm; M, 5.71 mm; N, 0.774 mm). 3: right pereopod I; J, 4.50 mm; K, 5.48 mm. 4: pereopod III; O, 6.87 mm. 5: pereopod II; P, 5.46 mm. 6: telson; Q, 2.85 mm. Carapace grooves numbered 1–10.