Tetraclita ehsani Shahdadi, Chan & Sari, 2011 Figures 3A, B, 9

Examined material.

Five specimens (BD: 8.37-16.58 mm), LFSc.ZRC-184, Sutrapada, Gir Somnath district (20°50'23"N, 70°28'28"E), 22 December 2019, Gujarat, India, rocky shore, leg. K. Patel.

Diagnosis

(modified from Shahdadi et al. 2011). Shell four-plated, conical, pink (Fig. 3A). Scutum and tergum white. Scutum narrow, external surface bearing faint horizontal striations, 1.5 × higher than wide, adductor muscle pit shallow, seven distinct rostral and four-six lateral depressor crests (Fig. 3B). Tergum long and narrow with ten definite depressor crests, spur long and narrow (Fig. 3B). Maxilla bilobed and setae present on both the lobes (Fig. 9A). Maxillule notched with two large and four small simple setae above notch (Fig. 9B). Mandible with five teeth excluding the inferior angle, 1st tooth separated from the remaining teeth, 2nd and 4th teeth bidentate, 3rd teeth tridentate, 5th tooth small and located close to the 4th tooth (Fig. 9C-E). Mandibulatory palps elongated, superior margin bearing setae (Fig. 9F). Labrum notched, notch shallow, four erect large teeth on each side of the cutting edge (Fig. 9G, H).

Remarks.

The examined specimens in the present study agree with the description given by Shahdadi et al. (2011). Tetraclita ehsani closely resembles T. reni Chan, Hsu & Tsai, 2009, T. achituvi Ross, 1999 and T. rufotincta Pilsbry, 1916, but can be differentiated from these species in the following characters: the tergum is very narrow, with the basal region slightly concave or almost straight vs. the broad tergum that has a strongly concave basal margin in T. rufotincta and T. reni, and the basi-carinal angle is larger (~ 100°) (the basi-carinal angle is smaller in T. reni (80°) and T. rufotincta (73°) (Shahdadi et al. 2011).

Worldwide distribution.

This species has been reported from the Gulf of Oman in Iran (Shahdadi et al. 2011) and from northwest India (Tsang et al. 2012).

Distribution in India.

This species has been reported from Gujarat (Tsang et al. 2012; present study). It is not found in the region further south of Gujarat and was confirmed to be absent in Mumbai and southern India (Tsang et al. 2012).