Amphibalanus amphitrite (Darwin, 1854) Figures 2F, 5

Examined material.

five specimens (BD: 8.29-17.16 mm), LFSc.ZRC-181, on fishing boat surface, Jakhau, Kachchh (23°11.30'N, 68°37.35'E), 21 August 2019, Gujarat, India, sandy shore, leg. M. Doshi.

Diagnosis

(modified from Chan et al. 2009). Shell conical, outer surface smooth, with longitudinal deep-purple striations (Fig. 2F). No horizontal striations on shell surface. Tergum with short, wide spur (Fig. 5). Scutum usually flat, occasionally concave between the apex and the basal margin. Articular ridges prominent (Fig. 5). Maxilla bilobed with dense setae on all margins (Fig. 5A). Maxillule not notched, cutting edge straight, upper and lower margins bearing fine setae (Fig. 5B). Mandible with five teeth, upper three teeth sharp, well developed (Fig. 5C-E). Mandibulatory palp bearing setae on superior margin (Fig. 5F). Labrum with a deep cleft, ca. 13-22 teeth on each side of cutting edge (Fig. 5G, H).

Remarks.

The specimens examined in the present study agree with the descriptions given by Henry and McLaughlin (1975), Chan et al. (2009), and Pochai et al. (2017). Amphibalanus amphitrite closely resembles A. reticulatus (Utinomi, 1967) but differs from the latter in the following characters: the shell plates have only vertical purple striation (shell plates have longitudinal stripes intersected with transverse striations in A. reticulatus: Pochai et al. 2017), the shape of the shell is comparatively less columnar than in A. reticulatus (Pochai et al. 2017).

Worldwide distribution.

This species has been reported from Bermuda and southeast USA to Brazil, Hawaii, California to southwest Mexico, western European waters, Mediterranean Sea, south coast of Africa, Red Sea, Black Sea, Southeast Africa, India (Trivedi et al. 2015), Australia, Indonesia, Singapore, Malaysia, Gulf of Siam in Cambodia (Jones and Hosie 2016), Vietnam (Condor Islands, Tang Trien (South Annam), Cauda Nhatrang, Hongay, Tonkin), the South China Sea, Bohai Sea (China), Taiwan, the Philippines, Japan (South Honshu, Kyushu and Ryukyu Islands) and Vladivostok (Russia) (see review in Henry and McLaughlin (1975)).

Distribution in India.

This species has been reported from Gujarat (Trivedi et al. 2015; Parmar et al. 2018; present study), Maharashtra (Bhatt and Bal 1960), Goa (Desai et al. 2018), Kerala (Nilsson-Cantell 1938), Tamil Nadu (Prasanth and Sureshkumar 2020), Andhra Pradesh (Rao and Balaji 1988), Pulicat Lake (Sanjeeva 2006), Odisha (formerly Orissa) (Mitra et al. 2010), West Bengal (Ramakrishna and Talukdar 2003), and Andaman and Nicobar Islands (Mishra et al. 2010).