Microeuraphia withersi (Pilsbry, 1916)

Trivedi, Jigneshkumar N., Doshi, Mahima, Patel, Krupal J. & Chan, Benny K. K., 2021, Diversity of intertidal, epibiotic, and fouling barnacles (Cirripedia, Thoracica) from Gujarat, northwest India, ZooKeys 1026, pp. 143-178 : 143

Microeuraphia withersi (Pilsbry, 1916) Figures 3I, J , 12

Examined material.

Five specimens (BD: 3.90-6.01 mm) LFSc.ZRC-161, Kuda, Bhavnagar (21°37.70'N, 72°18.40'E), 21 January 2020, Gujarat, India, muddy shore, leg. M. Doshi.

Diagnosis

(modified from Pilsbry 1916). Specimens depressed, cinnamon-brown with smooth surface, with a large, wide aperture; alae broad with arched, sub-horizontal summits (Fig. 3I ). Scutum thin, triangular, conical, almost twice as long as wide, lower part with fine growth-lines (Fig. 3J ). Articular ridge feebly developed with median lobe, not extending beyond the scutal border. Articular furrow shallow and sharply notched. Tergum narrow, club-shaped, very thick (Fig. 3J ). Cirrus I: anterior ramus (with seven or eight segments) longer than posterior (usually with six or seven segments). Cirrus II: anterior ramus (with seven or eight segments) longer than posterior (usually with six segments). Setae of terminal segment non-pectinated. The carinal lobe narrow, situated high. Maxilla bilobed (Fig. 12A ), group of short spines on the lower edge. Maxillule not notched (Fig. 12B ). Mandible with three large teeth and pectinated lower point with eight spines (Fig. 12C-E ). Mandibulatory palp rectangular (Fig. 12F ). Labrum with broad, nearly straight edge, the middle fold having a series of strong teeth (Fig. 12G, H ).

Remarks.

The specimens examined in the present study agree with the description by Pilsbry (1916). Microeuraphia withersi closely resembles M. depressa and M. permitini , but can be distinguished from the latter based on the following characters: the scutum is comparatively narrow in (scutum is comparatively wide in M. depressa , Poltarukha, 1997), the width to height ratio fluctuates from 0.8 to 1.4 (width to height ratio commonly> 1.5 in M. depressa , Poltarukha, 1997), the basal comb of mandible with eight equally distanced slender spines (1-3 stout spines after third tooth, and a row of small and 2-4 long spines in M. permitini , Shahdadi and Sari 2011), and both the rami of cirri II without finely pectinate setae on terminal segments (both rami of cirri II with finely pectinate setae on terminal segments in M. permitini ; Shahdadi & Sari, 2011).

Worldwide distribution.

The species has been reported from the Philippines ( Pilsbry 1916), the west coast of Sumatra ( Nilsson-Cantell 1921), Indonesia, Singapore, Java, Vietnam, Hong Kong, the South China Sea ( Jones and Hosie 2016), the East China Sea (Zevina and Tarasov 1963), Australia, Madagascar ( Utinomi 1968), and India ( Nilsson-Cantell 1938).

Distribution in India.

This species is reported from Gujarat (present study), Maharashtra ( Nilsson-Cantell 1938; Karande and Palekkar 1966; Wagh and Bal 1974), and West Bengal ( Daniel 1981).

Figures

Figure 3. A Tetraclita ehsani LFSc. ZRC- 184 on shores of Diu B Tetraclita ehsani, external and internal view of scutum and tergum C Tetraclitella karandei ASIZCR 000454 on shores at Diu D shell of T. karandei E Tetraclitella karandei external and internal view of scutum and tergum F Chthamalus barnesi on shores G close up view of C. barnesi LFSc. ZRC- 160 H Internal and external view of scutum and tergum of C. barnesi I Microeuraphia withersi LFSc. ZRC- 161 (BD: 6.01 mm) J internal and external view of scutum and tergum of M. withersi.

Figure 12. Microeuraphia withersi (Pilsbry, 1916). (BD: 6.01 mm), LFSc. ZRC- 161, Light microscopy on mouth parts A maxilla B maxillule C mandible D close up on the inferior angle of mandible E close up on the teeth of mandible F mandibulatory palp G labrum H close up view on the cutting edge of labrum, showing the teeth. Scale bars in µm.