Stegoalpheon kempi Chopra, 1923

An, Jianmei, Zhang, Pengchi & Paulay, Gustav, 2017, A new genus and two new species of Argeiinae (Crustacea: Isopoda: Bopyridae) from the Indo-west Pacific, Journal of Natural History 51 (7 - 8), pp. 405-420 : 416-417

Stegoalpheon kempi Chopra, 1923

( Figures 5 and 6 )

Stegoalpheon kempi Chopra, 1923: 462 , 464–467, text fig. 8, pl. 13, fig. 1–7 [ India, infesting Alpheus cf. lobidens ]; Shiino, 1951: 26–29, figs 1–2 [ Japan, infesting Alpheus rapax ]; Pillai, 1954: 20; Pillai, 1966: 188–190, figs 12–20 [ India, infesting Alpheus sp. ]; Shiino, 1958: 61 [ Japan, infesting Alpheus rapax ]; Rao & Ramaprasad, 1964: 588–589, figs 1–2 [ India, infesting Alpheus malabaricus ]; Shiino, 1972: 8; Kannupandi, 1976: 87–93, figs 1–3; Markham, 1977: 109–111, 119–120; Adkison et al., 1982: 337; Kensley, 2001: 226; An, 2006: 65–65, fig. 27; An et al., 2008: 225–226, fig. 2 [ China, infesting Alpheus sp. ]; Liu, 2008: 693; Williams & Boyko, 2010: 150; An, 2011: 134–136, figs 5-5-5-7 [same material as An et al., 2008]; An et al., 2015: 20–22, fig. 3.

Stegoalpheon choprai Pillai, 1954: 20 [ India, infesting Alpheus paludicola ]; Rao & Ramaprasand, 1964: 588; Markham, 1977: 109, 111, 120; Kensley, 2001: 226; Williams & Boyko, 2010: 150.

Stegoalpheen [sic] kempi – Rao & Ramaprasand, 1964: 588 (figure caption).

Material examined

UF Arthropoda 42225, 1♀, 1♂, infesting Alpheus cf . perplexus. ( UF Arthropoda 27567) . Australia, Western Australia, Ningaloo reef, Norwegian Bommies , 5–6 m, 22.6206° S, 113.6424° E; 27 May, 2010, coll ., Slava Ivanenko , Arthur Anker .

Remarks

Chopra (1923) erected the genus Stegoalpheon for S. kempi , based on females with five pairs of triramous pleopods: with two ventral rami and a third ramus arising dorsally in the form of a vertical ridge. Shiino (1951, 1958) recorded S. kempi from Japan, and suggested that the triramous pleopods described by Chopra (1923) should be reinterpreted as biramous, with the dorsal ramus representing a lateral plate. Pillai (1954) provided a very brief description of S. choprai and later ( Pillai 1966) relegated it into synonymy with S. kempi .

The present specimens extend the range of this species from India, the Andaman Islands and Japan, to Western Australia. The Australian specimens conform well with Chopra’ s (1923) description ( Figure 5 (a,b)) with a similar first oostegite ( Figure 5 (e,f)), and in the overall morphology of the male ( Figure 6 ). However, they show some minor differences: (1) barbula ( Figure 5 (c)) with two pairs of small projections on each side, versus specimens of Shiino (1951) with four pairs, and of Chopra (1923) with two pairs of triangular projections; (2) maxilliped ( Figure 5 (d)) with a short palp having a ciliated margin, versus specimens of Chopra (1923) and Shiino (1951) with maxilliped lacking a palp. (3) endopodites ( Figure 5 (i) much smaller than respective exopodites, whereas described specimens ( Chopra 1923; Shiino 1951; Pillai 1966) had subequal exopodites and endopodites. These differences are probably the result of different degrees of maturity of the studied specimens.

Figures

Figure 5. Stegoalpheon kempi Chopra, 1923. Female: (a) Dorsal view. (b) Ventral view. (c) Right side of barbula. (d) Left maxilliped, external view. (e) Right oostegite 1, external view. (f) Right oostegite 1, internal view. (g) Left pereopod 1. (h) Left pereopod 7. (i) Ventral view of pleon (endopodites shaded). Scale = 1 mm (a, b), 0.42 mm (c, e, f, i), 0.26 mm (d), 0.14 mm (g, h).

Figure 6. Stegoalpheon kempi Chopra, 1923. Male: (a) Dorsal view. (b) Ventral view. (c) Left antenna and antennule. (d) Right pereopod 1. (e) Right pereopod 2. (f) Right pereopod 3. (g) Right pereopod 7. Scale = 1 mm (a, b), 0.55 mm (c, d, e, f, g).