Stegoalpheon Chopra, 1923

An, Jianmei, Boyko, Christopher B. & Li, Xinzheng, 2015, A Review Of Bopyrids (Crustacea: Isopoda: Bopyridae) Parasitic On Caridean Shrimps (Crustacea: Decapoda: Caridea) From China, Bulletin of the American Museum of Natural History 2015 (399), pp. 1-85 : 20-23

Stegoalpheon Chopra, 1923

DIAGNOSIS (modified from Markham, 1977): Female: body ovate, wider than long, slightly asymmetrical; head separated from pereon, large frontal lamina. Pereomeres distinct, all except first subequal in length, first shorter, sixth segment not shorter than others, coxal plates on segments 1–4; dorsolateral bosses indistinct, marsupium open. Oostegite 1with prominent posterolateral falcate points extending far beyond sides. Pleomere of 6 segments, distinct dorsally and laterally; segments 1–5 (sometimes 6) with dorsally directed lateral plates and biramous pleopods ventrally located and extending to sides of pleon. Uropods uniramous, similar to pleopods in shape.

Male: Head distinct from pereon, eyes large. Pereomeres well defined. Pleon with all segments fused, pleopods and uropods absent.

TYPE SPECIES: Stegoalpheon kempi Chopra, 1923 , by original designation.

OTHER SPECIES: None.

REMARKS: Chopra (1923) originally de‐ scribed Stegoalpheon kempi as having five pairs of triramous pleopods However, Shiino (1951) and Pillai (1966) convincingly showed that the dorsally directed lobes were lateral plates and that the pleopods were biramous. Markham (1977) stated that the type species has five pairs of uniramous lateral plates and five pairs of uniramous pleopods, but this is incorrect. There is clearly some variability in the number of lateral plates, as Chopra (1923) indicated five pairs, which argrees with the present material, while both Shiino (1951) and Pillai (1966) described specimens with six pairs.

Stegoalpheon kempi Chopra, 1923 Figure 3

Stegoalpheon kempi Chopra, 1923: 462 , 464– 467, text fig. 8, pl. 13, fig. 1–7 [ India, infesting Alpheus cf. lobidens (De Haan, 1849) ]; Shiino, 1951: 26–29, figs. 1–2 [ Japan, infesting Alpheus rapax Fabricius, 1798 ]; Pillai, 1954: 20; Pillai, 1966: 188– 190, figs. 12–20 [ India, infesting Alpheus sp.]; Shiino, 1958: 61 [ Japan, infesting Alpheus rapax Fabricius, 1798 ]; Rao and Ramaprasad, 1964: 588–589, figs. 1–2 [ India, infesting Alpheus malabaricus (Fabricius, 1775) ]; 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 and Boyko, 2010: 150; An, 2011: 134–136, figs. 5-5–5-7 [same material as An et al., 2008].

Stegoalpheon choprai Pillai, 1954: 20 [ India, infesting Alpheus paludicola Kemp, 1915 ]; Rao and Ramaprasad, 1964: 588; Markham, 1977: 109, 111, 120; Kensley, 2001: 226; Williams and Boyko, 2010: 150.

Stegoalpheen [sic] kempi — Rao and Ramaprasad, 1964: 588 (figure caption).

MATERIAL EXAMINED: Infesting Alpheus sp., 1 ♀, 1 ♂ ( CIEAL880701 ), Niuchelun Jiao of Nansha , 116 ° 10′E, 9 ° 36′N, 23 July 1988 ; 1 ♀, 1 ♂ ( CIEAL940901 ), Banyue Jiao of Nansha , 116 ° 16′E, 8 ° 52′N, 29 September 1994 .

DESCRIPTION: Female (CIEAL880701): Length 4.28 mm, maximal width across pereomere 3 4.43 mm, head length 0.88 mm, head width 1.29 mm, almost symmetrical (fig. 3A, B).

Body oval, length 3/4 width. All segments distinct. Head pentagonal, frontal lamina obscure, but anterior margin of the head extended (fig. 3A). Black eyes on lateral corner of anterior margin of head. Antennule of three articles, antennae of four articles, terminally setose (fig. 3C). Maxilliped (fig. 3D) without palp, but tuft of setae indicating palp location. Plectron extend and sharp. Barbula (fig. 3E) with two pairs of falcate lateral projections on each side, one median small tubercle present.

Pereon broadest across third pereomere (fig. 3A). Coxal plates reduced, dorsolateral bosses on first five pereomeres. Tergal projections of pereomeres 2–4 distinct. Brood pouch completely open (fig. 3B). Oostegite 1 with smooth internal ridge, posterolateral point rounded laterally (fig. 3F, G). Pereopods short, with blunt dactyli (fig. 3H). Pleon of six pleomeres, first five pleomeres with small, dorsally directed, tubercular lateral plates. Five pairs of biramous ovate pleopods, those on longer side of body much larger than those on shorter side (fig. 3B). Sixth pleomeres with uniramous uropods, similar in shape to pleopods.

DESCRIPTION: Male (CIEAL880701): Length 2.03 mm, maximal width (across pereomere 4) 0.95 mm, head width 0.52 mm, head length 0.34 mm, pleonal length 0.35 mm (fig. 3I, J). Head pentagonal, separated from first pereomere (fig. 3I). Irregular black eyes near postolateral corner of the head (fig. 3I). Antennule of three articles, antenna of seven articles, much longer than antennule, antennulae and antenna terminally setose (fig. 3K). Pereon much wider than head, segements distinct (fig. 3I), all subequal in width. Pereomeres 6 and 7 with midventral projections (fig. 3J). First four pereopods larger than last three, dactyli of first two larger than others (fig. 3J). Pleon fused into single piece, without any pleopods or uropods (fig. 3J).

HOSTS AND LOCALITIES: Infesting Alpheus cf. lobidens (De Haan, 1849) , Alpheus malabaricus (Fabricius, 1775) , Alpheus paludicola Kemp, 1915 , Alpheus rapax (Fabricius, 1798) , Alpheus sp. ( Alpheidae ), India, Japan, China.

REMARKS: As pointed out by Williams and Boyko (2010), Stegoalpheon choprai was synonymized with S. kempi by Pillai (1966), despite later ( Markham, 1977; Kensley, 2001) citations of the species as valid. The present females conform well with Chopra’ s (1923) holotype although with much smaller dorsally directed lateral plates; however, the present male possesses midventral projections on the last two pereomeres and a wider pereon (allotype male without any midventral projections and a pereon subequal in width compared to the head).

Pseudioninae Codreanu, 1967

DIAGNOSIS: Female: All body segments dis‐ tinct, head usually fused with frontal lamina. Pereon with coxal plates, dorsolateral bosses, and tergal projections. Pleopods usually biramous, uropods present.

Male: Head separated from first pereomere, or fused on posterior edge. All pereomeres distinct, often with midventral tubercles. Pleon with one (fused) or six distinct pleomeres, usually with tubercular or flaplike pleopods on first five pleomeres. Uropods sometimes present.

REMARKS: Pseudioninae is largest and most heterogeneous subfamily in Bopyridae , in‐ cludes 48 genera and 236 species, and may not be monophyletic ( Williams and Boyko, 2012). Some species possess putatively primitive characters, such as males having lateral plates on the pleon and well-developed pleopods. All species are branchial parasites and most species infest anomurans, axiideans, and gebiideans, with relatively few being found on carideans and brachyurans.

Figures

Fig. 3. Stegoalpheon kempi Chopra, 1923, female (CIEAL880701) (A–H): A. Dorsal view. B. Ventral view. C. Left antenna and antennule. D. Right maxilliped, external view. E. Barbula. F. Right oostegite 1, external view. G. Right oostegite 1, internal view. H. Right pereopod 2. Male (CIEAL880701) (I–K): I. Dorsal view. J. Ventral view. K. Antenna and antennule. Scale: 1 mm (A, B, D–G,); 0.5 mm (H–J), 0.25 mm (C, K).