Stegias clibanarii Richardson, 1904

Romero-Rodriguez, Jesús & Álvarez, Fernando, 2023, Parasitic bopyrid isopods of hermit crabs (Anomura, Paguridae) from the Atlantic coast of Mexico, with notes on their reproduction and distribution, European Journal of Taxonomy 861, pp. 132-167 : 142-143

Stegias clibanarii Richardson, 1904

Figs 1 , 2C , 5 , Table 1

Stegias clibanarii Richardson, 1904: 59–60 , fig. 34.

Stegias clibanarii – Richardson 1905: 536–537, fig. 580. — Verril 1908: 448, fig. 64. — Nierstrasz & Brender à Brandis 1923: 107; 1931: 200. — Menzies & Glynn 1968: 13, 18–19, 83 fig. 3. — Schultz 1969: 322, fig. 514. — Markham 1972: 64–65; 1975a: 225–230, figs 1–2; 1975b: 260, 263; 1978: 102 (in key), 103–104, 111–112, 116, fig. 10, table 1; 1979: 523 (in key), 526–527; 1988: 3, 46–48, fig. 18, table 1; 2003: 72. — McDermott 1974: 2; 2002: 34–40, figs 1–2, table 1. — Ross 1983: 167. — Schultz 1986: 371, 372, pl. 123. — Kensley 1994: 320 (in table 1). — Campos 2003: 79–80, 86. — Romero-Rodríguez & Román-Contreras 2008: 1207; 2013: 646 (in table 3). — McDermott et al. 2010: 12 (in table 1), 27. — Trilles & Hipeau-Jacquotte 2012: 288. — Cericola & Williams 2015: 238 (in table I). — Romero-Rodríguez & Álvarez 2020: 2226 (in table 2).

non Stegias clibanarii – Pearse 1932: 4–5, figs 22–26. — Schultz 1969: 323, fig. 515.

Material examined

MEXICO • 1 ovigerous ♀ (3.80 mm TL), 1 ♂ (1.64 mm TL); Veracruz, Los Tuxtlas, Montepío ; 18º38′34″ N, 95º05′50″ W; Jul. 2002; A. Argüelles and M. Maldonado leg.; host ♀ of Clibanarius tricolor (Gibbes, 1850) (3.60 mm SL); A. Argüelles det. host; CNCR-36487 .

Distribution

Stegias clibanarii has been recorded exclusively in the Caribbean region: Bermuda ( Richardson 1904), San Juan, Puerto Rico (Menzies & Gynn 1968) and Magdalena, Colombia ( Markham 1988); with the new records its geographic range extends to the southwestern Gulf of Mexico ( Fig. 1 ), likewise also represents the first evidence of its occurrence in Mexican coasts. The only known host for this bopyrid species so far is C. tricolor .

Remarks

The material examined ( Figs 2C , 5A, G ) agree in most details with the descriptions given by Richardson (1904) and Markham (1975a) for Stegias clibanarii , only differing in the following aspects: female with small eyes on the anterolateral margins of head ( Fig. 5A ), the barbula’s left projection more pointed than that on the opposite side ( Fig. 5B ), first pair of oostegites with a curved projection in the proximal end of the inner margin ( Fig. 5 C-D) and all five pairs of pleopods biramous ( Fig. 5E ). The maxilliped, not previously described, with anterior segment square in shape and much larger than posterior one, without palp but anterior and distal margin folded, converging in superior lateral margin giving it pointed appearance; posterior segment rectangular in shape ( Fig. 5F ). Male with the fusion of head and first pereomere not as conspicuous ( Fig. 5G ) as that illustrated by Markham (1975a).

Reproduction

The size of the female examined (3.80 mm TL) was similar to the average size for ovigerous females (3.55 ± 0.44 mm) previously reported ( McDermott 2002) but the number of embryos counted in our female ( Table 1 ) was almost three times as high as the maximum fecundity reported (667 embryos) for S. clibanarii by McDermott (2002). The average embryos’ length and width recorded ( Table 1 ) were similar to those reported by McDermott (2002) for embryos recently deposited in the marsupium

(0.157 ± 0.008 and 0.133 ± 0.016 mm, respectively) but their average volume was smaller than the 0.0015 mm 3 calculated by Romero-Rodríguez & Álvarez (2020).

The size of the male examined (1.64 mm TL) is in the range of 0.78 to 1.71 mm TL reported by McDermott (2002), although Markham (1975a) noted that males of this species can reach 2.6 mm TL.

The prevalence calculated for S. clibanarii was of 25%; however, the sample was only of four hermit crabs.

Figures

Fig. 1. Distribution along the American continent of five bopyrid species that parasite hermit crabs recorded in the Mexican Atlantic. A. Detail of the Atlantic coast of Mexico.

Fig. 2. Dorsal view of ovigerous females of bopyrid isopods that parasites hermit crabs in Atlantic Mexican coasts.A. Anathelges hyptius (Thompson, 1902) (CNCR-36525-C). B. Pseudostegias atlantica Lemos de Castro, 1965 (CNCR-36483). C. Stegias clibanarii Richardson, 1904, stained with methylene blue (CNCR-36487). D. Asymmetrione desultor Markham, 1975 (CNCR-36488). E. Asymmetrione tuxtlaensis sp. nov., with male ventrally attached to pleon (CNCR-36495). F. Bopyrissa wolffi Markham, 1978 (CNCR-36502-A). Scale bars: A–E = 1.0 mm; F = 0.5 mm.

Fig. 5. Stegias clibanarii Richardson, 1904 (CNCR-36487). A. Ovigerous ♀, dorsal view. B. Barbula. C. First oostegite, external view. D. Same, internal view. E. Pleon, ventral view. F. Maxilliped. G. ♂, dorsal view. Numbers indicate pairs of pleopods.Abbreviation: lp = lateral plate. Scale bars: A = 1.0 mm; B–G = 0.5 mm.