Heterocepon marginatum Shiino 1936
Creators: name: Boyko, Christopher B.
name: Williams, Jason D.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Bopyridae
Heterocepon
Heterocepon marginatum

description: Heterocepon marginatum Shiino, 1936
(Figs 1; 2)
Heterocepon marginatum Shiino, 1936a: 161, 165-168, fig. 2 [ex Pinnotheres parvulus Stimpson, 1858, Japan]; 1936c: 185 [ex P. parvulus, Japan]; 1972: 9 [list]. — Morita 1940: 76-77 [ex Pinnotheres sp., Japan]; 1949: 13-14, figs A-E [ex Nepinnotheres cardii (Bürger, 1895), Japan; description of cryptoniscus larva]; 1951: 48 [ex N. cardii, Japan]; 1952: 54-59, figs 1-3; 1953a: 10, 13 [ex N. cardii, Japan; 1953b: 14-20, figs 1-4 [ex N. cardii, Japan; description of epicaridium larva, bopyridium, juvenile male and female]; 1955: 53-59 [ex N. cardii, Japan; fig. 1-5]. — Danforth 1963: 8 [list]. — Wells & Wells 1966: 57 [mention]. — Janssen & Brandt 1994: 12-17, 24, table 1, figs 3-9 [ex Arcotheres palaensis (Bürger, 1895), Philippines]. — Saito et al. 2000: 42 [list]. — Boyko & Williams 2001: 656 [mention]. — Miura et al. 2014: 31, 35, 36 [mention]. — Ozeki et al. 2014: 49 [mention]. — Williams et al. 2023: 532 [list], 539 [mention].
“bopyrid isopod” – Janssen 1986: 15, 23, fig. 5 [ex A. palaensis, Philippines].
“hyperparasite” – Janssen 1986: 18 [ex A. palaensis, Philippines].
“bopyrid”– Ahyong & Ng 2007: 200 [ex A. palaensis, paralectotype female (SMF-ZMG948b), Palau; photographs examined herein]. — Ng & Ahyong 2022: 145 [ex ZRC 1987.537-539; specimen examined herein], 148 [ex ZRC 1993.120-122; host examined herein], 195 [ex ZRC 2013.1416; specimens examined herein].
“unidentified bopyrids” [of Arcotheres palaensis (in part) and Arcotheres rayi] – Williams et al. 2023: 533 [list].
MATERIAL EXAMINED. — Peninsular Malaysia or Singapore • 1 ovigerous ♀ (4.5 mm TL), 1 mature ♂ (3.0 mm TL), from left branchial chamber of female Arcotheres palaensis (Bürger, 1895) (5.7 mm CL, 9.6 mm CW; ZRC 1987.537-539), ex Tegillarca granosa (Linnaeus, 1758) (Arcidae); from markets; 20.XI.1986; P. K. L. Ng, leg.; ZRC 2023.0257.
Malaysia • 1 mature ♀ (3.5 mm), 1 mature ♂ (1.8 mm), from right branchial chamber of female Arcotheres rayi Ahyong & Ng, 2007 (5.0 mm CL, 7.0 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0262 • 1 mature ♀ (3.2 mm), mature ♂ (2.8 mm), from left branchial chamber of female A. rayi (4.9 mm CL, 8.0 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0263 • 1 ovigerous ♀ (3.4 mm), 1 mature ♂ (2.6 mm), from right branchial chamber of female A. rayi (5.0 mm CL, 7.5 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0264 • 1 ovigerous ♀ (3.6 mm), 1 mature ♂ (3.2 mm), from right branchial chamber of female A. rayi (4.9 mm CL, 8.0 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0265 • 1 immature ♀ (2.5 mm), from left branchial chamber of female A. rayi (3.8 mm CL, 5.7 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0266 • 1 ovigerous ♀ (4.0 mm), 1 mature ♂ (2.9 mm), from right branchial chamber of female A. rayi (5.0 mm CL, 8.5 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae Rafinesque, 1815); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0267 • 1 ovigerous ♀ (4.2 mm), 1 mature ♂ (3.5 mm), from left branchial chamber of female A. rayi (6.0 mm CL, 10.0 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0269 • 1 ovigerous ♀ (3.6 mm), 1 mature ♂ (2.8 mm), from left branchial chamber of female A. rayi (4.7 mm CL, 8.0 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0270 • 1 ovigerous ♀ (3.6 mm), 1 mature ♂ (2.8 mm), from left branchial chamber of female A. rayi (4.6 mm CL, 8.0 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0271 • 1 ovigerous ♀ (3.0 mm), 1 mature ♂ (2.8 mm), 1 immature ♂ (1.0 mm), from right branchial chamber of female A. rayi (4.7 mm CL, 7.3 mm CW; ZRC 2013.1416), ex Paphia sp. (Veneridae); Pahang, Bentong Market; 10.V.2010; M. Low leg.; ZRC 2023.0272.
“ Singapore? ” • 1 ovigerous ♀ A. palaensis (7.1 mm CL, 9.0 mm CW; with swollen empty right branchial chamber), ex T. granosa; market; 8.XII.1987; P. K. L. Ng leg.; ZRC 1993.120-122.
REMARKS
This is the first record of the species from Malaysia and likely Singapore based on the host branchial chamber swelling; however, because some specimens were obtained from markets where field sites were not noted, the country of origin remains unclear for some of the museum lots. The female (Figs 1A, D; 2) and male (Fig. 1B) specimens match the original description. An additional parasitized ovigerous female Arcotheres palaensis (ZRC 1993.120-122) was examined but the swollen branchial chamber was empty. In light of the identity of the host, the bopyrid was probably H. marginatum.
In situ photographs of a female specimen in a host Arcotheres palaensis (SMF-ZMG 948b) (Fig. 1C) and the extracted female (Fig. 1 D) were examined. The female bopyrid identity was confirmed, but no male was present.
description: Published as part of Boyko, Christopher B. & Williams, Jason D., 2024, New records of bopyrid parasites (Crustacea, Isopoda, Epicaridea) of pea crabs (Crustacea, Decapoda, Pinnotheridae) with descriptions of two new species of Rhopalione Pérez, 1921 and a review of the genus, pp. 149-175 in Zoosystema 46 (7) on pages 153-154, DOI: 10.5252/zoosystema2024v46a7, http://zenodo.org/record/10863451