Gyge ovalis
Creators: name: Boyko, Christopher B.
name: Williams, Jason D.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Bopyridae
Gyge
Gyge ovalis

description: Gyge ovalis (Shiino, 1939)
(Fig. 2)
Metabopyrus ovalis Shiino, 1939: 88–91, figs. 7, 8 (Hakata Bay, Kyûsyû, Japan, infesting Upogebia major (De Haan, 1841) (subsequently reidentified as Upogebia issaeffi (Balss, 1913)); Itani et al., 2002: fig. 1 (Japan, infesting U. major).
“ Bopyrus in left gill chamber”— Sakai, 2006: 144 (SMF 30511).
Gyge ovalis — Boyko et al., 2017: 264 (comprehensive synonymy through 2016), fig. 4 (Yilan County, Taiwan, infesting Austinogebia edulis ((Ngoc-Ho & Chan, 1992); Yu et al., 2018: 465–476, fig 1 (Shandong Province, China, infesting Upogebia major (De Haan, 1841); complete mitochondrial genome); Hua et al., 2018: 628 (mitochondrial genome); Selin, 2019: 355–358, fig. 1 (Peter the Great Bay, Sea of Japan, infesting U. major); Marin & Antokhina, 2020: 50 (Russian part of the Sea of Japan, infesting U. major); Sato et al., 2021: 20 (Ariake and Yatsushiro Seas of Kyushu, Japan, infesting U. major); Kim et al., 2023: 2304 (eastern Yellow Sea, South Korea, infesting U. major).
Material Examined: Japan: Female (4.1 mm) with epicaridium larvae and mature male (2.0 mm) (SMF 58106), infesting right branchial chamber of male Upogebia yokoyai Markarov, 1938 (9.3 mm CL), littoral, coarse sand, Uranouchi Inslet, Utsaga, Usa, Kochi, coll. K. Sakai, 20 May 1990 (SMF 30525). Ovigerous female (8.1 mm) and mature male (2.3 mm) (SMF 58105), infesting left branchial chamber of female U. yokoyai (11.9 mm CL, lacking abdomen), Yoshino-gawa, Tokushima City, Tokushinma, coll. K. Sakai, 18 June 1999 (SMF 30518). Ovigerous female (6.9 mm) and mature male (2.2 mm) (SMF 58104), infesting left branchial chamber of female U. yokoyai (11.7 mm CL), Sumiyoshi, Yoshino-gawa, Tokushima City, Tokushima, coll. K. Sakai, 12 June 1992 (SMF 30517). Ovigerous female (9.9 mm) and mature male (3.1 mm) (SMF 58102), infesting left branchial chamber of male U. yokoyai (14.3 mm CL), Jyadani, Tsuda, Tokushima City, Tokushima, coll. K. Sakai, 14 June 1992 (SMF 30511). Mature female (8.2 mm) and mature male (3.2 mm) (SMF 58109), infesting left branchial chamber of male U. yokoyai (13.2 mm CL), Yoshino-Fluss, Tokushima City, Tokushima, coll. K. Sakai, “1938” (SMF 39317). Mature female (6.2 mm) and mature male (2.4 mm) (SMF 58103), infesting left branchial chamber of male U. yokoyai (10.0 mm CL), muddy sand, Yoshino-gawa, Tokushima City, Tokushima, coll. K. Sakai, 11 Jul 1987 (SMF 30516). Mature female (7.7 mm) and mature male (4.0 mm) (SMF 58115), infesting right branchial chamber of male (14.3 mm CL) Austinogebia narutensis (Sakai, 1986), ca. 15 m, otter trawl, off Urado Bay, Kochi City, Kochi, coll. R/ V Toyohata-maru & K. Sakai, 7 Oct 1985 (SMF 30550). Mature female (9.3 mm) and mature male (1.1 mm) (SMF 58101), infesting right branchial chamber of male U. yokoyai (15.6 mm CL); ovigerous female (9.2 mm) (SMF 58101), infesting left branchial chamber of male U. yokoyai (13.2 mm CL), Jyadani, Tsuda, Tokushima City, Tokushima, coll. K. Sakai, 29 Apr 1990 (SMF 30510). Immature female (5.0 mm) and mature male (2.4 mm) (SMF 58113), infesting left branchial chamber of male U. issaeffi (10.3 mm CL), immature female (3.3 mm) and mature male (1.9 mm) (SMF 58113), infesting left branchial chamber of male U. issaeffi (9.3 mm CL), Kokatu-jima, Anan, Tokushima, coll. K. Sakai & S. Maeda, 15 Sep 1993 (SMF 30607). Ovigerous female (8.3 mm) and mature male (3.1 mm) (SMF 58111), infesting right branchial chamber of male U. issaeffi (11.4 mm CL), Kokatu-jima, Ana, Tokushima, coll. K. Sakai & S. Maeda, 16 Sep 1993 (SMF 30605).
Hosts: Austinogebia edulis (Ngoc-Ho & Chan, 1992), A. narutensis (Sakai, 1986), A. wuhsienweni (Yu, 1931), Upogebia carinicauda (Stimpson, 1860), U. issaeffi (Balss, 1913) (possible type host), U. major (De Haan, 1841) (probable type host), and U. yokoyai Makarov, 1938 (see Boyko et al. 2017).
Remarks: An extensive pre-2017 synonymy for this species was provided in Boyko et al. (2017), with discussion of its probable type host. The male from SMF 30525 cited above also had a 5.9 mm specimen of Peregrinamor ohshimai Shôji 1938 on the ventral surface and two additional males from this lot also had these symbiotic clams. Sakai (2006: 145) cited these clams as present but did not mention G. ovalis from this lot. The female host from SMF 30518 has an 18 April 1999 collection data on the specimen label but Sakai (2006: 144) gave the date as 18 June 1999; although the host was cited by Sakai (2006), the parasite was not noted. The male host from SMF 30516 and female host from SMF 30517 were cited by Sakai (2006: 144) but the parasites were not noted. SMF 30550 contains one male and one female mud shrimp (14.0–20.0 mm CL) without parasites; Sakai (2006: 130) cited this material but did not note the symbiont on the one host. SMF 30510 contains 12 male (11.0– 16.9 mm CL) and five female (13.7–16.6 mm CL) mud shrimp, as well as one partial female (carapace only, 15.2 mm CL); Sakai (2006: 144) cited the hosts but did not mention any parasites. One male mud shrimp (10.3 mm CL) from SMF 30607 parasitized by an immature female G. ovalis also bore a 6.9 mm specimen of P. oshimai on the ventral surface while another male (9.3 mm CL) from the same lot bore an immature female G. ovalis and a 6.3 mm clam on the ventral surface; Sakai (2006: 121) noted the presence of the clams on these specimens but made no mention of the bopyrids. SMF 30605 contains 10 male U. issaeffi, one infested by G. ovalis and one infested with Parasacculina shiinoi (Lützen, Itani, Itani, Hong, Rees & Glenner, 2016).
description: Published as part of Boyko, Christopher B. & Williams, Jason D., 2025, New records of crustacean (Isopoda: Bopyridae and Cirripedia: Rhizocephala) and molluscan (Bivalvia: Galeommatoidea) symbionts from gebiid mud shrimps (Crustacea: Decapoda: Gebiidea) with description of a new species of Gyge Cornalia & Panceli, 1861 from Iran, pp. 571-586 in Zootaxa 5621 (5) on pages 574-576, DOI: 10.11646/zootaxa.5621.5.5, http://zenodo.org/record/15263250