Pilumnus vespertilio (Fabricius, 1793)

Pilumnus vespertilio (Fabricius, 1793) View in CoL

Pilumnus verspertilio — Hill et al. 1978: 92; Morton and Morton 1983: 186.

Taxonomy: Sakai (1939), Takeda and Miyake (1968).

Type: Syntype in ZMK ( Zimsen 1964), now probably in NHMD.

Type locality: India, locality unspecified.

Distribution: Western Indian Ocean to Central Pacific: from South Africa, Red Sea, Persian/Arabian Gulf, India, Southeast and East Asia to Japan, Palau, Australia, New Caledonia, to Hawaii ( Takeda and Miyake 1968).

Habitat: Intertidal and shallow subtidal; fringing coral reefs.

Ser amoyensis Gordon, 1930 View in CoL #

Ser fukiensis View in CoL — Wong et al. 2021: 37, fig. 59, pl. 12A.

Ser amoyensis View in CoL — Ng and Wong 2024: 12, figs. 1–5, 7K, L.

Taxonomy: Gordon (1930: as Litocheira View in CoL ), Rathbun

( 1931: as S. fukiensis ), Ng and Wong (2024). Type locality: Xiamen (as Amoy), China. Type: Holotype ò NHM 1930.11.14.34. Distribution: South China: Guangdong ( Hong

Kong) to Fujian.

Habitat: Subtidal; on sandy-muddy substrates of estuarine seas.

Remarks: Understanding of Ser fukiensis Rathbun, 1931 has remained obscure for many decades, and the name recently shown to be a junior synonym of Litocheira amoyensis , likewise poorly known, described merely months prior in 1930 ( Ng and Wong 2024). See Remarks under S. sasekumari below.

Ser sasekumari (Serène, 1971) #

Heteropilumnus sasekumari — Bravo et al. 2021: tab. 2.

Ser sasekumari — Ng and Wong 2024: figs. 6, 7A–I, M–O.

Taxonomy: Ng (1985: as Rhizopa ), Ng and Davie (1991: as Heteropilumnus ), Ng and Wong (2024).

Type locality: Port Klang (as Port Swettenham), Malaysia.

Type: Holotype ñ ZRC 1969.12 View Materials .2.7 ( Ng and Davie 1991).

Distribution: Eastern Indian Ocean to West Pacific: from northeastern Australia, Phuket ( Thailand), western Peninsular Malaysia, Singapore and South China, to Papua, Indonesia (Serène 1971; Ng and Davie 1991; Davie 2002; BY Lee and NK Ng 2012; Widyastuti and Rahayu 2022).

Remarks: This species was originally described under Rhizopa Stimpson, 1858 by Serène (1971) with doubt, and this generic placement was challenged by Guinot (1979), with Ng and Davie (1991) tentatively placing it under Heteropilumnus De Man, 1895 . Heteropilumnus has long been considered heterogenous ( Ng and Tan 1988; Ng and Davie 1991; Ng et al. 2018; Maenosono 2019), and the identity of the allied Ser Rathbun, 1931 was poorly understood ( Ng 1987). The second author has since examined the type of Ser fukiensis Rathbun, 1931 , the type and previously the only species in Ser , and we have obtained fresh specimens from Hong Kong. We also have examined specimens of Heteropilumnus stormi De Man, 1895 , the type species of Heteropilumnus De Man, 1895 , which differs from typical members of this genus in being covered by a short dense felt-like pubescence, without any long setae lining the margins of the carapace or appendages. Comparing Ser amoyensis with our specimens of H. sasekumari from Hong Kong and Southeast Asia (cf. Ng and Davie 1991; BY Lee and NK Ng 2012; Widyastuti and Rahayu 2022; Ng and Wong 2024), we are certain that they are congeneric. As such, Rhizopa sasekumari Serène, 1971 , was referred to Ser Rathbun, 1931 . The taxonomy of these and allied species has been elaborated at length recently by Ng and Wong (2024), and in further work in progress.