Pinnotheres obscurus Stimpson, 1858

Wong, Kingsley J. H., Ng, Peter K. L., Shih, Hsi-Te & Chan, Benny K. K., 2024, Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population., Zoological Studies 63 (38), pp. 141-149 : 123

Pinnotheres obscurus Stimpson, 1858

Pinnotheres obscurus Stimpson, 1858b: 108 ; Stimpson 1907: 141; Gee 1926: 163 [list]; Shen 1940a: 230 [no new specimens]; Pregenzer and Morton 1990: 653.

Taxonomy: Stimpson (1907), Schmitt et al. (1973),

Pregenzer and Morton (1990). Type: Probably lost. Type locality: Hong Kong. Distribution: South China: Hong Kong only (see

Remarks below). Habitat: Symbiont or parasite of bivalves. Remarks: The present species was originally described based on a single female holotype, collected “in portu “ Hong Kong ”, now believed lost, and the species remains poorly known ( Stimpson 1907; Schmitt et al. 1973). The original descriptions are unfortunately too schematic to offer any precise identification. This name, however, was applied to numerous specimens from Hong Kong by Pregenzer and Morton (1990), who argued that P. cyclinus Shen, 1932 and P. excussus Dai, Feng, Song & Chen, 1980 are synonymous with P. obscurus Stimpson, 1858 , the differences observed only representing intraspecific variation. In contrast, Dai et al. (1980) and Dai and Yang (1991) had treated both P. cyclinus and P. excussus as distinct, valid species, symbiotic in different host bivalve genera, and both were referred to a separate genus, Arcotheres Manning, 1993 ( Ng et al. 2017b; Ng and Ngo 2022). In any case, as the evidence for the possible synonymy of P. obscurus with either P. cyclinus or P. excussus is still weak, we opt to keep these taxa as distinct.