Plesionika Bate, 1888

Li, Xinzheng & Komai, Tomoyuki, 2003, Pandaloid Shrimps From The Northern South China Sea, With Description Of A New Species Of Plesionika (Crustacea: Decapoda: Caridea), Raffles Bulletin of Zoology 51 (2), pp. 257-275 : 260

Genus Plesionika Bate, 1888

Remarks. – The taxonomy of Plesionika needs more extensive study in spite of recent revisionary studies ( Chace, 1985; Crosnier, 1986; Chan & Crosnier, 1991, 1997; Chan & Yu, 1991, 2000; Chan, in press). We follow Chace (1985) in treating the genus Parapandalus Borradaile, 1899 as a synonym of Plesionika . Liu & Zhong (1994) listed the following 15 species from Chinese waters: Plesionika alcocki ( Anderson, 1896) ; P. binoculus ( Bate, 1888) ; P. bifurca Alcock & Anderson, 1894 ; P. crosnieri Chan & Yu, 1991 ; P. dentirostris Tung, Wang & Li, 1988 ; P. edwardsii ( Brandt, 1851) ; P. ensis (A. Milne Edwards, 1881) ; P. indica De Man, 1917 ; P. izumiae Omori, 1971 ; P. martia (A. Milne Edwards, 1883) ; P. ortmanni Doflein, 1902 ; P. semilaevis Bate, 1888 ; P. sindoi ( Rathbun, 1906) ; P. unidens Bate, 1888 ; and P. yui Chan & Crosnier, 1991 .

The present study confirms the occurrence of the 12 previously known species in the northern part of the South China Sea: P. bifurca , P. grandis , P. indica , P. izumiae , P. kensleyi , P. narval , P. phlippinensis , P. puimila , P. ortmanni , P. semilaevis , P. sindoi , and P. spinensis .

Chace (1985) revealed that all of the material assigned to P. binoculus since the original description by Bate (1888) ( De Man, 1920; Boone, 1935; Hayashi & Koike, 1976) belonged to a distinct species, P. lophotes Chace, 1985 . The true P. binoculus is so far represented with certainty only by the syntypes from the Arafura Sea. Although it is difficult to satisfactorily determine the specific identity of P. binoculus from Chinese waters without reexamination of the types, it is probable that the Chinese material represents this or other closely allied species (cf. Chan, in press).

Tung et al. (1988) described a new species Plesionika dentirostris from the East China Sea. Subsequently Chan & Yu (1991) described a new species P. crosnieri from Taiwan. Chan & Yu (1991) compared the new species with P. edwardsii , but omitted to mention P. dentirostris despite the close similarity. Future study may eventually reveal that P. crosnieri and P. dentirostris are conspecific. The problem, however, is far more complicate since P. costelloi ( Yaldwyn, 1971) and P. chwitchii Burukovsky, 1978 also seem closely related to both P. crosnieri and P. dentirostris .

There are still many uncertainties concerning the relationship between P. ensis and P. reflexa Chace, 1985 (cf. Chan & Crosnier, 1997). Chace (1985) referred the material from the Philippines and Indonesia to P. reflexa and Hayashi (1986) reported this species from Japan. While the distribution of P. ensis in the northwestern Pacific remains not fully established. Therefore, the Chinese records of P. ensis may actually represent P. reflexa .

The Plesionika martia species group (cf. Chan & Crosnier, 1997) is generally considered to be a difficult species complex (e.g. Crosnier & Forest, 1973; Chace, 1985; Hanamura & Takeda, 1987; Kensley et al., 1987; Chan & Crosnier, 1997). It is possible that the Chinese records of P. martia contain more than two species.

Liu & Zhong (1994) listed Parapandalus zurstrasseni Balss, 1914 from the South China Sea. The name is generally considered to be a junior synonym of Stylopandalus richardi ( Coutiere, 1905) (cf. Crosnier & Forest, 1973; Chace, 1985).