Orientomysis koreana ( Ii, 1964 ) Fukuoka & Murano, 2005

Fukuoka, Kouki & Murano, Masaaki, 2005, A revision of East Asian Acanthomysis (Crustacea: Mysida: Mysidae) and redefinition of Orientomysis, with description of a new species, Journal of Natural History 39 (9), pp. 657-708 : 675-677

Orientomysis koreana ( Ii, 1964) comb. nov.

Acanthomysis koreana Ii 1964: 499–501 , Figure 128; Mauchline and Murano 1977: 44

(list); Shen et al. 1989: 208–210, Figure 10 ; Müller 1993: 193 (list); Jo and Ma

1996: 815, Figure 10 ; Wang and Liu 1997: 215; Liu and Wang 2000: 236–238,

Figure 86.

Type locality

Ryubai Island, Haeju Bay, Hwanghaenamdo, western Korea.

Material examined

Syntype: four males (19.2–19.4 mm) and 20 females (14.6–21.2 mm), Ryubai Island , Haeju Bay, Hwanghaenamdo, western Korea, 13 April 1936, Ii’s coll. no. 36 .

Others. Two females (damaged), Yongyoodo, Inchon, western Korea, dip net by diver, 27 April 1986, on loan from S.-G. Jo .

Remarks

Ii (1964) described the first to fourth abdominal somites having a lateral fold which is discontinuous dorsally. On the other hand, Shen et al. (1989) illustrated the fourth abdominal somite with a lateral fold as well as a transverse dorsal fold. In the type specimens, an obscure transverse dorsal fold or groove was recognized on the fourth abdominal somite.

Shen et al. (1989) and Jo and Ma (1996) observed the presence of spines on the dorsal surface near the base of the telson, which were neither described nor illustrated by Ii (1964). Re-examination of the type specimens confirmed that there are two or three pairs of spines.

Orientomysis koreana shows a sexual dimorphism in the size of apical spines of the telson as illustrated by Ii (1964), although he did not describe it. The outer pair of the large apical spines of the telson is only slightly longer than the apicalmost lateral spine in the male, compared with 1.5 times as long in the female.

Orientomysis koreana is allied to O. fujinagai and O. robusta . Morphological differences among these three species are summarized in Table III.

Distribution

This species has been recorded from the western Korea ( Ii 1964; Jo and Ma 1996) and Chinese coasts of the Bohai Sea, the Yellow Sea and the East China Sea ( Shen et al. 1989; Wang and Liu 1997).

This species was collected from depths of 11 to 41 m in Chinese waters ( Wang and Liu 1997).

Figures

Figure 10. Orientomysis sheni (Wang and Liu, 1989) comb. nov. (A, B) Female (9.2 mm); (C–E) male (11.2 mm). (A) Sternal process on thoracic somites, lateral; (B) maxilla, posterior; (C) fourth pleopod, anterior; (D) distal part of fourth pleopod, posterior; (E) telson, dorsal.