Orientomysis tenuicauda ( Murano, 1984 ) 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 : 695-697

Orientomysis tenuicauda ( Murano, 1984) comb. nov.

Acanthomysis sp. Ikematsu 1963: 87 , Plate 5, Figure 2 .

Acanthomysis tenuicauda Murano 1984: 112–116 , Figures 3b , 4 , 5 ; Müller 1993: 199 (list); Jo and Ma 1996: 818–820, Figure 13 .

Type locality

31 ° 50.59N, 124 ° 02.09E to 31 ° 49.09N, 124 ° 03.09E, the East China Sea .

Material examined

Holotype: female (10.3 mm), the East China Sea (31 ° 50.59N, 124 ° 02.09E to 31 ° 49.09N, 124 ° 03.09E), 42 m, bottom net, 20–21 May 1968, NSMT-Cr 8609 . Allotype: male (11.6 mm), same data as holotype, NSMT-Cr 8610. Paratype: 10 males (9.8–11.4mm) and 10 females (9.7–11.9mm), same data as holotype, NSMT-Cr 8611 .

Others. Five males (8.3–11.1 mm) and five females (10.4–12.4 mm), collection data same as holotype, NSMT-Cr 15600. Three females (10.8–10.9 mm), Boryong, Chungchongnamdo, western Korea, dip net by diver, 1 April 1992, on loan from S.-G. Jo. Abundant males (7.2–8.8 mm) and females (6.7–8.4 mm), Hiuchi-nada, Seto Inland Sea, western Japan, 14–24 m, sledge, 14 September 1995, on loan from Y. Hanamura. Eleven males (8.7–12.2 mm) and 10 females (7.9–11.4 mm), 34 ° 29.809N, 137 ° 01.709E, Enshu-nada, central Japan, 26.8 m, bottom net, 13 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15601. Nine males (11.2–12.7 mm) and 11 females (10.8–13.6 mm), 34 ° 23.409N, 137 ° 02.909E, Enshu-nada, central Japan, 55.7 m, bottom net, 13 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15602. Eighteen males (7.3–11.9 mm) and 21 females (8.1–12.9 mm), 34 ° 23.409N, 137 ° 02.909E, Enshu-nada, central Japan, 55.7 m, bottom net, 14 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15603. Eleven males (9.4– 12.4 mm) and 10 females (8.5–11.4 mm), 34 ° 36.609N, 137 ° 57.499E, Ise Bay, central Japan, 42 m, bottom net, 14 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15604. Eleven males (7.6–11.3 mm) and eight females (7.8–12.2 mm), 34 ° 41.009N, 136 ° 43.209E, Ise Bay, central Japan, 35.0– 36.1 m, bottom net, 15 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15605. Eight males (7.8–10.3 mm) and 10 females (8.3–11.2 mm), 34 ° 41.009N, 137 ° 04.009E, Mikawa Bay , central Japan, 18.6 m, bottom net, 15 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15606. Two males (8.3 mm and damaged) and five females (6.5–7.9 mm), 34 ° 49.979N, 136 ° 47.239E, Ise Bay , central Japan, 23.2 m, bottom net, 16 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15607. Two males (8.2 and 8.5 mm) and one female (8.4 mm), 34 ° 55.109N, 136 ° 46.609E, Ise Bay , central Japan, 24.1 m, bottom net, 16 June 1996, TR/ V Seiyo-Maru cruise, NSMT-Cr 15608. Three males (9.4–11.1 mm), 10 immature males (4.4–6.1 mm), three females (9.1–10.0 mm), eight immature females (4.3–6.1 mm) and 12 juveniles (3.0– 4.8 mm), 34 ° 37.099N, 137 ° 30.069E, Enshu-nada, central Japan, 39 m, bottom net, 17 July 1996, R / V Tansei- Maru cruise, NSMT-Cr 15609. Two males (6.2 and 6.6 mm), 33 ° 51.589N, 134 ° 58.219E, Kii Channel, central Japan, 59 m, bottom net, 15 June 1997, TR/ V Seiyo-Maru cruise, NSMT-Cr 15610. Seven males (6.6–8.7 mm), 11 immature males (4.5–5.6 mm), 17 females (6.8–9.4 mm), eight immature females (4.7–5.8 mm) and 36 juveniles (3.3– 5.0 mm), 34 ° 02.169N, 134 ° 57.949E, Kii Channel, central Japan, 73 m, bottom net, 15 June 1997, TR/ V Seiyo-Maru cruise, NSMT-Cr 15611. Two males (6.1 and 6.1 mm), four immature males (5.0– 5.3 mm), one female (9.3 mm), three immature females (5.2, 5.7 mm and damaged) and 14 juveniles (3.5–5.2 mm), 34 ° 07.229N, 134 ° 58.009E, Kii Channel, central Japan, 74 m, bottom net, 15 June 1997, TR/ V Seiyo-Maru cruise, NSMT-Cr 15612. Three immature females (4.2–4.4 mm) and two juveniles (3.6 and 3.7 mm), 34 ° 11.799N, 134 ° 57.959E, Kii Channel, central Japan, 59 m, bottom net, 15 June 1997, TR/ V Seiyo-Maru cruise, NSMT-Cr 15613. Nine males (8.2–11.2 mm) and seven females (8.5–10.4 mm), 34 ° 24.709N, 135 ° 04.839E, Osaka Bay, central Japan, 40 m, bottom net, 16 June 1997, TR/ V Seiyo-Maru cruise, NSMT-Cr 15614. Eight males (7.1– 9.3 mm), two immature males (6.0 mm and damaged), four females (7.4–8.8 mm), six immature females (4.8–6.8 mm) and three juveniles (2.7–3.7 mm), 34 ° 32.039N, 135 ° 13.989E, Osaka Bay, central Japan, 21 m, bottom net, 16 June 1997, TR/ V Seiyo- Maru cruise, NSMT-Cr 15615. Ten immature males (4.4–6.2 mm), two females (6.7 and 6.2 mm), three immature females (5.2–5.8 mm) and 10 juveniles (3.7–5.0 mm), 34 ° 38.889N, 135 ° 21.889E, Osaka Bay , central Japan, 14 m, bottom net, 16 June 1997, TR/ V Seiyo-Maru cruise, NSMT-Cr 15616. Three males (9.2–9.3 mm) and three females (9.6–9.7 mm), Suruga Bay off Yui , Shizuoka, central Japan, date unknown, NSMT-Cr 15617 .

Remarks

Orientomysis tenuicauda is closely related to O. sheni in the shape of the telson, but differs from the latter species in the following points: (1) the inner margin of the second segment of the mandibular palp is armed with setae and several peculiar protuberances in O. tenuicauda , whereas it is armed only with setae in O. sheni ; (2) the abdomen is furnished with a transverse row of spinules on only the sixth somite in O. tenuicauda compared with spinules on the fourth and fifth somites in O. sheni ; (3) in O. tenuicauda the two terminal long setae on the exopod of the fourth male pleopod are unequal in length, longer seta 1.3 times as long as shorter one, whereas in O. sheni these are subequal; and (4) in O. tenuicauda the outer pair of apical spines of the telson is as long as or a little shorter than the larger lateral spines, while in O. sheni it is markedly longer than the larger lateral spines.

Distribution

This species has been collected from embayments and shallow water regions around Japan and Korea: the Ariake Sea (Ikematsu 1963), Suruga Bay, Ise Bay, Mikawa Bay, Enshunada, Osaka Bay, Kii Channel, the Seto Inland Sea (present study), the East China Sea ( Murano 1984), and Pyonsan and Boryong, western Korea ( Jo and Ma 1996).

This species was collected from a depth of 42 m in the East China Sea ( Murano 1984) and from depths of 14–74 m in the Japanese waters (present study).

Figures

Figure 2. Orientomysis hwanhaiensis (Ii, 1964) comb. nov. (A, B) Telson, dorsal; (C–F) distal end of telson, dorsal. (A) Male (12.2 mm), syntype; (B) female (13.6 mm), syntype; (C) male (9.8 mm), East China Sea, NSMT-Cr 15559; (D) male (7.5 mm), East China Sea, NSMT-Cr 15559; (E) female (10.7 mm), East China Sea, NSMT- Cr 15559; (F) female (10.6 mm), East China Sea, NSMT-Cr 15559.

Figure 3. Orientomysis japonica Marukawa, 1928. (A) First to sixth abdominal somites, lateral; (B–E) telson, dorsal. (A) Male (11.0 mm), Tateyama Bay, Pacific, NSMT-Cr 15562; (B) male (11.0 mm), Tateyama Bay, NSMT-Cr 15562; (C) male (14.2 mm), Uchiura Bay, Pacific, NSMT-Cr 15560; (D) female (17.0 mm), Kashima, Pacific, NSMT-Cr 15570; (E) male (10.6 mm), Japan Sea side of Aomori, NSMT-Cr 15571.

Figure 4. Orientomysis japonica Marukawa, 1928. Distal end of telson, dorsal. (A) Female (13.9 mm), Kashima, Pacific, NSMT-Cr 15569; (B) male (10.2 mm), Uchiura Bay, Pacific, NSMT-Cr 15560; (C) female (broken), Uchiura Bay, Pacific, NSMT-Cr 15560; (D) male (11.8 mm), type of Acanthomysis nakazatoi, Iwai, Pacific; (E) male (11.7 mm), type of A. nakazatoi, Iwai, Pacific; (F) female (10.2 mm), Tateyama Bay, Pacific, NSMT-Cr 15562; (G) female (11.5 mm), Japan Sea side of Aomori, NSMT-Cr 15571; (H) female (11.4 mm), Japan Sea side of Aomori, NSMT-Cr 15571; (I) female (13.0 mm), Tottori, Japan Sea, NSMT-Cr 15572; (J) female (15.8 mm), Tottori, Japan Sea, NSMT-Cr 15572.

Figure 5. Orientomysis meridionalis (Liu and Wang 1983) comb. nov. Male (5.2 mm). (A) Anterior part of body, dorsal; (B) maxilla, posterior; (C) fourth pleopod, posterior; (D) distal part of fourth pleopod, anterior; (E) uropod and telson, dorsal.

Figure 13. Orientomysis arenaria sp. nov. (A–J) Male (9.6 mm), holotype, NSMT-Cr 15618; (K) female (17.8 mm), paratype, NSMT-Cr 15619. (A) Third thoracic limb, posterior; (B) eighth thoracic limb, posterior; (C) penis, lateral; (D–H) first to fifth pleopods; (I) basal part of uropod, ventral; (J, K) uropod and telson, dorsal.