Trapania euryeia Gosliner & Fahey, 2008

Jung, Dae-Wui, Kil, Hyun Jong, Nam, Eunjung & Kim, Hyeonggeun Kim and Chang-Bae, 2022, Redescription of three trapanian nudibranchs (Nudibranchia, Goniodorididae) from Korea with a key to the species, Journal of Species Research 11 (3), pp. 169-173 : 170-172

Trapania euryeia Gosliner & Fahey, 2008

úNjẕnj갯ḓḝḵḍḑ ( Fig. 1 )

Trapania euryeia Gosliner & Fahey, 2008: 75 - 78 , figs. 1I, 18, 19, 35B; Gosliner et al., 2008: 133; 2015: 144; Kil et al., 2020: 230, 231.

Trapania brunnea Ono, 1999: 75 .

Type locality. Madang, Papua New Guinea .

Distribution. Korea, Japan, Reunion, Indonesia, Papua New Guinea, Marshall Islands, USA ( Midway Atoll and Hawaii), and Australia ( Gosliner and Fahey, 2008; Gosliner et al., 2008; Kil et al., 2020).

Material examined. 1 individual (NIBRIV0000836104), Wangdolcho , Hupo-ri , Hupo-myeon, Uljin-gun, Gyeongsangbuk-do, Korea, 30 August 2018, coll. H.J. Kil, E. Nam and H. Kim, with SCUBA .

Description. Body limaciform, convex, and slightly widen- ed around the gill. The body length of the preserved specimen 4 mm. Ground color milky white. Relatively large in size and irregular-shaped brown markings broadly cover the dorsal surface; numerous white specks present on the inside of these brown markings ( Fig. 1A, B ). The tip of rhinophores translucent white. Clavus with nine lamellae, the anterior part of the upper one-third of the clavus orange in color, the rest of the clavus opaque white with brown patches. Stalk smooth, thick, and translucent. A pair of extra-rhinophoral appendages present each side of the head, next to the rhinophores ( Fig. 1C ); smooth, long, blunt end, curved upward, translucent with brown patches and white specks. Gill relatively large, consists of four bipinnate branches ( Fig. 1D ). Branchial leaves pale brown with white specks. Branchial leave rachis translucent white. Extra-branchial appendages relatively short, smooth, blunt end, and bent backward. Oral tentacles smooth; the tip of oral tentacles translucent white. Tentacular foot corners smooth, pointed end. The length of oral tentacle and tentacular foot corners approximately same. Metapodium long, yellow marking present on metapodium end, the tip of metapodium pointed and translucent white.

Remarks. Gosliner & Fahey (2008) described that this species has seven to eight lamellae on clavus of rhinophore and three gill branches, while nine lamellae and four gill branches are observed in the specimen examined here. All other characteristics are consistent with those from the original description.

* Trapania japonica (Baba, 1935) Ḇẕnj 갯ḓḝḵḍḑ (ljÿ) ( Fig. 2 )

Drepania japonica Baba, 1935: 336 - 338 , text fig. 4 (cited from Baba, 1990).

Trapania japonica (Baba, 1935) Rudman, 1987: 197 - 201 , figs. 3C, 7a, 8, 9; Baba, 1990: 8, 9, figs. 1 - 3.

Type locality. Mutsu Bay , Aomori, Japan .

Distribution. Korea, China ( Hong Kong), Japan, Australia ( Rudman, 1987; Baba, 1990).

Material examined. 1 individual (NIBRIV0000868685), Janggil-ri , Guryongpo-eup , Nam-gu, Pohang-si, Gyeongsangbuk-do, Korea, 8 August 2019, coll. C.Y. Park, with SCUBA .

Description. Body limaciform and convex ( Fig. 2A, B ). The body length of the preserved specimen 7 mm. Ground color translucent white. Brown colored rounded or ringed patches present from head to metapodium except for the appendages and the foot. Rhinophores translucent white ( Fig. 2C ). Clavus with eleven lamellae. Stalk smooth, thick, and relatively short. A pair of extra-rhinophoral appendages present next to the rhinophores; smooth, long, pointed end, bent backward, and upper half yellow in color. Gill consists of three bipinnate branches and translucent. Extra-branchial appendages relatively short, smooth, pointed end, curved upward, and upper half yellow in color ( Fig. 2D ). Oral tentacles smooth and translucent white. Tentacular foot corners smooth and pointed end. Oral tentacle slightly longer than tentacular foot corner. Metapodium long, metapodium end pointed.

Remarks. Baba (1935) did not properly record the body color and pattern in the dorsal patches of T. japonica because of the use of fixed specimens. The specimens used in this study had the same characteristics as the original description, except for body color and pattern. Afterward, Rudman (1987) recorded the body color of T. japonica for the first time using specimens collected from Hong Kong and Australia. The specimen examined here is similar to the specimen obtained from Hong Kong rather than the Australian specimen by Rudman (1987) in that the brown markings on the dorsal surface are relatively small in size and light brown in color.

Figures

Fig. 1. Trapania euryeia Gosliner & Fahey, 2008. A. Dorsal view, living animal and its habitat; B. Dorso-lateral view; C. Rhinophore and extra-rhinophoral appendage on the right side of the head; D. Gill and metapodium;A-D. live animal photographs. Scale bars=1mm.Abbreviations: rh, rhinophore; era, extra-rhinophoral appendage; ot, oral tentacle; fc, foot corner; dm, dorsal marking; g, gills; eba, extra-branchial appendage; mp, metapodium.

Fig. 2. Trapania japonica (Baba, 1935).A. Dorsal view; B. Dorso-lateral view; C. Rhinophore and extra-rhinophoral appendage on the right side of the head; D. Extra-branchial appendage; A-D. live animal photographs. Scale bars=1 mm. Abbreviations are same to those in the Fig. 1. Photo by Chan-yong Park.