Rostanga bifurcata Rudman & Avern, 1989

Lee, Yucheol, Nam, Eunjung & Park, Hyun-Jong Kil and Joong-Ki, 2022, Morphological description and DNA barcode information of seven newly reported nudibranch species from Korea, Journal of Species Research 11 (2), pp. 102-107 : 106

6. Rostanga bifurcata Rudman & Avern, 1989 ( Fig. 1F )

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Rostanga bifurcata Rudman and Avern, 1989: 293-300 , figs. 1B, C, 2B, 3B, 7C, 8-11, 28; Debelius and Kuit- er, 2007: 247; Kil et al., 2020: 204, 205.

Material examined. 1 individual (MO00178866): Donji-ri , Saryang-myeon, Tongyeong-si, Gyeongsangnam-do, Korea, 34°50′10.97″N, 128°09′28.64″E, 07 April 2021 ; 1 individuals ( NIBRIV0000882547 ): Gageodo-ri , Heuksanmyeon, Sinan-gun, Jeollanam-do, Korea, 38°03′46.06″N, 128°05′40.55″E, 30 July 2020 .

Diagnosis. Body ovate, swollen (length 12 mm, width 5 mm), ground color orange to red. Rhinophore stalks smooth, with white tip, horizontally arranged lamellae on clubs. Mantle wide, covering an entire foot. Dorsal surface of mantle covered by caryophyllidia and ornamented by minute black or white specks. White specks arranged along the mantle edge. Gills seven to ten in number, tripinnate, arranged in a gill circle surrounding anus on dorsal surface of mantle.

GenBank accession number. OK143201.

Distribution. Korea, Hong Kong, Japan, Australia, Hawaii, Malaysia, Philippines (Indo-Pacific), Tanzania (Africa).

Remarks. Rostanga species are characterized by having reddish-orange body color and caryophyllidia, specialized sensory tubercles on the dorsal surface of mantle. R. bifurcata and R. orientalis are commonly found in the northwestern Pacific and morphologically very similar, but distinguished by the lamellae in rhinophores. R. bifurcata has horizontally arranged lamellae in rhinophoral clubs, while R. orientalis has rhinophoral lamellae that are vertically arranged.

Figures

Fig. 1. Images of seven Nudibranchia species in Korea. A, Dendronotus primorjensis Martynov, Sanamyan & Korshunova, 2015; B, Doto japonica Odhner, 1936; C, Trinchesia ornata (Baba, 1937); D, E, Antiopella fusca (O’Donoghue, 1924); F, Cadlina paninae Korshunova, Fletcher, Picton, Lundin, Kashio, N. Sanamyan, K. Sanamyan, Padula, Schrödi & Martynov, 2020; G, Rostanga bifurcata Rudman & Avern, 1989; and H, Goniodoridella savignyi Pruvot-Fol, 1933.