A report of four unrecorded species of opisthobranch molluscs from Korea Author Jung, Daewui Author Lee, Jongrak Author Kim, Chang-Bae text Journal of Species Research 2014 2014-02-28 3 1 1 6 http://dx.doi.org/10.12651/jsr.2014.3.1.001 journal article 10.12651/JSR.2014.3.1.001 2713-8615 8120252 Pleurobranchus weberi ( Bergh, 1905 ) ( Fig. 1B ) Oscanius weberi Bergh, 1905: 53-55 , pl. 2, fig. 1, pl. 6, fig. 1-6. Pleurobranchus weberi : Gosliner et al. , 2008: 99 . Materials examined. 1 individual, Mun-seom , Seogwi-dong , Seogwipo-si , Jeju-do , Korea , 1 April 2013 ( D. Jung ) (KOSPIV0000180756) . Description. Body ovate and large; body length 92 mm , width 78 mm in living animal; ground color light brown. Mantle widely spreads to covered whole foot; mantle edge slightly undulated. Dorsal markings milky white double rings around tubercles decrease in size toward to mantle edge. Translucent white lines on dorsal surface, short, irregular length. Dorsal tubercles small and round- ed; increase in number to edge of mantle. Rhinophores short and enrolled; upper half dark brown; joined basally. Oral veil reversely trapezoid; deeper in color to posteriorly. Gills on right side between mantle and foot; gills bipinnated with 25 pinnae alternated on each side; cen- B Fig. 2. Aplysiopsis nigra ( Baba, 1949 ) . A. dorsal view. B. ventral view. C. branchial papillae. D. ventral view of head and sole of foot. A-D. preserved specimen (body length: 23 mm, width: 4 mm). Scales=5 mm. tral axis dark. Foot wide; anterior unilabiate; metapodium short and blunted. Distribution. Korea , Indonesia , Philippines . Remarks. This species is similar to P. peronii in the external morphology but can be easily distinguished by following characteristics:

Species Character	P. peronii	P. weberi
Many tubercles
Dorsal tubercle	covering the entire	A few tubercles
dorsum
Several dark purple	Milky white
Dorsal marking	tips of tubercles,	double ring
and dark	patches

Many species in the genus Pleurobranchus show a variety of body coloration. A previous study ( Gosliner et al. , 2008 ) described this species as having a dark red ground color. Specimen examined in the present study showed a light brown ground color with several chocolate brown patches on the body except on the sole.