116KOREAN Song JOURNAL Hun Han, OF Maeng ICHTH JinYOLOGY Kim and, Vol. Choon 28, N Boko. 2, Song 116-120, June 2016 Received: March 28, 2016 ISSN: 1225-8598 (Print), 2288-3371 (Online) Revised: May 23, 2016 Accepted: June 25, 2016 First Record of a Velvetfish,Cocotropus masudai (Scorpaeniformes: Aploactinidae) from Korea By Song Hun Han, Maeng Jin Kim1 and Choon Bok Song2,* Jeju Fisheries Research Institute, National Institute of Fisheries Science (NIFS), Jeju 63068, Korea 1Fisheries Resources and Environment Division, West Fisheries Institute, NIFS, Incheon 22383, Korea 2College of Ocean Sciences, Jeju National University, Jeju 63243, Korea ABSTRACT A specimen of Cocotropus masudai (41.2 mm in standard length), belonging to the family Aploactinidae, was firstly collected from the eastern coastal waters of Jejudo Island, Korea by using a fish trap in July 2011. This species is characterized by having the following morphological traits: XII, 9 dorsal fin rays; I, 8 anal fin rays; 12 pectoral fin rays; I, 3 pelvic fin rays; five preopecular spines; five sensory pores present on lower jaw and isthmus tip beyond fifth sensory pore. This species is similar to C. izuensis except for the number of preopercular spines (five in C. izuensis vs. four in C. masudai) and the anterior position of the isthmus (well beyond the fifth lower jaw sensory pore vs. the tip mostly reaching to the pore). In Korea, C. masudai can be easily distinguished from the Erisphex pottii in having the dorsal fin with nine soft rays (vs. 10~14 for Erisphex pottii), anal fin with seven soft rays (vs. 10~13) and pelvic fin with three soft rays (vs. two). We propose new Korean names, “Dot-chi-sok” and “Dot-chi” for the genus and species, respectively. Key words: First record, Cocotropus masudai, Aploactinidae, Jejudo Island INTRODUCTION was collected by a commercial fish trap in the coastal waters of Jejudo Island on July 8, 2011. Although this The velvetfishes (family Aploactinidae), comprising 17 species named as “Dot-chi” in Korean, which was pro- genera with about 38 species, are widely distributed in posed by Myoung et al. (2002) based on the photograph tropical and temperate seas of the world (Nelson, 2006). of the species collected from the northern sea of Jejudo This family is characterized by having body covered Island, Korea. The morphological features of this species with prickly scales (some species lack prickles and have have not been reported in Korea until now. Therefore, the smooth skin), all fin rays unbranched, anal fin spines morphological characters of C. masudai were described usually indistinct (rarely pungent), anterior three to five based on the collected specimen and it was added to the dorsal fin spines usually divergent, either elevated or list of Korean fish fauna. Identification procedure of this largely devoid of connecting membrane (Poss, 1999; Nel- specimen was followed by the method of Hubbs and son, 2006). In Korea, one species, Erisphex pottii (Stein- Laglar (2004). The examined specimen is deposited at the dachner, 1896) in the family has been reported so far (Kim Fish Genetics and Breeding Laboratory of Jeju National et al., 2005). Univerisy (JNU), Korea. The genus Cocotropus Kaup, 1858, comprises 16 valid species worldwide (Froese and Pauly, 2016) and five Cocotropus Kaup, 1858 species from Japan (Nakabo and Kai, 2013). Recently, a (New Korean genus name: Dot-chi-sok) single specimen of Cocotropus masudai Matsubara, 1943 Coccotropus Kaup, 1858: 333 (type species: Corythobatus echinatus Cantor, 1849). * Corresponding author: Choon Bok Song Tel: 82-64-754-3471, Gill membranes free from isthmus; anus slightly anteri- Fax: 82-64-756-3493, E-mail: [email protected] or to anal fin origin; dorsal fin rays continuous and com- — 116 — http://www.fishkorea.or.kr First Record of Cocotropus masudai from Korea 117 Fig. 1. Cocotropus masudai, JNU-0387, 41.2 mm SL, fish trap, Hangyeong-myeon, Jejudo Island, Korea. prising a single fin; I, 3 pelvic fin rays; interorbital ridges Table 1. Morphological traits compared between present and previ- on the both sides running in parallel (Matsubara, 1943; ous study on C. masudai Morphological Masubara (1943) Poss, 1999). Present study characters (Holotype) Total length (mm) 52.0 50.0 Cocotropus masudai Matsubara, 1943 Standard length (mm) 41.2 (n=1) 40.5 (n=1) (Korean name: Dot-chi) In % of standard length (Fig. 1; Table 1) Head length 36.7 35.1 Cocotropus masudai Matsubara, 1943: 470 (type locality: Body depth at ventral 36.7 36.5 Izu Islands, south of Tokyo, Japan); Nakabo in Masuda In % of head length et al., 1984: 319 (Japan); Poss in Carpenter and Niem, Snout length 30.5 34.6 Orbital diameter 24.5 22.3 1999: 2356 (western central Pacific); Nakabo in Nako- Interorbital length 22.5 21.6 bo, 2002: 601 (Japan); Myoung et al., 2002: 78 (Korea). Upper jaw length 41.7 40.5 Counts Dorsal fin rays XII, 10 XII, 10 Material examined. JNU-0387, 41.2 mm standard Pectoral fin rays 12 - length (SL), fish trap, Hangyeong-myeon, Jeju-do, Ko- Pelvic fin rays I, 3 - rea. June 8, 2011. Anal fin rays I, 8 I, 8 Caudal fin rays 13 13 Description. Measurements of morphological traits for Lateral line pores 9 9 the present specimen are shown in Table 1. Measurements Gill rakers 2+6 2+6 are revealed as a percentage against SL: Body depth, 35.7; body width, 18.4; head length, 36.7; upper jaw, 15.3; snout length, 11.2; eye dimeter, 9.0; interorbital width, pressed, with many ridges, ridges smooth and covered 8.3; predorsal fin length, 11.4; prepectoral fin length, 29.4; with thin skin; profile very steep from first dorsal spine preanal fin length, 67.7; length of longest fifth dorsal fin to snout; mouth very oblique; posterior end of upper ray, 23.6; length of longest third pectoral fin ray, 21.8; jaw extending behind middle of eyes; villiform teeth on length of longest third anal fin ray, 16.3; caudal peduncle jaws; vomer and palatines toothless; five sensory pores length, 20.6; length of dorsal fin base, 83.3; length of present on lower jaw, first pores fused on both sides; gill pectoral fin base, 12.4; length of anal fin base, 23.5. membranes free from isthmus; isthmus tip slightly be- Body moderately compressed; body covered with small yond fifth sensory pores of lower jaw; snout about two pointed papillae, each underlain by tiny buried scales; times longer than orbital diameter; eye moderate and al- dorsal profile of head sloping suddenly; head small, com- most round; interorbital space with somewhat narrower 118 Song Hun Han, Maeng Jin Kim and Choon Bok Song Opecular spines Preopecular spines Fig. 2. The arrows indicate preopecular spines (black) and opecular spines (blue) on the head. and slightly convex; supraorbital and suborbital edges Cocotropus based on the morphological characters in the somewhat raised as low ridge; five spines and two spines dorsal fin rays which are continuous and comprising a on preoperculum and operculum, respectively (Fig. 2); single fin, I, 3 pelvic fin rays, and interorbital ridges on several sensory pores present surrounding eye; lateral the both sides running in parallel. Also the meristic and line well arched anteriorly, remaining part of lateral one morphometric characters of the present specimen were mostly straight; sensor pores present on anterior part of compared with those in the original report on C. masudai lateral line; origin of dorsal fin started above anterior of (Mastsubara, 1943; Table 1). As a result, our specimen eye, dorsal fin continuous, without notch between spine was well matched with most of morphological characters and sort part; the second spine and sixth soft ray the lon- reported before. They include XII, 9 dorsal fin rays, I, 8 gest in dorsal fin; soft dorsal fin extends base of caudal anal fin rays, 12 pectoral fin rays, four preopecular spines, fins; pectoral fin moderate, covered with papillae except five sensor pores present on lower jaw and isthmus tip for lower and posterior margins and not reaching to ori- beyond fifth sensory pore and measurements. However, gin of anal fin; pelvic fin slightly small, not reaching to there are some differences in snout length (30.5% in HL anus; origin of anal fin started below the second dorsal for the present specimen vs. 34.6% for Mastsubara, 1943) ray; caudal fin rounded and its basal portion covered with and orbital diameter (24.5% vs. 22.3%). These differenc- papillae; all soft fin rays unbranched. es seem to be intraspecific or geographic variation, but it Color when fresh. Body and head entirely brown needs further studies on geographic variation of the spe- mixed with reddish; many small dark spots on body and cies with more specimens. head; dorsal fin brown with irregular dark spots; pectoral C. masudai was firstly reported by Mastsubara (1943) fin brown with irregular dark marking, posterior margin based on a single specimen collected from Izu Islands, of pectoral fin yellow; pelvic fin pale brown; a single Japan. Senou (1990) and Masuda and Kobayashi (1994) dark line on ventral portion of anal fin, its posterior mar- subsequently reported this species from the Izu Peninsu- gin yellow; caudal fin brown with irregular dark spots, its la located in the southern Japan, as the second and third posterior margin yellow. record of the species, respectively. However, Imamura et Color after preservation. Body entirely pale brown; al. (2010) recently reported that the specimens collected irregular brown spots or blotch on dorsal fin; pectoral fin from the Izu Peninsula by Senou (1990) and Masuda and pale brown with irregular brown marking, posterior mar- Kobayashi (1994) are not C.