Roa haraguchiae Uejo, Senou et Motomura, 2020

Lee, Shu-Ling, Chiu, Yung-Chieh & Chen, Hong-Ming, 2022, First record of butterflyfish, Roa haraguchiae (Actinopterygii: Perciformes: Chaetodontidae), from northeast Taiwan, Acta Ichthyologica et Piscatoria 52 (2), pp. 141-148 : 141

Roa haraguchiae Uejo, Senou et Motomura, 2020

Figs 1 , 2

Specimens examined.

(six specimens) TOU-AE8100, 72.22 mm SL, Da-xi , NE Taiwan, bottom trawl, 8 May 2021 ; TOU-AE8354, 96.27 mm SL, Nan-fang-ao, NE Taiwan, bottom trawl, 1 Aug 2021 ; TOU-AE 8355, 108.59 mm SL, sharing the same collecting information with TOU-AE8354; TOU-AE8379, 96.78 mm SL, Da-xi , NE Taiwan, bottom trawl, 13 Aug 2021 ; TOU-AE8491, 90.21 mm SL, Da-xi , NE Taiwan, bottom trawl, 26 Oct 2021 ; TOU-AE8492, 98.25 mm SL, sharing the same collecting information with TOU-AE8491.

Comparative material.

Roa modesta (26 specimens): TOU-AE7862, 89.70 mm SL, Da-xi, NE Taiwan, date unknown; TOU-AE7863, 96.11 mm SL, Da-xi, NE Taiwan, date unknown; TOU-AE7876, 76.96 mm SL, Ba-dou-zi, NE Taiwan, 15 Aug 2020 ; TOU-AE7877, 84.71 mm SL and TOU-AE7878, 90.11 mm SL sharing the same collecting information with TOU-AE 7876; TOU-AE7995, 80.30 mm SL, Dong-gang , S Taiwan, 2 Jan 2021 ; TOU-AE7999, 86.50 mm SL, Dong-gang, S Taiwan, 23 Jan 2021 ; TOU-AE8000, 75.58 mm SL, Ke-tzu-liao, S Taiwan, 24 Jan 2021 ; TOU-AE8011, 43.91 mm SL sharing the same collecting information with TOU-AE8000; TOU-AE8109, 86.78 mm SL, Kan-zi-ding Fish Market , N Taiwan, 27 Apr 2021 ; TOU-AE8110, 92.98 mm SL sharing the same collecting information with TOU-AE8109; TOU-AE8131, 95.76 mm SL, Da-xi , NE Taiwan, 26 Jul 2020 ; TOU-AE8132, 91.31 mm SL sharing the same collecting information with TOU-AE8131; TOU-AE8133, 97.54 mm SL, Da-xi , NE Taiwan 1 May 2021 ; TOU-AE8241, 63.40 mm SL, Ke-tzu-liao, S Taiwan, 24 Jan 2021 ; TOU-AE8242, 54.87 mm SL, Ke-tzu-liao, S Taiwan, date unknown; TOU-AE8243, 72.98 mm SL and TOU-AE8244, 79.78 mm SL, Ke-tzu-liao, S Taiwan, date unknown; TOU-AE8287, 91.96 mm SL, Da-xi , NE Taiwan, 26 Jul 2021 ; TOU-AE8288, 90.82 mm SL sharing the same collecting information with TOU-AE8287; TOU-AE8322, 98.68 mm SL, Nan-fang-ao, NE Taiwan, 1 Aug 2021 ; TOU-AE8323, 94.74 mm SL and TOU-AE8324, 98.55 mm SL sharing the same collecting information with TOU-AE8322; TOU-AE8372, 74.76 mm SL, Ba-dou-zi, NE Taiwan, 2 Aug 2021 ; TOU-AE8373, 71.30 mm SL sharing the same collecting information with TOU-AE8372; TOU-AE8426, 77.42 mm SL, Da-xi , NE Taiwan, 13 Aug 2021 .

Diagnosis.

Specimens of Roa haraguchiae in Taiwan with the following combination of characters: pored lateral-line scales 39-42; non-pored lateral-line scales 4-6; scale rows above lateral line 11-13, scale rows below lateral line 20-24; scale rows under longer axis of black blotch on dorsal-fin soft-rayed portion 10-12; longer snout length 2.8-3.0 in HL; shorter caudal-peduncle depth 8.8-10 in SL; shorter dorsal-fin soft-rayed portion base length 2.7-2.9 in SL; longer 2nd anal-fin spine length 3.7-4.0 in SL; anterior margin of second body band not reaching anteroventrally to pelvic-fin spine base; first pelvic-fin soft ray white and extended; membranes associated with first and second dorsal-fin spines are respectively blackish completely and distally.

Description of Taiwanese specimens.

Counts and proportional measurements as a percentage of SL and HL are given in Table 2 . Data for the specimens in Taiwan, followed by data for the other congeners. Dorsal-fin XI, 20-21; anal-fin III, 16-17; pelvic-fin rays I, 5; pectoral-fin rays 14; pored lateral-line scales 39-42; Non-pored lateral-line scales 4-6; Scale rows above lateral line 11-13; Scale rows below lateral line 20-23; Scale rows in longer axil of black blotch on dorsal-fin soft-rayed portion 11-12; gill rakers 3-4 + 11-12 (14-16); vertebrae 11 + 13 = 24; caudal rays 12 + 11 = 23.

Body strongly deep and compressed, its depth 1.5-1.7 in SL and width 6.4-7.2 in SL; head length 2.6-2.8 in SL; orbit diameter slightly shorter than snout length, its length 3.0-3.3 in HL; snout length 2.8-3.0 in HL; postorbital length 2.8-3.1 in HL; interorbital region narrow, bony width 3.5-4.0 in HL. Mouth small, terminal, and slightly protractile. Numerous bristle-like teeth in both jaws. Opercular membranes narrowly attaching to isthmus, slightly projecting at posterior margin of operculum; gill rakers short. Two pairs of nostrils closely symmetric, anterior to eye.

Scales on body ctenoid, also scattered on head, abdomen, and part of upper jaw, except lower jaw. Lateral line scales ascending from posterior edge of gill opening to divide between white and brown bands below base of eleventh dorsal-fin spine and then gradually declining to end of dorsal-fin.

Dorsal-fin spinous portion base length 2.5-2.7 in SL, soft-rayed portion base length 2.7-2.9 in SL; origin of dorsal-fin at vertical through base of pectoral-fin, well at origin of pelvic-fin. First dorsal-fin spine shortest, its length 11.9-14.7 in SL; second dorsal-fin spine length 5.1-8.3 in SL; third dorsal-fin spine slightly shorter than fourth spine, its length 2.9-3.2 in SL; fourth dorsal-fin spine longest, its length 2.8-3.2 in SL; after that, spine length becomes shorter when spine number increasing.

First dorsal-fin soft ray length 4.1-4.9 in SL. Pectoral-fin moderately long, its length 3.1-3.5 in SL, first ray not segmented, second or third ray longest and reaching through posterior edge of second band. Pelvic-fin origin below pectoral-fin base origin, its spine length 3.7-4.7 in SL; its soft ray length 3.1-4.0 in SL. Second anal-fin spine longest, its length 3.7-4.0 in SL; longest anal-fin soft ray length 4.0-4.6 in SL. Caudal-fin truncated, its length 4.1-5.1 in SL.

Coloration.

In fresh specimens (Figs 2A-D ): head and body white, with three main brown bands. First band starting from origin of dorsal fin and descending through eye to lower edge of preopercle, with width slightly shorter than orbit diameter. Second band extending from base of second to seventh dorsal-fin spines down to base of pelvic-fin soft rays, posterior margin to anus. Third band starting from base of tenth dorsal-fin spine to terminal end of dorsal-fin, downwards almost covering soft anal fin, between third or fourth soft rays and terminal end of anal-fin. Two additional narrow brown bands also visible; one on anterior margin of body, extending from tip of upper snout through interorbital, approximately half of predorsal-fin length. Another narrow band on posterior margin of caudal-peduncle in form of black blotch with white edge between first and seventh dorsal-fin soft rays. Dorsal-fin spines and soft rays whitish, except for those blackish banded areas and membranes associated with first and second dorsal-fin spines. Anal-fin spines and soft rays whitish, except those banded areas. Caudal-fin and pectoral-fin greyish. Pelvic-fin spine and first soft ray whitish, while others brownish.

When preserved (Fig. 3 ): Head and body change from whitish to slightly yellowish, with three brown bands becoming lighter. Opercle brownish; opercular membrane yellowish; membranes associated with first and second dorsal-fin spines blackish; blotch on soft-rayed portion blackish, with still obvious whitish margin. The fin color is approximately the same as described above in color when fresh.

Figures

Figure 1. Distribution records of Roa haraguchiae from Taiwan. Black point symbols collection port, A = Da-xi, B = Nan-fang-ao. Red point means fishing location.

Figure 2. Comparison of the morphological differences of the fresh specimens of Roa haraguchiae in Taiwan, for which CO 1 genes were sequenced. A. TOU-AE 8100, 72.22 mm SL; B. TOU-AE 8354, 96.27 mm SL; C. TOU-AE 8355, 108.59 mm SL; D. TOU-AE 8379, 96.78 mm SL. Photo by J. - F. Huang.

Figure 3. Preserved specimens of Roa haraguchiae. The band coloration turns slightly brownish and the blackish part has remained.