Epinephelus tankahkeei, a new species of grouper (Teleostei, Perciformes, Epinephelidae) from the South China Sea Author Wu, Haohao Marine Biodiversity and Global Change Research Center, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China https://orcid.org/0000-0003-4610-2566 Author Qu, Meng Marine Biodiversity and Global Change Research Center, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China Author Lin, Hungdu The Affiliated School of National Tainan First Senior High School, Tainan, Taiwan https://orcid.org/0000-0002-2841-1886 Author Tang, Wei Marine Biodiversity and Global Change Research Center, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China Author Ding, Shaoxiong Marine Biodiversity and Global Change Research Center, College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China & Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266200, China sxding@xmu.edu.cn text ZooKeys 2020 933 125 137 http://dx.doi.org/10.3897/zookeys.933.46406 journal article http://dx.doi.org/10.3897/zookeys.933.46406 1313-2970-933-125 B1A5BC7385F145839F4693B844736F36 8D09F8D3F5CD5A478630B8D943B7819B Epinephelus tankahkeei sp. nov. Figs 1 , 2 ; Table 1 Type material. Holotype : ZMUA-eptan06, 244.5 mm SL, Caught in Yongxing Island, Sansha, Hainan, 2 April 2017. Paratypes : ZMUA-eptan01, 111.0 mm SL, China, purchased at a fish market in Xiamen, Fujian, China, 1 September 2011, reported as collected in the south Taiwan Strait; ZMUA-eptan02, 233.2 mm SL, purchased at the Bashi market in Xiamen, Fujian, China, 22 August 2016, reported as collected in the south Taiwan Strait; ZMUA-eptan03, 215.4 mm SL, collected with the ZMUA-eptan02; ZMUA-eptan04, 262.5 mm SL, purchased at a fish market in Shenzhen, Guangdong, China, 15 February 2017, reported as collected in the South China Sea; ZMUA-eptan05, 232.6 mm SL, collected with the holotype; ZMUA-eptan07, 252.9 mm SL, purchased at a fish market in Shenzhen, Guangdong, China, 1 July 2017, reported as collected in the South China Sea; ZMUA-eptan08, 274.2 mm SL, China, purchased at a fish market in Xiamen, Fujian, China, 31 July 2018, reported as collected in the south Taiwan Strait. ZMUA-eptan09, 186.5 mm SL, China, purchased at a fish market in Haikou, Hainan, China, 22 March 2019, reported as captured using a trawl net in Mulan Bay, Wenchang, Hainan. Figure 1. Epinephelus tankahkeei a holotype, ZMUA-eptan06, 244.5 mm SL, Xisha Islands from the South China Sea b preserved holotype c paratype, ZMUA-eptan02, 233.2 mm SL, purchased at the Bashi market in Xiamen, Fujian, China, 22 August 2016. Figure 2. Epinephelus tankahkeei sp. nov. Radiograph of paratype ZMUA-eptan08, 274.2 mm SL. Diagnosis. Epinephelus tankahkeei sp. nov. can be distinguished from all other Indo-Pacific Epinephelus species by the following characteristics: dorsal-fin rays XI, 16-18 (vs. 14-15 in Epinephelus gabriellae ); anal-fin rays III, 8; pectoral-fin rays 16 or 17; lateral-line scales 47-51 (vs. 65-72 in Epinephelus polylepis ); caudal fin convex (vs. slightly emarginate or truncate caudal fin in E. chlorostigma , Epinephelus areolatus , Epinephelus bleekeri , and Epinephelus geoffroyi ); anal fin rounded (vs. angular anal fin in E. chlorostigma , and E. geoffroyi ); membranes of spinous portion of dorsal fin slightly incised; head (except chest), body (except abdomen), and fins (pectoral fin spotted only basally) with numerous, irregular, close-set, dark brown spots, becoming more widely spaced on the lower part, the ground color forming a pale network (vs. lager spots in Epinephelus miliaris , and E. areolatus ); rear margin of the caudal fin without a narrow white line (vs. a clear white margin posteriorly on the caudal fin in E. chlorostigma , and E. areolatus ). Description. Dorsal-fin rays XI, 16 (16-18); anal-fin rays III, 8; pectoral-fin rays 16 (16 or 17); lateral-line scales 51 (47-51); lateral scale series 123 (111-123); gill rakers 10 (10-11) +15 (14-16); vertebra 24; body slightly elongated and body depth less than head length. Body depth contained 3.2 (3.0-3.2) in standard length. Body laterally compressed and body width 2.6 (2.1-2.6) in body depth. Head length 2.7 (2.5-2.7) in SL; orbit diameter 6.1 (4.9-6.8) in head; snout length 3.8 (3.6-4.0) in head. Dorsal profile of head nearly straight except at the snout with a slight notch before eyes. Interorbital region convex, width 6.3 (5.6- 7.2) in head; preorbital depth 7.8 (7.8-11.3) in head; caudal-peduncle length 1.9 (1.8-2.2) in head; caudal-peduncle depth 3.3 (3.2-3.7). Mouth large and lower jaw slightly projecting and oblique. Lower jaw 3.4 (3.4-3.9) in head length; upper jaw 2.4 (2.3-2.5) in head. Maxilla slightly extending to rear edge of eye and posterior edge of maxilla slightly rounded. Maxilla width 8.1 (7.9-9.2) in head. One or two pairs of canine teeth at anterior part of the upper and lower jaw. Teeth of lower jaw form two rows and expand anteriorly into three rows; teeth in the outer side are larger than the inner side. Villiform teeth present on vomer and palatines. Tongue slender and sharp at tip. Longest gill raker was greater in length than longest gill filament. Nostrils round and posterior nostril larger than anterior nostril. Anterior nostril with a membranous flap. Three spines on operculum, topmost and undermost small, the middle the largest. Tip of middle spine extending farther towards tail than tip of lower spine. Upper edge of opercular membrane slightly convex coming to a rounded point posteriorly. Preopercle rounded with four to five prominent spines at angle and with numerous fine serrae while increasing in size downward. Lateral line starting from posterior opercle and slightly arched over pectoral region. Scales on head, thorax, abdomen, anterodorsal part of body and fin membranes weakly ctenoid. Auxiliary scales absent. Small scales present on inner margins of dorsal, pectoral, pelvic, and caudal fins and not extending to the rear margin area. Origin of dorsal fin before pectoral-fin base. Membranes of spinous portion of dorsal fin slightly incised. First dorsal spine contained 1.9 (1.6-2.0) times in second spine; second spine 1.2 (1.2-1.5) times in longest spine (third and fourth spine); longest spine contained 2.6 (2.6-3.1) in head length. Longest soft dorsal ray 2.4 (2.3-2.8) in head. Anal-fin origin below origin of first soft dorsal ray. First anal spine 2.0 (1.9- 2.3) times in second anal spine; second anal spine 1.2 (1.1- 1.4) times in third anal spine; third anal spine longest 3.5 (3.0-4.1) in head. Longest anal-fin rays 2.1 (1.9-2.5) in head. Caudal fin convex, 1.7 (1.6-2.0) in head. Middle pectoral rays longest, 1.8 (1.7-1.9) in head and reaching to base of 9th dorsal spine. Origin of pelvic fin slightly posterior to pectoral-fin base. Table 1. Meristics and measurements for type specimens of Epinephelus tankahkeei and E. chlorostigma . The dashes indicate that data were not collected due to specimen damage, which prevented an accurate measurement or count.
- Epinephelus tankahkeei E. chlorostigma
ZMUA-eptan06 (holotype) Range for all type specimens ANSP 103722 ANSP 163245
Standard length (mm) 244.5 111-274.2 281 398
Total length (mm) 286.2 136.5-334.7 355 503
Dorsal-fin ray count XI, 17 XI, 16-18 XI, 16 XI, 16
Anal-fin ray count III,8 III,8 III,8 III,8
Pectoral-fin ray count 16 16-17 18 17
Pelvic-fin ray count I+5 I+5 I+5 I+5
Lateral line scales 51 47-51 52 58
Lateral scale series 123 111-123 102 106
Gill rakers count 10+15 10-11+14-16 9+14 8+18
% of SL - - - -
Body depth 31.1 31.1-33.7 34.9 35.6
Body width 12.2 12.2-15.6 16.3 18.1
Head length 37.1 36.9-39.6 38.7 39.2
Snout length 9.8 9.5-10.9 10.0 10.1
Orbit diameter 6.1 5.7-8 7.5 6.1
Preorbital depth 4.8 3.5-4.8 4.7 4.5
Interorbital width 5.8 5.5-6.7 7.2 8
Maxilla width 4.6 4.1-4.8 4.9 5.1
Upper jaw length 15.6 15.6-17.1 18.0 17.5
Lower jaw length 11 8.6-11.5 12.4 11.7
Caudal peduncle depth 11.1 10.5-12.1 11.9 10.8
Caudal peduncle length 19.2 18-21.1 20.0 22.7
Predorsal length 34.6 32.4-38.8 36.4 36.5
Preanal length 63.4 58.5-69.1 68.7 73.9
Prepelvic length 36.8 34.8-40.8 38.8 34.7
Dorsal-fin base 53.4 53.1-61.4 59.4 54.8
Longest hard dorsal ray 14.3 12.4-14.4 15.7 14.3
Longest soft dorsal ray 15.2 13.4-16.9 14.5 15.4
Anal-fin base 15 14.8-17.3 15.4 16.2
Third anal spine length 10.7 9.3-13.3 10.0 8.1
Longest anal soft ray 17.3 14.9-21.1 15.7 15
Caudal-fin length 22.1 18.7-24.2 25.5 22.3
Pectoral-fin length 20.1 19.6-23.2 20.9 20.2
Pelvic-fin length 19.5 18.1-21.7 20.4 17.4
Pelvic spine length 11 9.7-12.6 10.4 9.2
Coloration in life (based on photographs of the fresh holotype and paratypes). Head (except chest), body (except abdomen), and fins (pectoral fin only basally) with numerous, irregular, close-set, dark brown spots becoming more widely spaced on the lower part and with the ground color forming a pale network (Fig. 1a ); dorsal fin, caudal fin and anal fin dark brown; pectoral fin translucent with reddish brown to light yellowish-brown; body sometimes with four faint, irregular, discrete dark bars; rear margin of the caudal fin without a narrow white line. Coloration in preservative. Body yellowish-brown to tan with close-set spots remaining prominent or faded (Fig. 1b, c ). Dorsal, caudal, and anal fins dark brown. Pectoral fin pale and opaque. Genetic analyses. Mitochondrial COI gene sequences were obtained from nine specimens of E. tankahkeei . Several sequences of related species were also sequenced in this study or obtained from GenBank. E. tankahkeei has 13 species-specific mutations at nucleotide positions 126, 216, 222, 249, 276, 372, 414, 519, 525, 528, 558, 567, and 576 (Table 2 ). The intraspecific mean distance of E. tankahkeei was 0.0028. The interspecific mean distances indicated that E. tankahkeei differs from E. chlorostigma by 0.0621, from E. polylepis by 0.0771, from E. gabriellae by 0.1263, from E. miliaris by 0.0904, from E. geoffroyi by 0.1219, and from E. areolatus by 0.0855 (Table 3 ). Phylogenetic trees using both maximum likelihood and Bayesian inference showed almost complete agreement, with E. tankahkeei forming a monophyletic clade that excluded all other closely related species (Fig. 3 ). Figure 3. Bayesian phylogenetic tree of Epinephelus tankahkeei and closely related fish species. Numbers above nodes are Bayesian posterior probability values (left) and ML bootstrap values above 50 (right). Distribution and habitat. The new species was recently observed in the South China Sea and Taiwan Strait. Similar to other congeners, E. tankahkeei is a reef-associated species that feeds on fishes and invertebrates. Etymology. Epinephelus tankahkeei is named after Tan Kah Kee (1874-1961), who was a famous overseas Chinese educator, philanthropist, and social activist and the founder of Xiamen University and Jimei School, in honor of his significant contribution to the motherland. Table 2. Species-specific mutation sites in the COI gene for Epinephelus tankahkeei .
- Nucleotide position (beginning from 5' end)
126 216 222 249 276 372 414 519 525 528 558 567 576
Epinephelus tankahkeei T C C A C G G T G C T G C
Other closely related species in this study C A, G T T, C A A A A, G C G, A A, G, C A A, T
Table 3. Analysis of the intraspecific and interspecific (K2P model) distances, interspecific distances (in lower left) and standard errors (in upper right) based on the COI locus between Epinephelus tankahkeei and closely related species; IMD = Intraspecific mean distance; SE = standard error.
- Interspecific Mean Distance
Group Species N IMD SE 1 2 3 4 5 6 7
1 Epinephelus tankahkeei 9 0.0028 0.0010 - 0.0112 0.0100 0.0144 0.0123 0.0141 0.0122
2 E. polylepis 4 0.0031 0.0015 0.0771 - 0.0093 0.0144 0.0127 0.0136 0.0119
3 E. chlorostigma 6 0.0030 0.0013 0.0621 0.0545 - 0.0143 0.0110 0.0138 0.0110
4 E. gabriellae 2 0.0016 0.0015 0.1263 0.1142 0.1169 - 0.0148 0.0066 0.0154
5 E. miliaris 2 0.0000 0.0000 0.0904 0.0885 0.0730 0.1143 - 0.0143 0.0122
6 E. geoffroyi 2 0.0047 0.0026 0.1219 0.1073 0.1107 0.0321 0.1107 - 0.0143
7 E. areolatus 3 0.0031 0.0018 0.0855 0.0831 0.0641 0.1239 0.0918 0.1152 -