Sinibrama longianalis, Xie & Xie & Zhang, 2003

Xie, Zhong-Gui, Xie, Cong-Xin & Zhang, E, 2003, Sinibrama Longianalis, A New Cyprinid Species (Pisces: Teleostei) From The Upper Yangtze River Basin In Guizhou, China, Raffles Bulletin of Zoology 51 (2), pp. 403-411 : 404-410

Sinibrama longianalis , new species

( Fig. 2 )

Sinibrama macrops – Luo & Chen, 1998: 145 (Wu Jiang in Guizhou, China)(not Günther, 1868).

Material examined. – Holotype – ( IHB 6650583 ) 134.3 mm SL; Xiang Jiang (a stream tributary flowing to the Wu Jiang of the upper Yangtze River basin) in Zunyi, Guizhou, China, coll. R. D. Lin, P. Q. Yue & W. Chen, May.1966.

Paratypes – 24 ex. ( IHB 6650559 , 650554 , 6650587 , 6650572-5 , 6650561 , 6650577-9 , 6650600 , 6650596-7 , 6650602-03 , 6650566- 7 , 6650589-94 ) 110.6- 171.6 mm SL , 1 ex. ( ZRC 6650601 ), 111.9 mm SL, all data same as holotype ; 2 ex. ( IHB 87 VI225 , 87 VI256 ), 119.6-128.6 mm SL, Qingshui Jiang (a stream tributary flowing to the Wu Jiang of the upper Yangtze River basin) in Kaiyang, Guizhou, coll. D. Z. Wang, Jun.1987 .

Diagnosis. – Sinibrama longianalis is distinguished from all other congeners by possessing the following combination of characters: last simple dorsal-fin ray well-ossified; a snout shorter than eye diameter; lateral line scales 56-64 (mean 59.5); circumpeduncular scales 18-21; eye diameter 27.1- 31.6 % HL; anal fin with 24-28 (mean 25.2) branched rays, originating opposite to or slightly in advance of posterior end of dorsal-fin base, basal length 27.0-31.1% SL; pectoral fin reaching to or slightly beyond pelvic-fin insertion.

Description. – Meristic and morphometric data of 28 specimens, 110.6-171.6 mm SL in Tables 1 -2 and general appearance in Fig. 2 .

Body strongly compressed and moderately deep, dorsal profile convex with a slight hump posterior to nape and ventral profile somewhat round. Head roughly triangular, longer than deep, dorsally straight, with a slightly convex interorbital space. Snout blunt, shorter than eye diameter. Eye large, laterally positioned in anterior half of head, diameter equal to interobital width. Mouth terminal, oblique, no small knob at lower jaw symphysis. Maxillary reaching somewhat beyond nostril, but not to anterior margin of orbital. No barbel. Abdominal keel present between pelvic-fin and anus.

Dorsal fin with 3 simple and 7-8 branched rays, last branched ray split to base and last simple ray well-ossified and shorter than HL, origin in halfway between snout tip and caudal-fin base or slightly moved forwards, distal margin slightly concave or truncate. Pectoral fin falcate, with 1 simple ray and 13-16 branched rays, shorter than HL, reaching slightly beyond pelvic-fin origin when depressed. Pelvic fin broadly pointed, with 1 simple ray and 8 branched rays, shorter than HL, inserted midway between pectoral- to anal-fin origin, not reaching anal-fin origin when depressed. Anal fin with 3 simple and 24-28 branched rays, last one split to base, origin vertically opposite to or somewhat in advance of posterior end of dorsal-fin base, distal margin concave. Caudal fin forked, longest rays more than 2 times as long as shortest rays.

Lateral line complete, with 56-64 perforated scales, bent ventrally before pelvic-fin origin and running parallel with ventral margin to anal-fin origin, then increasingly directed dorsally and finally extended mid-laterally along caudal peduncle. Scale rows above lateral line 11-12 and below 6- 7. Predorsal scales irregularly arranged; circumpeduncular scales 18-21. Axillary scale long, reaching beyond base of last ray. First gill arch on left side of body with 12-15 short, small and sparsely-set gill rakers. Pharyngeal teeth triserial, somewhat compressed with pointed and curved tips. Gas bladder bipartite, anterior chamber elliptical, posterior chamber slender with a round distal end, 1.5 times as long as anterior chamber.

Coloration. – In formalin-stored specimens, body yellowish, somewhat darker above, a streak of very minute black dots above lateral line to base of caudal fin.

Distribution. – Sinibrama longianalis is so far known only from the Xiang Jiang in Zunyi and the Qingshui Jiang in Kaiyang, two stream tributaries flowing to the Wu Jiang (upper Yangtze River basin) in Guizhou Province, China ( Fig.3 ).

Etymology. – The name is made from the Latin longus (long) and analis (anal fin), meaning a long anal-fin base.

Remarks. – Sinibrama longianalis is closely associated with S. macrops and S. wui by having a snout shorter than eye diameter, a well-ossified last simple ray of dorsal fin, lateral line scales 56-64 and circumpeduncular scales18-21. As mentioned above, the taxonomy of S. macrops and S. wui is still controversial and in need of revision. But this is not the place to address this problem in depth. For convenience of comparison, we provisionally retain both as two valid species, as currently understood by Chinese authors. Sinibrama longianalis differed from S. macrops and S. wui in six meristic characters studied ( Table 1). Although these differences were highly significant (t- test, p<0.05), there were no gaps in the distributions of characters from S. longianalis compared with S. macrops and S. wui when the distribution of each character was examined. Therefore, there is no single character that discriminates S. longianalis from both S. macrops and S. wui .

Two characters displaying the least amount of overlap between S. longianalis and S. wui or S. macrops were the numbers of the branched anal-fin rays and scale rows above the lateral line. Sinibrama longianalis had 24–28 branched anal-fin rays in the studied specimens. Four specimens with 24 and one specimen with 25 branched anal-fin rays were found in twenty-six studied specimens of S. macrops , however. These five specimens had 10 scale rows above the lateral line and 20-21 circumpeduncular scales, both typical of S. macrops . Among one hundred and twelve studied specimens of S. wui , there were two specimens having 24 branched anal-fin rays, but the values of other meristic characters in these two specimens were characteristic of S. wui and not of S. longianalis : 57 lateral line scales and 10 scale rows above the lateral line. All studied specimens of S. longianalis had 11-12 scale rows above the lateral line. In contrast, three specimens having 11 scale rows above the lateral line were found in S. macrops , but they had 22-23 branched anal-fin rays typical of S. macrops and not of S. longianalis . While most studied specimens from S. wui had 9-10 scale rows above the lateral line, there were twentytwo (19.8 % of the total) specimens whose scale rows above the lateral line are 11, falling within the range of the same meristic character in S. longianalis . These specimens had 18-22 branched anal-fin rays characteristic of S. wui . When the numbers of the branched anal-fin rays, lateral line scales and scale rows above the lateral line were graphed as a threedimensional distribution ( Fig. 4 ), there was a distinct separation between the studied specimens of S. longianalis and those so far identified as S. wui and S. macrops . Furthermore, this separation was displayed by the principal component analysis (PCA) that was performed on 31 measurements that were made from 165 studied specimens.

The studied specimens of S. longianalis , S. wui and S. macrops were analyzed with PCA on the correlation matrix of log 10 -transformed measurements (Table 2 and Fig. 5 ). PC1 (the first principal component) is considered as a general size axis ( Marcus, 1990; Schaefer, 1991). The similarity of character loadings on PC1 (Table 3) confirmed this interpretation for our data set. PC2, the main shape axis (James & McCulloch, 1990) in our analysis, separates S. longianalis from both S. wui and S. macrops ( Fig. 5 ). PC3, another shape axis, doesn’t allow separation of S. longianalis from S. wui and S. macrops .

There are six characters with main loadings on PC2: snout length, eye diameter, anal-fin basal length, distance from the pectoral- to pelvic-fin origin, distance from the anal-fin origin to the dorsal origin of the caudal fin, and distance from the anal-fin origin to the ventral origin of the caudal fin (characters 4, 5, 13, 20, 29 and 30 in Table 3). In order to estimate the importance of the measurements for species identification, we conducted a univariate analysis of these six measurements expressed as percentages of SL or HL (characters 4 and 5 of HL and others of SL) comparing S. longianalis with each of S. macrops and S. wui . All of them showed significant differences (t-test) in mean values of the indexes. However, only two characters (5 and 13) in S. longianalis were found to have a gap in their distributions of indexes compared with S. wui and S. macrops . Apparently, both are useful characters for identification of S. longianalis . It is distinct from S. macrops and S. wui in having a smaller eye (diameter 27.1-31.6 % of HL vs. 32.1-39.4) and a longer anal-fin base (length 27.0- 31.1% SL vs. 21.3-26.8). Three other characters (20, 29 and 30) in S. longianalis overlapped in their distributions of indexes compared with S. macrops and S. wui . Nevertheless, the mean value of the index was shorter in S. longianalis for character 20. This means that S. longianalis has a shorter distance from the pectoral- to pelvic-fin insertion than both S. macrops and S. wui . Our examination showed that S. longianalis has a depressed pectoral fin reaching to or slightly beyond the pelvic-fin insertion (vs. not reaching), by which it can be distinguish from both S. wui and S. macrops . The mean values of the indexes were higher in S. longianalis for characters 29 and 30, indicating that it has a more forward positioned anal-fin origin compared with both S. macrops and S. wui . Our observation confirmed that the anal-fin origin in S. longianalis is vertically opposite to or slightly in advance of the posterior end of dorsal-fin base (vs. far behind), a character easily used to distinguish it from S. wui and S. macrops .

Comparative material. – Sinibrama wui : IHB 74 VI1396-9 , 74 VI1340-5 , 10 ex., 92.9-146.2 mm SL, Min Jiang in Ninghua , Fujian . IHB 74 VI2726 , 74 VI723-4 , 3 ex., 101.9-109.4 mm SL, Min Jiang in Jian’ou, Fujiang . IHB 825185 , 825042 , 2 ex., 107.7- 136.4, Min Jiang , Fujian . IHB 574181-2 , 2 ex.,110.0- 116.4 mm SL, Min Jiang in Nanping , Fujian . IHB 74 VI2459-62 , 4 ex., 79.5- 132.0 mm SL, Min Jiang in Jianyan , Fujian . IHB 74 IX4201-4, 74IX 4206-13, 12 ex., 91.6 -127.4 mm SL, Ou Jiang in Lishui , Zhejiang . IHB 74 IX4111, 74IX4113-9, 8 ex., 112.5-157.2 mm SL, Ling Jiang in Linhai , Zhejiang . IHB 74 IX3946-8, 74IX3964-8, 74IX3950, 9 ex., 81.2- 124.0 mm SL, Cao’e Jiang in Chenxian , Zhejiang . IHB 74 IX3502-4, 3 ex., 70.5 -79.5 mm SL, Ou Jiang in Jingyun , Zhejiang . IHB 74 IX4644, 74IX 4482-3, 74IX4485-9, 8 ex., 100.2- 166.5 mm SL, Ling Jiang in Xianju , Zhejiang . IHB 74 IX3285-6, 2 ex., 130.8-132.4 mm SL, Ling Jiang in Tiantai , Zhejiang . IHB 90 IV1635-6, 90IV1632, 3 ex., 98.4-127.2 mm SL, Xin Jiang in Guangfeng , Jiangxi . IHB 90 IV0192-3, 90IV0197, 90IV0201, 90IV0204, 5 ex., 94.4- 129.8 mm SL, Xin Jiang in Yujiang , Jiangxi . IHB 90 IV0658-9, 2 ex., 102.6-107.2 mm SL, Xin Jiang in Guiqi Jiangxi . IHB 90 IV0776-8, 3 ex., 112.7-125.6 mm SL, Xin Jiang in Yiyang , Jiangxi . IHB 8840938 , 8840940-4 , 5 ex.,102.6 -140. 6 mm SL, Yuan Jiang in Tongren , Guizhou . IHB 89 VII2089-90, 593885, 593742, 593735, 5 ex., 119.7 -166.0 mm SL, Yuan Jiang in Yuanling , Hunan . IHB 89 VII337-8, 89VII2335, 3 ex., 94.1-105.2 mm SL, Yuan Jiang in Luxi , Hunan . IHB 8840232-3 , 8840235 , 3 ex., 95.6-118. 7 mm SL, Yuan Jiang in Mayang , Hunan . IHB 8840007-9 , 8840015 , 8840013 , 5 ex., 86.0- 102.7 mm SL, Yuan Jiang in Jishou , Hunan . IHB 800754 , 1 ex., 54.5 mm SL, Wu Jiang in Sinan , Guizhou . IHB 0209001 , 0209005-6 , 0209009 , 0209012- 7 , 0209019 , 0209021-2 , 0209025 , 14 ex., 103.5- 124.6 mm SL, Xin’an Jiang in Tunxi , Anhui .

Sinibrama macrops : uncatalogued, 3 ex., 104.6 -144.4 mm SL, Taiwan. IHB 73 IV2025, 73X2151, 74 XII1445-7, 754961, 81X0581, 81XI4732-5, 11 ex., 89.2 - 160.2 mm SL, Pearl River in Rong’an , Guangxi. IHB 87 V881-2 , 87 V871-9 , 11 ex., 108.5-130.9 mm SL, Pearl River in Yongjiang , Guizhou. IHB 83 V0583 , 1 ex., 121.3 mm SL, Pearl River in Rongshui, Guangxi .

Figures

Fig. 2. Sinibrama longianalis, holotype, IHB 6650583, 134.3 mm SL; China: Guizhou: Zunyi, Lateral view.

Fig. 3. Map showing the distribution of the Chinese Sinibrama species.

Fig. 4. Three-dimensional distribution of the numbers of lateral line scales, scale rows above lateral line and branched rays in the anal fin of three species in Sinibrama. S. longianalis (Δ); S. macrops (D); S. wui (O).

Fig. 5. Scatterplots on scores of the first and second principal component for all specimens of three species in Sinibrama: S. longianalis (Δ); S. macrops (·); S. wui (O). Arrow indicating the specimens from Taiwan.