RESUMEN
A new cave-dwelling fish, Triplophysa anshuiensis, is described here based on specimens collected from a karst cave in Guangxi Zhuang Autonomous Region, China, interconnected with the Hongshui River system, a tributary of the Xijiang River in the Pearl River (Zhu Jiang) Drainage. The species can be distinguished from its congeners by a combination of morphological characters. A key to the cave-dwelling species of Triplophysa in the Xijiang River is provided.
RESUMEN
A new blind loach of the genus Triplophysa was collected in 2007 from a cave in Leyi village, located near Chuanshan Town, Huangjiang County in the Guangxi Zhuang Autonomous Region of southern China. The new species, Triplophysa huangjiangensis sp. nov, can be distinguished from its congeners by eyes and scales absent; caudal-fin forked; adipose keel present; lips with furrows; distal margin of dorsal-fin truncate, dorsal fin origin much closer to caudal-fin base than snout tip; 8-9 branched dorsal-fin rays; 6-7 branched pelvic-fin rays; 6 branched anal-fin rays; 10-11 branched pectoral-fin rays; 13-14 branched caudal-fin rays; pectoral-fin length 52.3%-70.7% the distance between pectoral-fin origin to pelvic-fin origin; dorsal-fin origin posterior to vertical line of pelvic-fin origin; outer rostral barbel longer than other two pairs of barbels, with 47.0%-73.8% of lateral head length; anterior nostril with elongate barbel-like tip; and posterior chamber of gas-bladder developed, reaching pelvic-fin origin.
Asunto(s)
Cipriniformes/clasificación , Animales , China , Cipriniformes/crecimiento & desarrolloRESUMEN
Morphological characteristics were compared between three recorded species of rounded caudal fin Oreonectes and specimens collected from Guan'an of Guangxi. The results showed the Oreonectes sp. from Guan'an was distinguished from O. anphthalmus. Although some morphologic differentiations existed among Oreonectes sp., O. polystigmus, and O. platycephalus, their differentiations were not enough to distinguish between them. Consequently, we used multivariate morphometrics to determine their morphologic differentiation. Twenty-six frame characteristics and 20 general characteristics of 63 specimens were measured. The results of the Principal Component Analysis showed that Oreonectes sp. and O. polystigmus, and Oreonectes sp. and O. platycephalus occupied obviously different areas in the scatter plot. It is suggested that the specimens collected from Guan'an may be a cryptic new species of Oreonectes. However, its taxonomic status should be decided by evidence from anatomical and molecular biological studies.
Asunto(s)
Aletas de Animales/anatomía & histología , Cipriniformes/clasificación , Animales , China , Cipriniformes/anatomía & histologíaRESUMEN
A new species, Sinocyclocheilus huangtianensis, is found from a cave of Hejiang River, Hezhou, Guangxi, China. This river is a tributary of the Pearl River. It is similar to S. jii, distributed in Hejiang and S. guilinensis distributed in Lijiang by having a soft dorsal spine without serration and normal eyes. The combination of the following characteristics makes this new species different to S. jii and S. guilinensis: (1) the lateral line scales 52-59, up lateral line scales 17-23, the down lateral line cales 16-17, the circumpeduncular scales 40-46; (2) gill raker 9-10; (3) eye diameter/SL 4.3-5.4%; (4) interorbital width /SL 9.2-9.6%; and (5) mouth width/SL 6.0-7.3%.
Asunto(s)
Cyprinidae/anatomía & histología , Cyprinidae/clasificación , Animales , China , Femenino , MasculinoRESUMEN
This study aims to develop a multi-metric, fish-based Index of Biological Integrity (IBI) for assessing the environmental quality of rivers in Hechi Prefecture, Guangxi Province, South China. Data on fish assemblage were collected via electrofishing We screened 21 candidate metrics representing attributes of fish assemblage. Among these, six metrics were finally selected for the IBI. It was shown that the fish-based biological integrity was good in Xiaohuanjiang River , fair in Hongshuihe, Longjiang and Dahuanjiang Rivers, but poor in Diaojiang River. The results of assessment were consistent with the actual situation of human disturbance. The assessment system constructed by this study could be used or used for reference in the area around Hechi. Biotic integrity assessment was an important means of water environment quality monitoring. To enable the biotic integrity assessment more scientific and more objective, much more research work is required to focus on the relationship between biotic integrity and environmental factors.