为了解拒马河鱼类时空分布及影响因子,基于2019—2021在拒马河的6次季节性鱼类调查,分析了拒马河鱼类群落结构及其与环境因子的关系。结果显示:共采集37种鱼类,隶属5目11科,鲤形目最多,占总种数的64.86%。相对重要指数(Index of relativ...为了解拒马河鱼类时空分布及影响因子,基于2019—2021在拒马河的6次季节性鱼类调查,分析了拒马河鱼类群落结构及其与环境因子的关系。结果显示:共采集37种鱼类,隶属5目11科,鲤形目最多,占总种数的64.86%。相对重要指数(Index of relative importance,IRI>)显示,IRI>≥500的优势种鱼类有10种,以鲫Carassius auratus Linnaeus、麦穗鱼Pseudorasbora parva Temminck&Schlegel、黑鳍鳈Sarcochilichthys nigripinnis Günther和宽鳍鱲Zacco platypus Temminck&Schlegel为主。单因素方差分析(ANOVA)表明,春、夏、秋季鱼类群落的个体数(N)、物种数(S)、Shannon-Wiener多样性指数(H’)和Margalef丰富度指数(DMa)存在显著差异,Pielou均匀度指数(J’)无显著差异。SNK多重比较检验(Student-Newman-Keuls)显示个体数、种类数以2019年5月(春季)最多,Shannon-Wiener多样性指数、Margalef丰富度指数以2019年8月(夏季)最高。等级聚类分析(Cluster)和非参数多变量排序(NMDS)分析显示,拒马河鱼类群落在空间上分为3组,上游S1拒马河源头和S2刁江汇为组Ⅰ,中游S3紫荆关大桥和S4清凉涧为组Ⅱ,中下游自S5小丰口桥至S15龙安大桥为组Ⅲ。丰度生物量比较曲线(ABC曲线)分析显示,2020年夏季鱼类群落结构稳定未受干扰(W=0.064),其余月份均受中度干扰(W<-0.007)。冗余分析(RDA)显示,海拔、水温和pH为影响拒马河鱼类群落结构时空变化的主要环境因子。研究可为拒马河鱼类资源保护和生态修复提供依据。展开更多
Two new species of the genus Cobitis from southern China,C.hereromacula from the Luohe River in Guangdong Province and C.baishagensis from the Nandujiang River in Hainan Province,are described and illustrated here.C.h...Two new species of the genus Cobitis from southern China,C.hereromacula from the Luohe River in Guangdong Province and C.baishagensis from the Nandujiang River in Hainan Province,are described and illustrated here.C.hereromacula can be distinguished from its congeners by possessing the following combination of characteristics;absence of the second and third pigmentary zones of Gambetta;13–16 oval blotches on the dorsum and 10–13 vertical,elongated triangular blotches below the midlateral line with more than 20 vertical dark brown bars between them;6–7 narrow rows of dark spots on the caudal fin;a vertical oval spot smaller than the eye diameter on the upper part of the caudal peduncle;pointed mental lobes of the lower lip pointed with a slightly filiform tip;one slender and long needle-shaped lamina circularis at the base of the first branched ray of the male pectoral fins.C.baishagensis can be distinguished from its congeners by the fourth Gambetta zone being covered by 10–12 transverse elongated blotches;4–5 narrow rows of dark spots on the caudal fin;a vertical blotch smaller than the eye diameter on the upper part of the caudal peduncle;males with a slender and long needle-shaped lamina circularis at the second branched pectoral fin ray in males;large scales with a slightly large focal zone;undeveloped mental lobes with a lower lip that does not end posteriorly in a filiform tip.展开更多
A new record of Pagrus caeruleostictus(Valenciennes,1830),collected from the Beibu Gulf,South China Sea in April 2013,was documented based on morphology and cytochrome oxidase I subunit(COI) gene barcoding analyses. I...A new record of Pagrus caeruleostictus(Valenciennes,1830),collected from the Beibu Gulf,South China Sea in April 2013,was documented based on morphology and cytochrome oxidase I subunit(COI) gene barcoding analyses. It can be distinguished by a combination of the following characteristics: head scaled to above eyes; cheeks with 5 or 6 rows of scales; lateral line scales 51–52; 5 rows of scales above the lateral line; 4 and 6 cuspidate teeth in front of upper and lower jaws,respectively,followed by 2 rows of blunter teeth posteriorly; gill rakers on first arch 12 to 15; D XI–XII +9–11; A III +8–9; the first two dorsal spines very short,the third to fifth extended,filamentous in the young; the first pelvic ray filamentous; silvery pink with dark blue spots on back and sides; caudal fin pinkish; other fins bluish or pinkish; the blue spots generally disappear in large specimens. The present report of P. caeruleostictus suggests that its distribution in Chinese coastal waters may be attributed to human effort,since this species is unlikely to have expanded naturally from the eastern Atlantic to the South China Sea,with no other records from the Indian or Pacific Oceans. We recommend that a precautionary approach should be adopted for the management of P. caeruleostictus.展开更多
基金Supported by the National Natural Science Foundation of China(No.31372166)
文摘Two new species of the genus Cobitis from southern China,C.hereromacula from the Luohe River in Guangdong Province and C.baishagensis from the Nandujiang River in Hainan Province,are described and illustrated here.C.hereromacula can be distinguished from its congeners by possessing the following combination of characteristics;absence of the second and third pigmentary zones of Gambetta;13–16 oval blotches on the dorsum and 10–13 vertical,elongated triangular blotches below the midlateral line with more than 20 vertical dark brown bars between them;6–7 narrow rows of dark spots on the caudal fin;a vertical oval spot smaller than the eye diameter on the upper part of the caudal peduncle;pointed mental lobes of the lower lip pointed with a slightly filiform tip;one slender and long needle-shaped lamina circularis at the base of the first branched ray of the male pectoral fins.C.baishagensis can be distinguished from its congeners by the fourth Gambetta zone being covered by 10–12 transverse elongated blotches;4–5 narrow rows of dark spots on the caudal fin;a vertical blotch smaller than the eye diameter on the upper part of the caudal peduncle;males with a slender and long needle-shaped lamina circularis at the second branched pectoral fin ray in males;large scales with a slightly large focal zone;undeveloped mental lobes with a lower lip that does not end posteriorly in a filiform tip.
基金Supported by the National Natural Science Foundation of China(Nos.31172053,41276166,31372532,31372166)the Project for Outstanding Young Teachers in Higher Education of Guangdong,China(No.Yq2013093)
文摘A new record of Pagrus caeruleostictus(Valenciennes,1830),collected from the Beibu Gulf,South China Sea in April 2013,was documented based on morphology and cytochrome oxidase I subunit(COI) gene barcoding analyses. It can be distinguished by a combination of the following characteristics: head scaled to above eyes; cheeks with 5 or 6 rows of scales; lateral line scales 51–52; 5 rows of scales above the lateral line; 4 and 6 cuspidate teeth in front of upper and lower jaws,respectively,followed by 2 rows of blunter teeth posteriorly; gill rakers on first arch 12 to 15; D XI–XII +9–11; A III +8–9; the first two dorsal spines very short,the third to fifth extended,filamentous in the young; the first pelvic ray filamentous; silvery pink with dark blue spots on back and sides; caudal fin pinkish; other fins bluish or pinkish; the blue spots generally disappear in large specimens. The present report of P. caeruleostictus suggests that its distribution in Chinese coastal waters may be attributed to human effort,since this species is unlikely to have expanded naturally from the eastern Atlantic to the South China Sea,with no other records from the Indian or Pacific Oceans. We recommend that a precautionary approach should be adopted for the management of P. caeruleostictus.
