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Vol. 53, 2014
Life history traits of the Chinese minnow Rhynchocypris oxycephalus in the upper branch of
Yangtze River, China
Yangyang
Liang1,2, Xiaoyun Sui1,3*, Yifeng Chen1,
Yintao Jia1 and Dekui He1
1Laboratory
of Biological Invasion and Adaptive Evolution, Institute of
Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road,
Wuchang District, Wuhan, Hubei Province 430072, China
2University of Chinese Academy of Sciences, No. 19A
Yuquan Road, Beijing 100049, China
3School of Life Sciences, Peking University, No. 5
Yiheyuan Road, Haidian District, Beijing 100871, China
Abstract
Background: Study of the life
history traits of any species plays an essential role for understanding
their relationship with the surrounding environment and scientific
management. The Chinese minnow Rhynchocypris
oxycephalus, an
ecologically and economically important species which was widely
distributed in East Asia, is currently diminishing. In the present
study, we depicted the main life history traits of R. oxycephalus for the first time.
Results: A total of 442 individuals were collected
from April 2012 to March 2013, with total length (TL) ranging from 32.2
to 158.0 mm. The otolith (lapillus) was proved suitable for age
determination. Moreover, the results from marginal increment ratio
(MIR) analyses demonstrated its unusual growth pattern: two pairs of
opaque and transparent bands were formed each year, which might provide
some implications for the age determination of other species. The
maximum age for females (4 years) was higher than for males (3 years),
while 1- and 2-year-old individuals dominated the population. Both
females and males reached maturity at 1 year, and the TL at first
maturity was 78.8 mm for females and 60.3 mm for males. Obvious sexual
dimorphism was observed as females growing faster and larger than males
after maturity. As a multiple spawner, R. oxycephalus releases batches of
eggs from April to August. The fecundity of R. oxycephalus was higher, and the
size of eggs was larger than that of its closely related species.
Conclusions: R. oxycephalus is a short-lived,
fast-growing, highly fecund, and early-maturing species; therefore,
even a short recovery time after overexploitation or disturbance would
be of great use for their restoration. Some life history traits of R. oxycephalus demonstrate obvious
differences with its closely related species, indicating that latitude
and local environment conditions are important selective forces for
this species.
Key words: Annuli; Otolith; Age
determination; Growth pattern; Reproduction.
*Correspondence: E-mail: xiaoyunsui@ihb.ac.cn
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