科研之友
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摘要
The sharpbelly Hemiculter leucisculus, an invasive species, has expanded its range throughout much of Asia and into the Middle East. However, little is known of its adaptive changes regarding life history traits such as age, growth and mortality that could possibly explain its success as an invasive species. A detailed study of the invasive sharpbelly was conducted based on 4539 samples collected from July 2009 to June 2011 in Erhai Lake, China. Standard length ranged from 4.3-19.1cm for females and 4.6-12.3cm for males. Length-weight relationships for females and males were significantly different and described as W=0.0076SL(3.2608) and W=0.0084SL(3.1901), respectively. Otoliths are ideal for age determination because of the single annulus formed each year. Based on marginal increment analysis, the total mean CV for age estimate between two readings was 3.55%. The von Bertalanffy growth curves computed by observed length-at-age data were expressed as L-t=25.6 (1 - e(-0.176 (t+1.347))) for females and L-t=16.4 (1 - e(-0.354 (t+0.819))) for males. According to the age, growth and mortality data, there are three possible reasons for H.leucisculus attaining such dominance within a short time in Erhai Lake. First, because of the simple age structure of this species: 97.58% of males were 1-2years old with a maximum age of only 3years; 93.14% of females were 1-3years old, with a maximum age of 6years. Second, females grew larger than males at any age. Third, instantaneous mortality rates were much higher for males (4.22year(-1)) than for females (1.17year(-1)).
- 出版日期2013-12
- 单位华中农业大学; 中国科学院
