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This study describes the reproductive strategy of the sharpbelly Hemiculter leucisculus, an invasive and dominant species in Erhai Lake in China with the goal of understanding how reproductive strategy contributes to its environmental adaptability and invasive potential. Specimens (n = 3583) were collected monthly or bimonthly from July 2009 to June 2011 (min: 114-Feb, max: 883-Aug), using gill nets (inner/outer mesh = 30/110 mm, stretched mesh). Gonads were removed, weighed and preserved for further (histological) analyses. Oocyte size-frequency distribution was continuous and had advanced vitellogenic oocytes with postovulatory follicles present in spawning females, both suggesting that sharpbelly is a multiple spawner with adhesive eggs. Spawning extended from April to September, with the peak period from May to August. Standard lengths ( SL, cm) at minimal observed maturity/L50/L99.9 values were 4.6/5.6/10.5 for females and 5.1/5.5/7.5 cm for males, respectively. Females were over-represented (P < 0.01) in SL-classes over 9 cm and males completely absent from the 13 to 19 cm SL-classes. Overall sex ratio was highly significantly (P < 0.01) biased towards females (♀ = 1518, ♂ = 685, ♀/♂ = 2.21), however this was reversed in the spawning stock (8.3-16 cm, ♀ = 58, ♂ = 142, ♂/♀ = 2.45, P < 0.01). Batch spawning, a long spawning period, high male investment in reproduction and adhesive eggs all represent local adaptations in reproductive strategy that, along with other environmental factors, contribute to the invasion success of sharpbelly in Erhai. [ABSTRACT FROM AUTHOR]

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 4.3-19.1 cm for females and 4.6-12.3 cm for males. Length-weight relationships for females and males were significantly different and described as W = 0.0076 SL3.2608 and W = 0.0084 SL3.1901, 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 1-2 years old with a maximum age of only 3 years; 93.14% of females were 1-3 years old, with a maximum age of 6 years. Second, females grew larger than males at any age. Third, instantaneous mortality rates were much higher for males (4.22 year−1) than for females (1.17 year−1). [ABSTRACT FROM AUTHOR]