Growth, Diet Composition and Reproductive Biology of the Invasive Freshwater Fish Chevron snakehead Channa striata on...

Kuan-chung Li, Bao-sen Shieh, Yuh-wen Chiu, Da-ji Huang, and Shih-hsiung Liang (2016) The Chevron snakehead (Channa striata) has been invading Taiwan for over 30 years, and it is currently widely distributed across diverse aquatic habitats within the island. Due to its strong environmental adaptability and carnivorous diet, C. striata has caused great negative impacts to the biodiversity of native fishes and aquatic organisms in Taiwan. To effectively restrain its spatial distribution and population, the objective of this study was to investigate the growing conditions, diet composition, and reproductive biology of C. striata in the field. In total, 294 individuals were collected from wetlands, irrigation canals, streams, and reservoirs in southern Taiwan from September 2008 to December 2010. Among 272 sex-identified individuals, more females (164) were collected than males (108). The morphological differences between the sexes could not be distinguished by the 10 body measurements recorded. Diverse food items, including snails, odonates, fishes, amphibians, and reptiles, were identified in the stomachs of 35 individuals. The minimum body length of sexually mature C. striata females exhibited at a standard length of 24.5 cm (total length 28 cm). The appearance of mature oocytes were mainly observed from July to November in 2009 and from April to October in 2010. Greater absolute fecundity (oocyte/individual) was estimated in Taiwan for C. striata than in its original distribution range possibly due to less water level fluctuation in the sampling habitats of Taiwan. The relative fecundity (oocyte/g) for C. striata was considered lower but within the documented range in Taiwan when compared with its original habitat in Malaysia. To effectively manage C. striata in Taiwan, regionally eradiating young and adult individuals, especially during the reproductive season and educating people to stop releasing it in the wild are possible ways to restrain and control the further spread of this exotic fish in Taiwan.