- 期刊
Size Structure, Reproductive Phenology, and Sex Ratio of an Exotic Armored Catfish (Liposarcus multiradiatus) in the Kaoping River of Southern Taiwan
並列摘要
The sailfin catfish, Liposarcus multiradiatus (Hancock, 1828), was originally introduced into Taiwan commercially for aquarium cleaning, and has now established a wild population in Taiwan. This study investigates the size structure, reproductive phenology, and sex ratio of this exotic species in the Kaoping River of southwestern Taiwan. In total, 537 individuals were respectively collected using gill nets and cast nets in the mainstream and tributaries of the Kaoping River from Dec. 1999 to Nov. 2000. The standard lengths of collected individuals ranged from 12.5 to 43.7 cm, with an average of 28.64 cm. Females were longer than males. Variations in morphological differences between the sexes could not clearly be distinguished by the 13 body measurements. The female L. multiradiatus is sexually mature at a standard length of 25 cm, and has a reproductive season extending from Mar. to Sept. in Taiwan. Some individuals, however, are able to reproduce from Oct. to Feb. The sex ratio was female-biased (female: male, 2.4: 1), and an even greater proportion of females was found during the reproductive season. Results show that L. multiradiatus exhibits detritus/algae and omnivorous feeding habits, a long reproductive period, a female-biased sex ratio, and possible male parental care. Considering that the sailfin catfish originally inhabits clear, shallow waters, L. multiradiatus in Taiwan has not only expanded its population size in downstream regions but may also gradually move to clearer waters upstream or into smaller channels. This species may create serious negative impacts on those native aquatic species such as periphyton feeders and bottom spawners. It is suggested that educating people to stop releasing sailfin catfish and providing incentives for catching it in reproductive season are two possible ways to control the further spread of this exotic species in Taiwan.