Population dynamics and frequency distribution of the nematode Procamallanas fulvidraconis and trematode Genarchopsis goppo in yellow-head catfish Pelteobagrus fulvidraco in Liangzi Lake of Hubei Province, China
Helminths in the stomach of the yellowhead catfish Pelteobagrus fulvidraco (Richardson) in the Liangzi lake of Hubei Province were investigated from February 2001 to July 2002. Three nematode species Procamallanus fulvidraconis, Camallanus cotti, Spinitectus gigi and a trematode Genarchopsis goppo were found. The latter two nematode species, with very low infection level, were not included in the further analysis as follows. Frequency distribution of P. fulvidraconis and the seasonal changes and frequency distribution of G. goppo were analyzed. Prevalence, mean abundance (+/-SD) and variance to mean ratio of P. fulvidraconis were 96.70%, 21.59 +/- 23.37 and 25.29, respectively. Its frequency distribution could not be described by the negative binomial model. There were positive correlations between abundance of P. fulvidraconis and the fish age and length (R-x,R-y = 0.3038, p < 0.001; R-x,R-y = 0.3938, p < 0.001), and convex curve of fish age-parasite was not detected. Prevalence, mean abundance (+/-SD) and variance to mean ratio of G. goppo were 48.61%, 2.45 +/- 5.44 and 12.09, respectively. Its frequency distribution fitted well with the negative binomial model. Abundance of G. goppo was also significantly correlated with fish age and length (R-x,R-y = 0.1694, p < 0.001; R-x,R-y = 0.2449, p < 0.001 but a peaked age-parasite curve was detected, concomitant with decrease of aggregation degree. Peaks of infection of G. goppo were observed in spring, late autumn and early winter, and significant difference of prevalence and mean abundance among months was found (G = 93.4 > chi(2)(0.05) = 27.58; F = 16.7, p < 0.001) The pattern of life history may be the cause of the seasonal changes of the parasite. Relationship between the yellowhead catfish and the two parasites was also discussed in the study.
Li Wen-Xiang (firstname.lastname@example.org) ; Wang Gui-Tang (email@example.com) ; Wu Shan-Gong; Yao Wei-Jian; Nie Pin.Population dynamics and frequency distribution of the nematode Procamallanas fulvidraconis and trematode Genarchopsis goppo in yellow-head catfish Pelteobagrus fulvidraco in Liangzi Lake of Hubei Province, China,Acta Hydrobiologica Sinica,2008,32(2):195-200