In this study, the relationship of the growth of invasion fish with water eutrophication processes was explored in Yangtze estuary, China. High water ammonia nitrogen concentration produced high effects on the growth ...In this study, the relationship of the growth of invasion fish with water eutrophication processes was explored in Yangtze estuary, China. High water ammonia nitrogen concentration produced high effects on the growth and survival of mosquitofish Gambusia affinis. When the ammonia nitrogen was higher than 51.75 mg/l, the fish death rate obviously increased with days, and at the 4th day fish presented the highest mortality, while 23.72 mg/l ammonia nitrogen conditions have been able to ensure fish survival for two days in experiment treatment. Therefore, ammonia nitrogen of Grade V polluted water (national water quality criteria) is just 3 mg/l, and the water can be enough to support fish normal survival. Our results suggest mosquitofish was a suitable pioneer species for restoring polluted water ecology and purify water.展开更多
Investigation of the ecology of introduced species in new habitats can allow determinations of the degree, direction, and rate of evolutionary change. The introduction of Gambusia holbrooki in the southern Caspian Sea...Investigation of the ecology of introduced species in new habitats can allow determinations of the degree, direction, and rate of evolutionary change. The introduction of Gambusia holbrooki in the southern Caspian Sea presents such a situation. We evaluated the life history traits of mosquitofish in the Tajan River basin. A total of 744 G. holbrooki specimens were collected between January and December 2008. The maximum observed ages are 0+ years for males and 1+ years for females. Both sexes grew allometrically (negative for males: b=2.442 and positive for females: b=3.232). The overall sex ratio is unbalanced and dominated by females. GSI values suggest that this population of G. holbrooki matures between February–July. The highest mean GSI value is 1.80 for males and 15.97 for females in May. Egg diameter ranges from 1.00 to 3.00 mm with a mean value of 2.098 mm. Absolute fecundity varied from 7 to 57 eggs. Both ova diameter and absolute fecundity were positively correlated to fish size (length and weight). Fecundity relative to total weight fluctuated from 34.44 to 582.64 eggs/g, and to total length from 2.33 to 12.95 eggs/cm. Both were negatively correlated with female size. The characteristics of this population are important with respect to life history of the species.展开更多
食蚊鱼Gambusia affinis(Baird et Girard)属于鱂形目(Cyprinodontiformes)、胎鱂科(Poeciliidae)。是一种原产北美洲的热带性卵胎生小鱼。这种鱼自1927年从马尼拉引入我国后,已成为遍及我国南方淡水小鱼,并在灭蚊控疟方面发挥一定作用...食蚊鱼Gambusia affinis(Baird et Girard)属于鱂形目(Cyprinodontiformes)、胎鱂科(Poeciliidae)。是一种原产北美洲的热带性卵胎生小鱼。这种鱼自1927年从马尼拉引入我国后,已成为遍及我国南方淡水小鱼,并在灭蚊控疟方面发挥一定作用。有关其繁殖生物学Rosen,D.E.et al.(1963),Resenthal,H.L.(1952),Turner,C.L.(1937,1941.)曾有过报道,为了补充食蚊鱼繁殖生物学资料,作者在1979—1982年在广州对其生殖特性作了观察研究。展开更多
文摘In this study, the relationship of the growth of invasion fish with water eutrophication processes was explored in Yangtze estuary, China. High water ammonia nitrogen concentration produced high effects on the growth and survival of mosquitofish Gambusia affinis. When the ammonia nitrogen was higher than 51.75 mg/l, the fish death rate obviously increased with days, and at the 4th day fish presented the highest mortality, while 23.72 mg/l ammonia nitrogen conditions have been able to ensure fish survival for two days in experiment treatment. Therefore, ammonia nitrogen of Grade V polluted water (national water quality criteria) is just 3 mg/l, and the water can be enough to support fish normal survival. Our results suggest mosquitofish was a suitable pioneer species for restoring polluted water ecology and purify water.
文摘Investigation of the ecology of introduced species in new habitats can allow determinations of the degree, direction, and rate of evolutionary change. The introduction of Gambusia holbrooki in the southern Caspian Sea presents such a situation. We evaluated the life history traits of mosquitofish in the Tajan River basin. A total of 744 G. holbrooki specimens were collected between January and December 2008. The maximum observed ages are 0+ years for males and 1+ years for females. Both sexes grew allometrically (negative for males: b=2.442 and positive for females: b=3.232). The overall sex ratio is unbalanced and dominated by females. GSI values suggest that this population of G. holbrooki matures between February–July. The highest mean GSI value is 1.80 for males and 15.97 for females in May. Egg diameter ranges from 1.00 to 3.00 mm with a mean value of 2.098 mm. Absolute fecundity varied from 7 to 57 eggs. Both ova diameter and absolute fecundity were positively correlated to fish size (length and weight). Fecundity relative to total weight fluctuated from 34.44 to 582.64 eggs/g, and to total length from 2.33 to 12.95 eggs/cm. Both were negatively correlated with female size. The characteristics of this population are important with respect to life history of the species.
文摘食蚊鱼Gambusia affinis(Baird et Girard)属于鱂形目(Cyprinodontiformes)、胎鱂科(Poeciliidae)。是一种原产北美洲的热带性卵胎生小鱼。这种鱼自1927年从马尼拉引入我国后,已成为遍及我国南方淡水小鱼,并在灭蚊控疟方面发挥一定作用。有关其繁殖生物学Rosen,D.E.et al.(1963),Resenthal,H.L.(1952),Turner,C.L.(1937,1941.)曾有过报道,为了补充食蚊鱼繁殖生物学资料,作者在1979—1982年在广州对其生殖特性作了观察研究。
