Reproduction, growth and diet of Gambusia holbrooki (Girard) in a temperate Australian river
Reproduction, growth and diet of Gambusia holbrooki (Girard) in a temperate Australian river
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DOI：
10.1002/aqc.3270010205
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发表时间：
1991-12
影响因子：
2.4
通讯作者：
L. Pen;I. Potter
中科院分区：
文献类型：
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作者：
L. Pen;I. Potter
1.在澳大利亚西南部的牧羊犬中，Gambusiaholbrooki的生物学描述使用从围网样品中获得的数据，在4-6周的时间间隔超过两年。2.在河中越冬的雌性在10月至2月之间繁殖（春季繁殖组），然后死亡。由此产生的雄性和雌性群体中的一些大型代表在1月至3月期间繁殖（夏季繁殖组），然后也死亡。这些较大的个体和较小的鱼的后代直到第二年春天才开始繁殖，那时它们构成了下一个繁殖季节的春季繁殖群体。当温度高于15-16°C，日长超过750-780分钟时，就会发生繁殖。春季怀孕雌性的平均长度从10月的33毫米增加到1月的52毫米，平均繁殖力从33增加到131。3.在牧羊犬河，G.霍尔布鲁克是一种多面手的食肉动物，在水面和整个水柱中进食。消化道内容物的大小范围很广。每个季节的holbrooki都没有在该系统中发现的三种本地鱼类的卵，幼虫，幼鱼或成年鱼。此外，没有证据表明G. Holbrooki对这些本地鱼类表现出竞争行为，例如剪鳍。4. 3种土著种与G.不同的产卵时间和地点有利于霍尔布鲁克鱼类的繁殖，从而有利于它们的养护。因此，土著物种的早期生活史阶段，这是最容易被捕食，通常产生在支流小溪或洪水沃茨之间的冬末和春末，一段时间之前的G繁殖。霍尔布鲁克河导致这种外来物种在夏季的主要河道中数量激增。
1. The biology of Gambusia holbrooki in the Collie River in southwestern Australia is described using data obtained from seine samples collected at 4–6 weekly intervals over two years. 2. Females which had overwintered in the river bred between October and February (spring-breeding group) and then died. Some of the large representatives of the resultant cohort of males and females bred between January and March (summer-breeding group) and then also died. The offspring of these larger individuals and the smaller fish did not start breeding until the following spring, when they constituted the spring-breeding group of the following breeding season. Breeding occurred when temperatures were above 15–16°C and day length exceeded 750–780 min. The increase in the mean length of the spring group of pregnant females from 33 mm in October to 52 mm in January was accompanied by a rise in mean fecundity from 33 to 131. 3. In the Collie River, G. holbrooki is a generalist carnivore, feeding at the water surface and throughout the water column. Gut contents of a wide size range of G. holbrooki from each season contained neither the eggs, larvae, juveniles nor adults of any of the three indigenous fish species found in the system. Moreover, there was no evidence that G. holbrooki exhibited agonistic behaviour, such as fin clipping, towards these native fish. 4. Coexistence of the three indigenous species with G. holbrooki, and thereby their conservation, is facilitated by the outcome of different spawning times and localities. Thus, the early life-history stages of the indigenous species, which are most susceptible to predation, are typically produced in tributary creeks or flood waters between late winter and late spring, some time before the breeding of G. holbrooki results in a population explosion of this exotic species in the main channel of the river during summer.