Age and size-dependent variation in the seasonal timing and probability of reproduction among mature female pumpkinseed,Lepomis gibbosus
Age and size-dependent variation in the seasonal timing and probability of reproduction among mature female pumpkinseed,Lepomis gibbosus
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成熟雌性南瓜籽 Lepomis gibbosus 季节时间和繁殖概率的年龄和大小依赖性变化
DOI：
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发表时间：
1994
影响因子：
1.4
通讯作者：
M. Fox
中科院分区：
文献类型：
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作者：
A. Danylchuk;M. Fox
在本研究中，我们使用南瓜籽，Lepomis gibbosus，两个安大略省中东部湖泊的种群来测试年龄和大小对成熟雌性繁殖概率和时间的影响。南瓜籽体大小特征在两个湖泊中存在差异；小圆湖有发育不良的人口，而比洛波林湖没有。通过对产卵前和产卵中期收集的鱼的成熟度评估，结合早期捕获-标记-再捕获调查，确定了成熟雌鱼的年龄等级分布。在整个繁殖季节收集产卵雌鱼，以评估其年龄和体型相关的时间趋势，并将其年龄和体型分布与整个成熟雌鱼的年龄和体型分布进行比较。小圆湖2龄雌鱼实际产卵的比例明显低于整个2龄雌鱼的比例。此外，在这个湖中产卵的2岁雌性直到繁殖季节后期才这样做。相比之下，幼雌/小雌在Beloporine湖产卵的比例与幼雌/小成熟雌的比例相当，并且在整个繁殖季节，幼雌和大雌都产卵。由于身体状况不佳，小圆湖的成年雌鱼可能别无选择，只能在季节后期产卵。在Beloporine湖，2 ~ 4岁雌鱼在繁殖季节早期的条件因子高于小圆湖雌鱼，这表明春季能量储备有限可能阻碍了小圆湖雌鱼早期产卵。我们的研究结果表明，在一些种群中，繁殖的可能性和时间取决于年龄和体型。推迟季节性成熟和在夏末产卵的小个体可能对种群的贡献很小，因为它们的生长受到限制，后代的越冬存活率降低。
SynopsisIn this study, we used pumpkinseed,Lepomis gibbosus, populations in two east-central Ontario lakes to test for age and size-dependent effects on the probability and timing of reproduction of mature females. Pumpkinseed body size characteristics differed in the two lakes; Little Round Lake harbours a stunted population and Beloporine Lake does not. Age-class distribution of mature females was determined by a maturity assessment on fish collected just prior to spawning and at the mid-spawning period, combined with an early-season capture-mark-recapture survey. Spawning females were collected throughout the breeding season to assess age and size-related temporal trends, and to compare their age and size distribution with that of mature females at large. The proportion of age 2 females in Little Round Lake that actually spawned was considerably lower than the proportion of mature age 2 females at large. Furthermore, age 2 females that spawned in this lake did not do so until late in the breeding season. In contrast, the proportion of young/small females spawning in Beloporine Lake was comparable to the proportion of young/small mature females at large, and both small and large females spawned throughout the breeding season. Small mature females in Little Round Lake may have had no other option but to spawn late in the season because of their poor body condition. In Beloporine Lake, condition factor early in the breeding season in age 2–4 females was higher than that of Little Round Lake females, suggesting that limited energy reserves in the spring may have prevented young Little Round Lake females from early spawning. Our results show that the likelihood and timing of reproduction are both age and size-dependent in some populations. Small individuals that delay seasonal maturation and spawn late in the summer probably contribute little to the population due to the restricted growth and reduced overwinter survival of their progeny.