Sex differences in biochemical composition, energy content and allocation to reproductive effort in the brooding sea star Leptasterias polaris
Sex differences in biochemical composition, energy content and allocation to reproductive effort in the brooding sea star Leptasterias polaris
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育雏海星北极海星的生化成分、能量含量和生殖努力分配的性别差异
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
H. Guderley
中科院分区：
文献类型：
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作者：
J. Raymond;J. Himmelman;H. Guderley
通过检测产卵前、产卵后和孵化后3个不同时期的主要身体成分的生化组成和能量含量，评价了加拿大东部圣劳伦斯湾北部的北极星海星(Lepta-sterias Polaris)在繁殖投资方面的性别差异。水下质量为10g(相当于半径8.2厘米)的标准海星的繁殖力男女相似(雄性15.1kJ，雌性12.2kJ)。然而，两性在生殖能量的分配方式上存在差异。由于配子释放造成的能量损失，雄性(15.1kJ)几乎是雌性(4.1kJ)的4倍。雌性的主要生殖支出来自长时间孵化期间的维持费用(8.1kJ)。体壁和胃的脂肪、蛋白质和能量含量在产卵期和孵化期雄性和雌性相似。在较小的班级中，雌雄比例为1：1，但在半径为11厘米的个体中，男女比例约为2：1。这可能是由于雌性由于重复使用能量储备和在5至6个月的孵化期间缺乏食物而导致躯体生长缓慢的原因。雄性在冬季身体壁碳水化合物的补充(雌性没有观察到)表明雄性在这一时期进食。
We assessed sex differences in reproductive investment of the brooding sea star Lepta- sterias polaris (in the northern Gulf of St. Lawrence, eastern Canada) by examining the biochemical composition and energetic content of the principal body components in 3 contrasting periods: just before spawning, after spawning and after brooding. The reproductive effort for a standard sea star with an underwater mass of 10 g (equivalent to 8.2 cm in radius) was similar for both sexes (15.1 kJ in males and 12.2 kJ in females). However, the sexes differed in how energy was allocated for repro- duction. The energy loss due to gamete release was almost 4-fold greater for males (15.1 kJ) than females (4.1 kJ). The major reproductive expenditure in females came from maintenance costs dur- ing the prolonged brooding period (8.1 kJ). For the body wall and stomach, lipid, protein and energy contents were similar for males and females over the spawning and brooding periods. The ratio of males to females in the population was 1:1 in smaller size classes but was about 2:1 for individuals measuring >11 cm in radius. This is possibly explained by slower somatic growth of females due to the repeated use of energetic reserves and lack of feeding during the 5 to 6 mo brooding period. The replenishment of body wall carbohydrates in males during the winter (not observed in females) suggests that males feed during this period.