阿根廷滑柔鱼雌性个体肌肉和性腺组织能量积累及其生殖投入

Energy accumulation of both somatic and reproductive tissues and its allocation to reproduction in Argentinean short-fin squid(Illex argentinus)

利用组织能量密度测定技术和残差指标分析方法,分析了阿根廷滑柔鱼雌性个体肌肉组织和性腺组织的能量积累及其分配规律。结果显示,足腕、胴体、卵巢、缠卵腺和输卵管复合体等组织的能量密度平均值分别为(22.75±0.60)、(23.42±0.68)、(25.15±2.08)、(21.49±1.46)和(25.12±3.02)k J/g。不同性腺成熟度等级,足腕、胴体和缠卵腺等组织的能量密度均不存在显著性差异,卵巢和输卵管复合体等组织的能量密度则差异显著。足腕、胴体等肌肉组织能量在性腺成熟度III期时达到最大值,卵巢、缠卵腺和输卵管复合体等性腺组织在I^III期时的能量积累缓慢,随后能量积累增长迅速,在生理性成熟后期(V期)或功能性成熟期(VI期)时达到最大值。随着性腺生长发育,肌肉组织能量占比逐渐下降,性腺组织能量占比逐渐增加。在性腺成熟度III^V期时,雌性个体肌肉组织能量部分转化用于性腺组织的生长发育,但这种生殖投入方式不影响肌肉组织的完整性。研究表明,阿根廷滑柔鱼生殖投入以外源性为主,但发育过程中肌肉组织存储能量部分转化以满足性腺发育对能量的需求。

The energy sourcing for reproduction in short-life cephalopod species is vitally important for the successful development of reproductive organs,in which the energy acquisition and allocation to gamete production would be greatly in relation to their reproductive strategies. Therefore,by using the technology of energy density determination combined with residuals analysis,we investigated the energy accumulation and allocation in both soma and reproductive organs of Argentinean short-fin squid Illex argentinus,an important cephalopod species,to provide further evidence whether the reproductive investment comes from food intake or diverts from the somatic growth. The tissue energy density was determined for the arms,mantle,ovary,nidamental gland and oviducal complex,where it had an average value of（22.75±0.60）,（23.42±0.68）,（25.15±2.08）,（21.49±1.46） and（25.12±3.02） k J/g,separately. There was no statistically significant difference in the energy density between different sexual maturity stages for the tissue of arms,mantle,and nidamental glands separately.However,the energy density was significantly different between sexual maturity stages for ovary and oviducal complex separately. Both arms and mantle attained their maximum tissue energy at maturity stage III. In the reproductive system,ovary attained its maximum tissue energy at maturity stage V,whereas both the tissue energy of nidamental gland and oviducal complex were gently increasing with maturity and attained their maximum value at maturity stage VI. Specifically,the tissue energy of oviducal complex had a burst increase after maturity stage IV onwards. At the same maturity stage,the somatic tissue energy,calculated as the sum of mantle and arms tissue energy,was always in the larger proportion,while the tissue energy of reproductive organs,calculated as the sum of tissue energy of ovary,nidamental gland and oviducal compex,accounted for a smaller percentage. However,the proportion occupied by somatic tissue energy was decreasing gradually,while that by reproductive organ was increasing with maturation. The soma energy was partly remobilized for reproduction from maturity stages III to V,but this process of remobilization did not impact the integrity of somatic tissues. These findings confirm that the reproductive investment in I. argentinus is mainly from food intake,but along with some energy remobilization from soma during the sexual maturation.