南海鸢乌贼微型群肌肉和性腺组织能量积累及其分配

Energy accumulation of both somatic and reproductive tissues and the allocation to reproduction in the dwarf form individuals of Sthenoteuthis oualaniensis in the south China Sea

利用组织能量密度测定技术和残差指标分析方法,分析南海鸢乌贼微型群个体肌肉组织和性腺组织的能量积累及其分配规律的变化过程。结果显示:微型群个体的肌肉和性腺组织之间的能量密度存在显著性差异;除缠卵腺之外,其他组织的能量密度均随性腺发育变化显著。肌肉组织和性腺组织的组织能量积累均随性腺发育增加显著。同一性腺成熟度等级肌肉组织的相对组织能量积累较高,性腺组织的相对组织能量积累相对较低。雌性个体性腺组织相对组织能量积累随着性腺发育增长显著,雄性个体性腺组织相对组织能量积累在Ⅰ~Ⅴ期增长较快,在Ⅵ~Ⅶ期趋于稳定。肌肉和性腺组织在性腺发育后期的质量特征较发育前期均显著改善,并且肌肉组织能量积累-胴长残差与性腺组织能量积累-胴长残差呈显著的正相关关系,表明性腺发育过程中的肌肉组织与性腺组织之间不存在能量交流。研究表明,南海鸢乌贼微型群个体的生殖能量倾向于外源性投入,肌肉和性腺组织的组织能量密度、组织能量积累和相对组织能量积累存在雌雄差异性。

By the technology of tissue energy density determination combined with residuals analyses,the energy accumulation of somatic and reproductive tissues and the allocation to reproduction in the female and male individuals of dwarf form of Sthenoteuthis oualaniensis in the south China Sea were analyzed.The results showed that:there was a significant difference in the tissue energy density between somatic and reproductive organs;and with the exception of nidamental gland,other tissues showed significant variations in the tissue energy density with the progress of maturation.The tissue energy was accumulated significantly in both somatic and reproductive tissues during the sexual maturation.For a given maturity stage,the proportion of somatic tissue energy was consistently larger than that of reproductive tissues.The relative energy accumulation of reproductive tissues of females increased significantly with maturation,while that in males increased rapidly from maturity stagesⅠtoⅤfollowed by a non-significant variation at stagesⅥandⅦ.At the advanced maturity stages,individuals of the dwarf form of Sthenoteuthis oualaniensis showed a better condition in both somatic and reproductive tissues.Further,residuals analyses indicated that a positive correlation was found between the residuals of each somatic tissue energy accumulation regressed on the mantle length and the residuals of reproductive tissues(combined nidamental gland,oviducal complex and ovary in females,while in males combined spermatophoric complex and testis)energy accumulation on the mantle length,suggesting that there was no energy trade-off between somatic and reproductive tissues during the sexual maturation.In combination,these lines of evidence indicated that energy for reproduction in the dwarf form of S.oualaniensis in the south China Sea is mainly derived from food intake,and there are sex-specific variations in the tissue energy density,energy accumulation and relative energy accumulation of both somatic and reproductive tissues.