...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Progress in Oceanography >Life history strategies in zooplankton communities: The significance of female gonad morphology and maturation types for the reproductive biology of marine calanoid copepods
【24h】

Life history strategies in zooplankton communities: The significance of female gonad morphology and maturation types for the reproductive biology of marine calanoid copepods

机译：浮游动物群落的生活史策略：女性性腺形态和成熟类型对海洋类cal足类足类生殖生物学的意义

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The present review addresses the reproductive strategies of marine calanoid copepods, as affected by their physiological preconditioning, and aims to enhance understanding of their adaptations to specific environmental conditions.rnKnowledge about oocyte development and internal gonad structure, especially in relation to feeding conditions, is essential for a complete understanding of the reproductive strategies of the copepods. Therefore, the foci of the review are to identify general patterns in oocyte and gonad development in calanoid copepod species from marine ecosystems worldwide and to elucidate the significance of gonad structures for reproductive strategies.rnOogenesis is similar in all copepod species. During maturation, the morphology of the oocytes changes distinctly and, according to oocyte size and appearance of ooplasm and nucleus, five oocyte developmental stages are distinguished. In contrast, the gonad structure and its changes during the spawning cycle differ considerably among species, and these differences are related to specific reproductive traits.rnFour gonad morphology types can be distinguished: the Calanus-type, found in species from all over the world with distinctly different life history traits, is apparently most common in calanoid copepods. In this gonad type, most oocyte developmental stages are present simultaneously, and usually many oocytes mature synchronously, all of which are released in one clutch. The gonad structure allows frequent spawning and large clutches, hence, high egg production rates. This may be a preconditioning for exploiting seasonally high food supply. However, the Calanus-type was also found in species producing eggs at lower rates. In the diverticula of Pseudocalanus-type gonads, only two oocyte developmental stages are present and usually fewer oocytes mature synchronously. Accordingly, the egg production rate is generally lower as compared to the Calanus-type, and apparently only this gonad-type is structurally suitable for ovigerity. Species with Pseudocalanus-type gonads are present from polar seas to the tropics, some of them being key species. The Acartia-type was scarce, found in only one species, Acartia clausi. Here all oocyte developmental stages are present, including intermediate stages, but only a few oocytes mature synchronously and are released together. High spawning frequency compensates for the small clutches, and hence egg production rate may be as high as in Calanus-type gonads. In the Aetidius-type gonad, the total number of oocytes in the diverticula is low as is the number of oocytes maturing synchronously. Less is known about the reproductive biology of species with Aetidius-type gonads; however, their distribution and feeding patterns suggest that this type is common in species inhabiting environments of low food availability.
机译：本综述针对受其生理预处理影响的海洋cal类co足类的繁殖策略，旨在增进对它们对特定环境条件的适应性的了解.n了解卵母细胞发育和内部性腺结构，尤其是与摄食条件有关的知识至关重要完整了解the足类的繁殖策略。因此，本综述的重点是确定全世界海洋生态系统中cal类co足类物种的卵母细胞和性腺发育的一般模式，并阐明生殖腺结构对生殖策略的重要性。在所有co足类物种中产卵相似。在成熟过程中，卵母细胞的形态发生明显变化，并且根据卵母细胞的大小以及卵质和细胞核的外观，可以区分出卵母细胞的五个发育阶段。相比之下，物种之间的性腺结构及其变化在产卵周期中有很大差异，这些差异与特定的生殖性状有关.rn可以区分四种性腺形态类型：在世界各地的物种中发现的Calanus型明显不同的生活史特征，显然最常见于cal足类。在这种性腺类型中，大多数卵母细胞发育阶段同时存在，通常许多卵母细胞同步成熟，所有卵母细胞都在一个离合器中释放。性腺结构允许频繁产卵和大型离合，因此，产蛋率高。这可能是开发季节性高食物供应的前提条件。但是，在以较低比率产卵的物种中也发现了Calanus型。在伪尾型性腺的憩室中，仅存在两个卵母细胞发育阶段，通常较少的卵母细胞同步成熟。因此，与Calanus型相比，产蛋率通常较低，并且显然只有这种性腺型在结构上适合于卵。从极地海域到热带地区都存在带有假性腺类性腺的物种，其中一些是关键物种。 A螨类型很稀少，仅在一种物种中被发现。这里存在所有卵母细胞发育阶段，包括中间阶段，但是只有少数卵母细胞同步成熟并一起释放。较高的产卵频率补偿了小的离合器，因此产蛋率可能与Calanus型性腺一样高。在Aetidius型性腺中，憩室中的卵母细胞总数很低，同步成熟的卵母细胞数量也很低。对带有Aetidius型性腺的物种的生殖生物学知之甚少。但是，它们的分布和喂养方式表明，这种类型在食物供应不足的物种栖息环境中很常见。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号