头足类动物个体发生和生命周期模式

• ¹巴西联邦大学的巴拉那河
• ²美国特拉华州的自然历史博物馆

生命周期定义为概念化提供背景意义的问题解决机制,生成不同的生命周期模式。本文提供了明确的定义和解释的步骤在头足类动物的生命周期,从受精到死亡。每个大步骤或阶段,特点是一个特定的发育过程和形态。每个阶段由小发育不同的步骤,或阶段。cephalo-pod生命周期的全部或部分由以下阶段:胚胎,Paralarval,少年,亚成体,成人和衰老,taxon-specific每个生命周期。所有的头足类动物直接开发和维护一个一致的身体在个体发生(即计划。,没有真正的幼虫阶段,没有变形)。大多数头足类动物都有生命周期,一长一短早期生活和成年衰老紧随其后。头足类动物有两种发展模式:生产小型浮游paralarvae幼仔,或大型幼仔是青少年。所有的头足类动物都要经历一个人工孵化阶段羽化后不久就依赖于两种模式的营养:内生(蛋黄)和外源性(猎物)。许多头足类动物和浮游paralarvae将成为底栖生物在生命周期早期在结算阶段。 Juvenile growth is fast and ontogenetic changes (outside of gonadal maturation) generally cease at the end of the Juvenile phase. The Subadult phase begins when the definitive adult morphology (except for size and body proportions) is acquired (e.g., photophores). Sexual organs undergo most of their development during the Subadult phase. The Adult phase starts with spawning competency. The Senescent phase begins with spent gonads and ends with death. Using this new terminology, we examine the patterns of cephalopod life cycles and find that there are four main patterns based on the presence of a Paralarval phase and the habitat occupied by each phase: Holopelagic (all phases are pelagic), Holobenthic (all phases are benthic), Merobenthic and Meropelagic (phases alternate between benthic and pelagic environments). In these two last patterns, the main difference is the presence of a paralarval phase in Merobenthic species. The definitions and terminology proposed here provide a unifying framework for future ecological and evolutionary research on cephalopods.