Maternal effects in marine decapod crustaceans

许多无脊椎动物的母亲表现出的行为被认为能提高后代的存活率，这种行为被统称为母性效应。母亲可能会产下更大的蛋，在单个蛋上投入更多的能量，在不同的时间产卵，孵化蛋，保护孵化的雏鸟免受捕食者的伤害，甚至用营养（护士）蛋喂养新孵化的后代。虽然其中一些行为显然是适应性的（例如，照顾幼雏和哺育卵），但其他行为（例如，卵的大小和产卵时间）对提高后代存活率的价值仍然存在争议，并且可能因物种而异。拟议的研究计划将探索三种海洋十足甲壳类动物的母性影响。选择这三个物种不仅是因为它们的经济和生态重要性，而且还因为它们的生活史和生态特征的对比。值得注意的是，雪蟹和美洲龙虾的幼虫分散阶段分别较长（数月）和较短（数周），而雕刻虾则延长了母性照顾的时间，孵化的幼崽一直待在雌性身上，直到幼年阶段。构成本研究计划的实验室和实地研究将更具体地关注母虾-后代的大小关系，产卵和孵化的时间，因为它们与母亲的大小和年龄有关，以及雕刻虾有营养卵的有趣可能性。该研究将评估较大的卵，早期和晚期孵化的好处，以及营养蛋对后代的生长和生存的好处。本研究对建立十足甲壳类动物生殖策略的多样性具有基本价值；它还在提供对适当管理加拿大一些最重要的渔业资源很重要的资料方面发挥了价值。

Mothers of many invertebrate species exhibit behaviours that are thought to improve the survival of their offspring and that are collectively called maternal effects. Mothers may make bigger eggs, invest more energy in individual eggs, oviposit at different times, incubate their eggs, protect the hatchlings from predators, or even feed the newly hatched offspring with trophic (nurse) eggs. While some of these behaviours are clearly adaptive (e.g., hatchling care and nurse eggs), the value of others (e.g., egg size and oviposition time) for increasing offspring survival is still open to debate and may differ among species. The proposed research program will explore maternal effects in three marine decapod crustaceans. The three species were selected for their economic and ecological importance, but also for their contrasting life-history and ecological features. Notably, the snow crab and American lobster have larval dispersal phases that are respectively long (months) and short (weeks), while the sculptured shrimp has extended maternal care with hatchlings remaining on females until the juvenile stage. The laboratory and field studies that constitute this research program will focus more specifically on the maternal-offspring size relationship, on the timing of oviposition and hatching as they relate to mother's size and age, and on the intriguing possibility that the sculptured shrimp has trophic eggs. The research will assess the benefits of larger eggs, of early versus late hatching, and of trophic eggs on the growth and survival of offspring. This research has basic value in contributing to establish the diversity of reproductive strategies among decapod crustaceans; it also applied value in providing information that is important for the proper management of some of Canada's most important fishery resources.