Maternal effects in marine decapod crustaceans

许多无脊椎动物物种的母亲表现出被认为可以提高后代存活率的行为，这些行为统称为母性效应。母亲可能会生更大的蛋，在单个蛋上投入更多的能量，在不同的时间排卵，孵化它们的蛋，保护孵化的幼崽不受捕食者的伤害，甚至用营养(哺育)的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，孵化和哺育卵)，但其他行为(例如，蛋的大小和产卵时间)对于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类甲壳类动物的母体效应。选择这三个物种是因为它们的经济和生态重要性，但也因为它们截然不同的生活史和生态特征。值得注意的是，雪蟹和美国龙虾的幼虫传播期分别长(几个月)和短(几周)，而雕刻的虾延长了母爱，孵化的幼体一直留在雌性身上，直到幼体阶段。组成这一研究计划的实验室和实地研究将更具体地关注母子大小关系，产卵和孵化的时间与母亲的大小和年龄有关，以及有趣的可能性，即雕刻的虾有营养卵。这项研究将评估较大的鸡蛋、早期孵化和后期孵化的好处，以及营养鸡蛋对后代生长和存活的好处。这项研究对于确定十足目甲壳类动物繁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十分重要的信息方面具有应用价值。

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.