The evolutionary puzzle of egg size, oxygenation and parental care in aquatic environments.

ABSTRACT: Offspring fitness generally improves with increasing egg size. Yet, eggs of most aquatic organisms are small. A common but largely untested assumption is that larger embryos require more oxygen than they can acquire through diffusion via the egg surface, constraining egg size evolution. However, we found no detrimental effects of large egg size on embryo growth and survival under hypoxic conditions. We tested this in the broad-nosed pipefish, Syngnathus typhle, whose males provide extensive care (nourishment, osmoregulation and oxygenation) to their young in a brood pouch on their bodies. We took advantage of this species' pronounced variation in egg size, correlating positively with female size, and tested the effect of hypoxia (40% dissolved oxygen) versus fully oxygenated (100%) water o

SUBMITTER: Braga Goncalves I 

PROVIDER: S-EPMC4632610 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature