Ontogenetic variability of maternal effects in an iteroparous fish

Abstract

Maternal effects have been observed to interact with genotypic and environmental influences to structure offspring phenotypes across a wide variety of taxa. In fishes, maternal effects may be especially important due to their potential influence on development and survival during early ontogeny -a period with high potential for population regulation. While previous studies have confirmed that maternal effects on offspring phenotype are common in fishes, the consistency with which they positively affect offspring fitness throughout early ontogeny remains largely unknown. We examined maternal effects on offspring fitness by quantifying relationships between maternal (length, mass and age), egg (diameter, mass and density) and larval traits (length, yolk-sac volume and survival) in yellow perch (Perca flavescens). Consistent with several past studies, positive relationships among maternal and egg traits were evident. While egg mass was positively related to larval size at hatching, direct relationships between maternal and larval metrics were not apparent. Larval survival appeared to have two critical periods; in contrast with expectations, survival in the first 5 days posthatch was strongly negatively related to female size and age, while survival over the following 9 days was unrelated to maternal traits. Throughout the study, survival was positively related to yolk-sac volume. Our unexpected observation of a negative relationship between maternal size and age and initial larval survival indicates that maternal effects may not be consistent throughout larval ontogeny. In fact, maternal effects appear to be dynamic influences on offspring fitness, and may have complex effects on individual-and population-level reproductive success.

Fatty acids in an iteroparous fish: variable complexity, identity, and phenotypic correlates

“…In most fish species, larger eggs and larvae with increased lipid reserves are considered higher quality (Brooks et al 1997;Venturelli et al 2009;Fuiman and Ojanguren 2011;Olin et al 2012;Andree et al 2015). We observed positive correlations between fatty acid complexity of individual females and the quality eggs they produced, as determined by egg size, lipid content, and egg size variability, suggesting that females with more complex fatty acid profiles produced higher-quality eggs.…”

“…Egg size, and potentially egg size variation, have been shown to be an important predictor of larval size, growth, and survival (Bagenal 1969;Marsh 1986;Andree et al 2015). Therefore, the egg traits we measured (egg diameter, dry mass, lipid content, and diameter CV) likely provide some predictive power for the potential quality of offspring produced by each female.…”

“…These fish originated from broodstock captured in the Perquimans River, NC, USA, in 1992. This stock is held and allowed to spawn naturally in outdoor ponds each spring, with occasional supplementation via indoor spawning and hatching of larvae (Andree et al 2015;Feiner et al 2016a). Whole skeins were stripped from females as they became ready to spawn in the spring.…”

Maturation at a young age and small size of European smelt (Osmerus eperlanus): A consequence of population overexploitation or climate change?

“…Smaller and younger individuals produce offspring with similar genotypes that are characterized by early maturation and low absolute fecundity, as the latter depends on fish weight [41]. Older/larger fish, to the contrary, tend to spawn a higher number of eggs; thus, a shift to earlier maturation in a population reduces the survival potential of embryos and larvae and increases annual recruitment variability [42,43]. Considering this, it is likely that smelt population overfishing had a significant effect on observed rates of smelt early maturation.…”

“…data). Such a shift to earlier maturation in a population due to changed climatic conditions reduces the survival potential of embryos and larvae and increases the variability of annual recruitment [42,43]. This, in turn, makes the population vulnerable to external conditions and results in unstable smelt fishery with implications to the performance of fishery.…”