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paco.garcia[at]ebd.csic.es

Heliocidaris erythrogramma

Publications filtered by: Heliocidaris erythrogramma

Risk-spreading by mating multiply is plausible and requires empirical attention
Garcia-Gonzalez, F., Yasui, Y. & Evans, J.P. 2015 Risk-spreading by mating multiply is plausible and requires empirical attention Proceedings of the Royal Society of London B, 282: 20150866
Mating portfolios: bet-hedging, sexual selection and female multiple mating
Garcia-Gonzalez, F., Yasui, Y. and Evans, J. P. 2015 Mating portfolios: bet-hedging, sexual selection and female multiple mating Proceedings of the Royal Society of London B, 282: 20141525
Abstract

Polyandry (female multiple mating) has profound evolutionary and ecological implications. Despite considerable work devoted to understanding why females mate multiply, we currently lack convincing empirical evidence to explain the adaptive value of polyandry. Here we provide a direct test of the controversial idea that bet-hedging functions as a risk-spreading strategy that yields multi-generational fitness benefits to polyandrous females. Unfortunately, testing this hypothesis is far from trivial, and the empirical comparison of the across-generations fitness payoffs of a polyandrous (bet hedger) versus a monandrous (non-bet hedger) strategy has never been accomplished because of numerous experimental constraints presented by most ‘model’ species. In the present study we take advantage of the extraordinary tractability and versatility of a marine broadcast spawning invertebrate to overcome these challenges. We are able to simulate multi-generational (geometric mean) fitness among individual females assigned simultaneously to a polyandrous and monandrous mating strategy. Our approaches, which separate and account for the effects of sexual selection and pure bet-hedging scenarios, reveal that bet-hedging, in addition to sexual selection, can enhance evolutionary fitness in multiply-mated females. In addition to offering a tractable experimental approach for addressing bet-hedging theory, our study provides key insights into the evolutionary ecology of sexual interactions.

Linking sperm length and velocity: the importance of intramale variation
Fitzpatrick, J. L., Garcia-Gonzalez, F. & Evans, J. P. 2010 Linking sperm length and velocity: the importance of intramale variation Biology Letters, 6: 797-799
Abstract
Selection imposed through sperm competition is commonly thought to promote the evolution of longer sperm, since sperm length is assumed to be positively associated with sperm swimming velocity. Yet, the basis for this assumption remains controversial, and there is surprisingly little intraspecific evidence demonstrating such a link between sperm form and function. Here, we show that sperm length and velocity are highly correlated in the sea urchin Heliocidaris erythrogramma, but importantly we report that failure to account for within-male variation in these sperm traits can obscure this relationship. These findings, in conjunction with the mounting evidence for extremely high levels of intraspecific variance in sperm traits, suggest that a functional link between sperm morphology and velocity may be more prevalent than what current evidence suggests. Our findings also suggest that selection for faster swimming sperm may promote the evolution of longer sperm, thereby supporting recent findings from macroevolutionary studies.
Characterization of microsatellite loci for the Australian sea urchin Heliocidaris erythrogramma
Binks, R. M., Lukehurst, S. S., Garcia-Gonzalez, F. & Evans, J. P. 2009 Characterization of microsatellite loci for the Australian sea urchin Heliocidaris erythrogramma Molecular Ecology Resources, 9: 1259-1261
Abstract
We report 16 polymorphic microsatellite loci from Heliocidaris erythrogramma, a common sea urchin endemic to temperate Australian waters. These microsatellites were tested in a minimum of 30 individuals, which yielded between five and 14 alleles per locus. Expected heterozygosity ranged from 0.52 to 0.92 with four loci deviating from Hardy–Weinberg expectations. These markers are expected to be useful for experimental studies involving paternity analysis and for quantifying population structure in H. erythrogramma across its geographic range.
Sources of genetic and phenotypic variance in sperm performance and larval traits in a sea urchin
Evans, J. P., Garcia-Gonzalez, F. & Marshall, D. J. 2007 Sources of genetic and phenotypic variance in sperm performance and larval traits in a sea urchin Evolution, 61: 2832-2838
Abstract
In nonresource based mating systems females are thought to derive indirect genetic benefits by mating with high-quality males. Such benefits can be due either to the intrinsic genetic quality of sires or to beneficial interactions between maternal and paternal haplotypes. Animals with external fertilization and no parental care offer unrivaled opportunities to address these hypotheses. With these systems, cross-classified breeding designs and in vitro fertilization can be used to disentangle sources of genetic and environmental variance in offspring fitness. Here, we employ these approaches in the Australian sea urchin Heliocidaris erythrogramma and explore how sire–dam identities influence fertilization rates, embryo viability (survival to hatching), and metamorphosis, as well as the interrelationships between these potential fitness traits. We show that fertilization is influenced by a combination of strong maternal effects and intrinsic male effects. Our subsequent analysis of embryo viability, however, revealed a highly significant interaction between parental genotypes, indicating that partial incompatibilities can severely limit offspring survival at this life-history stage. Importantly, we detected no significant relationship between fertilization rates and embryo viability. This finding suggests that fertilization rates should not be inferred from hatching rates, which is commonly practiced in species in which it is not possible to estimate fertilization at conception. Finally, we detected significant additive genetic variance due to sires in rates of juvenile metamorphosis, and a positive correlation between fertilization rates and metamorphosis. This latter finding indicates that the performance of a male’s ejaculate in noncompetitive IVF trials predicts heritable offspring traits, although the fitness implications of variance in rates of spontaneous juvenile metamorphosis have yet to be determined.