The unexpected but understandable dynamics of mating, paternity and paternal care in the ocellated wrasse

Abstract

Although theory generally predicts that males should reduce paternal care in response to cues that predict increased sperm competition and decreased paternity, empirical patterns are equivocal. Some studies have found the predicted decrease in male care with increased sperm competition, while even more studies report no effect of paternity or sperm competition on male care. Here, we report the first example, to our knowledge, of paternal care increasing with the risk and intensity of sperm competition, in the ocellated wrasse (Symphodus ocellatus). Theory also predicts that if paternal care varies and is important to female fitness, female choice among males and male indicators traits of expected paternal care should evolve. Despite a non-random distribution of mating success among nests, we found no evidence for female choice among parental males. Finally, we document the highest published levels of extra-pair paternity for a species with exclusive and obligate male care: genetic paternity analyses revealed cuckoldry at 100 per cent of nests and 28 per cent of all offspring were not sired by the male caring for them. While not predicted by any existing theory, these unexpected reproductive patterns become understandable if we consider how male and female mating and parental care interact simultaneously in this and probably many other species.

Predictably Philandering Females Prompt Poor Paternal Provisioning

“…Our results warrant more research into these interacting effects between female and male behavior in a pair. Such interacting within-male effects between mating partners are likely to be frequent and have the power to challenge our traditional models about sexual conflict, mate choice, and parental care (Westneat and Stewart 2003;Alonzo 2010;Lehtonen and Kokko 2015) but have not often been investigated (Alonzo and Heckman 2009).…”

Too many men: the violence problem?

“…Equating mate competition with violence likely conceals more interesting patterns. Behavioral polymorphisms in male mating strategies abound in many species, including humans [92][93][94]. Models show that, in male-biased ASRs, mated males are selected to provide care [22], but what should unmated males without offspring do?…”

Ocean acidification affects fish spawning but not paternity at CO 2 seeps

“…DNA from 10 dominant nesting males and 585 eggs from 10 nests (n ¼ 5 at ambient and n ¼ 5 at high-CO 2 conditions) was extracted using magnetic bead-mediated robotic extraction (Verde Labs Genomic DNA Extraction Chemistry on a Biosprint96 Extraction Robot). All samples were amplified using six microsatellite loci developed for S. ocellatus (Soc1017, Soc1063, Soc1109, Soc1198, Soc3121, Soc3200) and previously used for paternity assignment in this species [20]. Primer lengths were modified to allow all six loci to be used in combination in a single PCR.…”

“…Ocellated wrasse 'dominant males' build nests and provide parental care to eggs, attract females for pair spawning, chase off sexual competitors ('satellite' and 'sneaker' males) [18] and sometimes refuse to mate when other males are prevalent [19]. Satellite males cooperate with dominant males to attract females and drive away sneakers, but they also engage in sneak fertilization of the eggs [20,21]. Sneaker males, which release more sperm per spawn than dominant nesting males or satellites, do not cooperate or care and only attempt to sneak spawn [19].…”

“…Sneaker males, which release more sperm per spawn than dominant nesting males or satellites, do not cooperate or care and only attempt to sneak spawn [19]. Thus, high levels of sperm competition occur in the wild [20]. We filmed multiple wrasse nests at present-day ambient-CO 2 conditions (approx.…”