First evidence of multiple paternity in the blue shark (<i>Prionace glauca</i>)

Armada-Tapia, Sofía; Castillo‐Géniz, José Leonardo; Victoria-Cota, Nelva; Arce-Valdés, Luis Rodrigo; Enríquez‐Paredes, Luis M.

doi:10.1111/jfb.15272

Cited by 3 publications

(2 citation statements)

References 34 publications

(62 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, sexual selection is only thought to favour the evolution of male‐biased SSD, where a high degree of territoriality, sperm competition or parental care is observed (Horne et al., 2020 ). Direct parental care is unknown in elasmobranchs (Carrier et al., 2004 ), and indeed would be unexpected given the prevalence of multiple paternity in the clade (Armada‐Tapia et al., 2023 ). There is no evidence of widespread territoriality in elasmobranchs and although sperm competition is known, this data come from a tiny fraction of extant species (Rowley et al., 2019 ).…”

Section: Discussionmentioning

confidence: 99%

The origins and drivers of sexual size dimorphism in sharks

Gayford,

Sternes

2024

Ecology and Evolution

View full text Add to dashboard Cite

While sexual size dimorphism (SSD) is abundant in nature, there is huge variation in both the intensity and direction of SSD. SSD results from a combination of sexual selection for large male size, fecundity selection for large female size and ecological selection for either. In most vertebrates, it is variation in the intensity of male–male competition that primarily underlies variation in SSD. In this study, we test four hypotheses regarding the adaptive value of SSD in sharks—considering the potential for each of fecundity, sexual, ecological selection and reproductive mode as the primary driver of variation in SSD between species. We also estimate past macroevolutionary shifts in SSD direction/intensity through shark phylogeny. We were unable to find evidence of significant SSD in early sharks and hypothesise that SSD is a derived state in this clade, that has evolved independently of SSD observed in other vertebrates. Moreover, there is no significant relationship between SSD and fecundity, testes mass or oceanic depth in sharks. However, there is evidence to support previous speculation that reproductive mode is an important determinant of interspecific variation in SSD in sharks. This is significant as in most vertebrates sexual selection is thought to be the primary driver of SSD trends, with evidence for the role of fecundity selection in other clades being inconsistent at best. While the phylogenetic distribution of SSD among sharks is superficially similar to that observed in other vertebrate clades, the relative importance of selective pressures underlying its evolution appears to differ.

show abstract

Section: Discussionmentioning

confidence: 99%

The origins and drivers of sexual size dimorphism in sharks

Gayford,

Sternes

2024

Ecology and Evolution

View full text Add to dashboard Cite

show abstract

“…Some elasmobranch species do not appear to exhibit multiple paternity even if its occurrence is widespread within the family. Within the family Carcharhinidae, for example, 11 of the 13 species examined thus far have been shown to exhibit multiple paternity (Bester-van der Merwe et al 2019;Lamarca et al 2020;Nash et al 2021;Armada-Tapia et al 2023), with the two exceptions being the tiger shark [Galeocerdo cuvier (Holmes et al 2018;Pirog et al 2020)] and Galapagos shark [Carcharhinus galapagensis (Daly-Engel et al 2006)]. However, analysis of C. galapagensis comes with the caveat that only one litter was available for study (Daly-Engel et al 2006).…”

Section: Introductionmentioning

confidence: 99%

First evidence of multiple paternity and hybridisation in Australian sawsharks

2023

View full text Add to dashboard Cite

Context. Knowledge of sawshark reproductive biology is limited to general parameters such as reproductive mode and litter size. The mating system is currently unknown. Aim. To test for multiple paternity in the common (Pristiophorus cirratus) and southern (Pristiophorus nudipinnis) sawshark and investigate the occurrence of hybridisation between these two species. Methods. Pups from a single litter of each species and an adult P. nudipinnis displaying mismatches in its morphology and mitochondrial DNA were genotyped with nuclear single-nucleotide polymorphisms (SNPs). Multiple paternity was assessed using pairwise relatedness and sibship analysis, and hybridisation was examined using three approaches (principal-component analysis, admixture analysis and clustering with NewHybrids). Key results. Multiple paternity was detected in both species, with two males siring the seven-pup litter in P. cirratus and two males siring the twopup litter in P. nudipinnis. Hybridisation between the two species was also confirmed, with the mismatched adult identified as a first-generation hybrid. Conclusions. The mating system of sawsharks involves polyandry, and hybridisation between the two co-occurring Australian species is possible. Implications. These results provide new information on sawshark reproductive biology and highlight the need for combined use of mitochondrial and nuclear markers in future genetic studies involving these species.

show abstract