Abstract
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 two-pup 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.
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 two-pup 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.
| Original language | English |
|---|---|
| Pages (from-to) | 586-600 |
| Number of pages | 15 |
| Journal | Marine and Freshwater Research |
| Volume | 74 |
| Issue number | 7 |
| Early online date | 19 Apr 2023 |
| DOIs | |
| Publication status | Published - 2023 |
Bibliographical note
Copyright the Author(s) 2023. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.Keywords
- elasmobranch
- genetics
- hybrid
- mating system
- polyandry
- pristiophorid
- reproductive biology
- single nucleotide polymorphisms