Multiple paternity in loggerhead turtle (Caretta caretta) nests on Melbourne Beach, Florida: a microsatellite...

Area of Science:

• Marine Biology
• Conservation Genetics
• Reproductive Ecology

Background:

• Sea turtle biology, particularly migratory patterns, presents challenges for conservation. Understanding reproductive strategies like paternity is crucial for effective management.
• Previous studies suggested multiple paternity in loggerhead turtles (Caretta caretta), but its frequency and implications remain under investigation.

Purpose of the Study:

• To investigate fine-scale population structure and paternal contributions in loggerhead sea turtle clutches on Melbourne Beach, Florida.
• To determine the incidence of multiple paternity and assess male reproductive success in this loggerhead population.

Main Methods:

• Analysis of mothers and offspring from 70 nests using microsatellite markers at two locations 8 km apart.
• Utilized two to four polymorphic microsatellite loci to genotype individuals and infer paternity.

Main Results:

• No significant fine-scale population differentiation was observed between the two sampled locations.
• Multiple paternity was frequent, with 22 out of 70 clutches sired by more than one father.
• Six clutches exhibited paternity by more than two fathers, a novel finding for sea turtles.

Conclusions:

• Multiple paternity is common in loggerhead sea turtles on Melbourne Beach, indicating males are not a limiting resource for this nesting aggregate.
• The high incidence of multiple fathers suggests a potentially complex mating system and broad male reproductive participation.