High frequency of multiple paternity in the largest rookery of Mediterranean loggerhead sea turtles (original) (raw)
Related papers
A Review of Patterns of Multiple Paternity Across Sea Turtle Rookeries
Advances in marine biology, 2018
Why females would mate with multiple partners and have multiple fathers for clutches or litters is a long-standing enigma. There is a broad dichotomy in hypotheses ranging from polyandry having benefits to simply being an unavoidable consequence of a high incidence of male-female encounters. If females simply give in to mating when it is too costly to avoid being harassed by males (convenience polyandry), then there should be a higher rate of mating as density increases. However, if females actively seek males because they benefit from multiple mating, then mating frequency, and consequently the incidence of multiple paternity of clutches, should be high throughout. To explore these competing explanations, here we review the incidence of multiple paternity for sea turtles nesting around the World. Across 30 rookeries, including all 7 species of sea turtle, the incidence of multiple paternity was only weakly linked to rookery size (r=0.14). However, using high resolution at-sea GPS t...
Journal of Experimental Marine Biology and Ecology, 2017
Sea turtles are promiscuous breeders with both males and females mating multiply. Due to this mating system, multiple paternity (MP) occurs in sea turtle clutches, and the frequency of MP varies greatly within and among species. In this study, the paternity of a population of loggerhead sea turtles (Caretta caretta) nesting on Dalyan Beach in Turkey was investigated using two highly polymorphic microsatellite markers (CcP2F11 and CcP7C06). Tissue samples collected from randomly selected hatchlings (a total of 522 hatchlings) from two to three successive clutches (a total of 25 clutches) of 10 nesting females were used for paternity analysis with an average sampling effort of 28.2% of offspring per clutch. Evidence of MP in seven out of 10 females (70%) was found, and it was detected that four out of these seven females mated with at least two males, whereas the remaining three females with at least three males. By analysing the successive clutches of females, it was detected that both the number and genotype of contributing sires was same in all clutches of a given female, possibly due to the lack of successful inter-nesting mating in this population. The high frequency of MP implies the possible high genetic diversity within this population. This study indicates that the density of individuals may be the reason of the high frequency of MP in this relatively small population because mating takes place mainly in a narrow area in Dalyan. The possible mating behaviours of the sea turtles and their population structures were discussed in light of the high frequency of MP within this population reported for the first time.
Within-season shifts in multiple paternity patterns in mass-nesting olive ridley sea turtles
Endangered Species Research, 2021
ABSTRACT: Multiple paternity is common to all sea turtle species, but its causes and consequences are hard to ascertain and the behaviors and success of males difficult to observe. This study aims to describe patterns of multiple paternity for olive ridley turtles Lepidochelys olivacea at Playa de Escobilla, an ‘arribada’ (mass-nesting) site on the Mexican Pacific coast with over a million clutches laid each reproductive season. A total of 15 females and their hatchlings were sampled during 3 arribada events which occurred over the 2016−2017 nesting season. Females and hatchlings (N = 329) were genotyped at 5 microsatellite loci, from which we inferred the alleles of 46 contributing males. multiple paternity was detected in 60% of the analyzed clutches, which were sired by a range of 2 to 7 males. Multiple paternity rates differed significantly across arribada events, suggesting more males achieved fertilizations earlier in the breeding season. Paternal contribution in 6 of the clutches with multiple paternity was skewed towards a single male; the remaining clutches had a homogeneous male contribution. However, our results are based on relatively small within-arribada sample sizes. The frequency of multiple paternity among turtle clutches laid on this arribada beach could be related to the density of breeding individuals in the reproductive patch off Playa de Escobilla, rather than to the nesting population size or female size
Multiple paternity in egg clutches of hawksbill turtles (Eretmochelys imbricata)
Conservation Genetics, 2011
We present the first data collected on the genetic mating system of the hawksbill turtle Eretmochelys imbricata, the only marine turtle not studied to date. We examined paternity within 12 egg clutches from ten female hawksbill turtles from Sabah Turtle Islands, Malaysia. A total of 375 hatchlings were analysed using five microsatellite markers. Results demonstrated that clutches from two out of ten females were sired by multiple males (maximum of two). Although at a low frequency, observation of multiple paternity indicates that hawksbill turtles exhibit the same genetic mating system (polyandry) as observed for other species of marine turtles. Consistent paternity across multiple clutches laid by individual females in one breeding season supports the hypothesis that sperm are stored from mating prior to nesting and are then used to fertilize all subsequent clutches of eggs that season.
Female sea turtles are promiscuous, with clutches of eggs often sired by multiple males and rates of multiple paternity varying greatly within and across species. We investigated levels of multiple paternity in loggerhead sea turtles (Caretta caretta) from three rookeries in Western Australia by analysing polymorphic species-specific genetic markers. We predicted that the level of multiple paternity would be related to female population size and hence the large rookery at Dirk Hartog Island would have higher rates of multiple paternity than two smaller mainland rookeries at Gnaraloo Bay and Bungelup Beach. Contrary to our prediction, we found highly variable rates of multiple paternity among the rookeries that we sampled, which was unrelated to female population size (25% at Bungelup Beach, 86% at Gnaraloo Bay, and 36% at Dirk Hartog Island). Approximately 45 different males sired 25 clutches and the average number of sires per clutch ranged from 1.2 to 2.1, depending on the rookery sampled. The variance in rates of multiple paternity among rookeries suggests that operational sex ratios are variable in Western Australia. Periodic monitoring would show whether the observed patterns of multiple paternity for these three rookeries are stable over time, and our data provide a baseline for detecting shifts in operational sex ratios.
PeerJ, 2015
Despite the long debate of whether or not multiple mating benefits the offspring, studies still show contradictory results. Multiple mating takes time and energy. Thus, if females fertilize their eggs with a single mating, why to mate more than once? We investigated and inferred paternal identity and number of sires in 12 clutches (240 hatchlings) of green turtles (Chelonia mydas) nests at Tortuguero, Costa Rica. Paternal alleles were inferred through comparison of maternal and hatchling genotypes, and indicated multiple paternity in at least 11 of the clutches (92%). The inferred average number of fathers was three (ranging from 1 to 5). Moreover, regression analyses were used to investigate for correlation of inferred clutch paternity with morphological traits of hatchlings fitness (emergence success, length, weight and crawling speed), the size of the mother, and an environmental variable (incubation temperature). We suggest and propose two different comparative approaches for evaluating morphological traits and clutch paternity, in order to infer greater offspring survival. First, clutches coded by the exact number of fathers and second by the exact paternal contribution (fathers who gives greater proportion of the offspring per nest). We found significant differences (P < 0.05) in clutches coded by the exact number of fathers for all morphological traits. A general tendency of higher values in offspring sired by two to three fathers was observed for the length and weight traits. However, emergence success and crawling speed showed different trends which unable us to reach any further conclusion. The second approach analysing the paternal contribution showed no significant difference (P > 0.05) for any of the traits. We conclude that multiple paternity does not provide any extra benefit in the morphological fitness traits or the survival of the offspring, when analysed following the proposed comparative statistical methods.
Despite the long debate of whether or not multiple mating benefits the offspring, studies still show contradicting results. Multiple mating takes time and energy. Thus, if females fertilize their eggs with a single mating, why to mate more than once? We investigated and inferred paternal identity and number of sires in 12 clutches (240 hatchlings) of green turtles (Chelonia mydas) nests at Tortuguero, Costa Rica. Paternal alleles were inferred through comparison of maternal and hatchling genotypes, and indicated multiple paternity in at least 11 of the clutches (92%). The inferred average number of fathers was three (ranging from 1 to 5). This in returns suggests that most females successfully got fecundated by at least three males. Moreover, regression analyses were used to investigate for correlation of inferred clutch paternity with morphological traits of hatchlings fitness (emergence success, length, weight and crawling speed); and size of the mother; and an environmental varia...
Heredity, 2002
Multiple paternity in the olive ridley sea turtle (Lepidochelys olivacea) population nesting in Suriname was demonstrated using two microsatellite loci, viz., Ei8 and Cm84. The large number of offspring sampled per clutch (70 on average, ranging from 15 to 103) and the number of alleles found at the two loci (18 and eight alleles, respectively) enabled unambiguous assessment of the occurrence of multiple paternity. In two out of 10 clutches analysed, the offspring had been sired by at least two males, which was confirmed at both loci. In both clutches, unequal paternity occurred: 73% and 92% of the offspring had been sired by the primary male. The probability of detecting multiple paternity was 0.903, and therefore there is a small chance that multiple
Prevalence of polygyny in a critically endangered marine turtle population
Journal of Experimental Marine Biology and Ecology
Genetic analyses of nuclear DNA (e.g., microsatellites) are a primary tool for investigating mating systems in reptiles, particularly marine turtles. Whereas studies over the past two decades have demonstrated that polyandry (i.e., females mating with multiple males) is common in marine turtles, polygyny (i.e., males mating with multiple females) has rarely been reported. In this study we investigated the mating structure of Critically Endangered hawksbill turtles (Eretmochelys imbricata) at Bahía de Jiquilisco in El Salvador, one of the largest rookeries in the eastern Pacific Ocean. We collected genetic samples from 34 nesting females and hatchlings from 41 clutches during the 2015 nesting season, including one nest from each of 27 females and two nests from seven additional females. Using six highly polymorphic microsatellite loci, we reconstructed the paternal genotypes for 22 known male turtles and discovered that seven (31.8%) sired nests from multiple females, which represents the highest polygyny level reported to date for marine turtles and suggests that this is a common mating structure for this population. We also detected multiple paternity in four (11.8%) clutches from the 34 females analyzed, confirming polyandrous mating strategies are also employed. The high level of polygyny we documented suggests there may be a limited number of sexually mature males at Bahía de Jiquilisco; a scenario supported by multiple lines of empirical evidence. Our findings highlight key management uncertainties, including whether polygynous mating strategies can compensate for potential ongoing feminization and the low number of adult males found for this and possibly other marine turtle populations.
Journal of Experimental Marine Biology and Ecology (JEMBE), 2015
Females of all seven living species of sea turtles are known to be polyandrous and show multiple paternity. The frequency of multiple paternity varies among species, and among populations of the same species. In the olive ridley sea turtle (Lepidochelys olivacea), multiple paternity levels correlate with the abundance of individuals in the mating system, being much higher in arribada rookeries than in solitary nesting sites. We used two highly polymorphic microsatellite markers (Cm84 and Or1) to assess the level of multiple paternity in an olive ridley solitary population nesting in the Gulf of Fonseca, Honduras. We found evidence of multiple paternity in 6 out of 8 clutches (75%), with a minimum number of two fathers in four clutches, and a minimum of three in the remaining two clutches. This high level of multiple paternity in a small solitary population suggests that some of the females nesting in Honduras may be coming from proximal Nicaraguan arribada nesting beaches. Historical evidences and recent satellite telemetry data support this hypothesis. In addition, we show that multiple paternity studies can be effectively performed in the absence of maternal samples, and that pooled DNA samples can be used with results comparable to individual hatchling sampling in multiple paternity analyses.