Where have all the tadpoles gone? Individual genetic tracking of amphibian larvae until adulthood

Abstract

Reliably marking larvae and reidentifying them after metamorphosis is a challenge that has hampered studies on recruitment, dispersal, migration and survivorship of amphibians for a long time, as conventional tags are not reliably retained through metamorphosis. Molecular methods allow unique genetic fingerprints to be established for individuals. Although microsatellite markers have successfully been applied in mark–recapture studies on several animal species, they have never been previously used in amphibians to follow individuals across different life cycle stages. Here, we evaluate microsatellites for genetic across-stages mark–recapture studies in amphibians and test the suitability of available software packages for genotype matching. We sampled tadpoles of the dendrobatid frog Allobates femoralis, which we introduced on a river island in the Nature Reserve ‘Les Nouragues’ in French Guiana. In two subsequent recapture sessions, we searched for surviving juveniles and adults, respectively. All individuals were genotyped at 14 highly variable microsatellite loci, which yielded unique genetic fingerprints for all individuals. We found large differences in the identification success of the programs tested. The pairwise-relatedness-based approach, conducted with the programs kingroup or ML-Relate, performed best with our data set. Matching ventral patterns of juveniles and adult individuals acted as a control for the reliability of the genetic identification. Our results demonstrate that microsatellite markers are a highly powerful tool for studying amphibian populations on an individual basis. The ability to individually track amphibian tadpoles throughout metamorphosis until adulthood will be of substantial value for future studies on amphibian population ecology and evolution.

Purging putative siblings from population genetic data sets: a cautionary view

“…Results of sibship reconstruction often differ depending on the method used (Ringler et al . ) and, for a given method, can differ depending on the type of markers used (Linløkken et al . ).…”

Hierarchical decision‐making balances current and future reproductive success

“…The study was conducted in an experimental A. femoralis population that had been introduced in a controlled manner on a 5‐ha river island (Ringler et al., ) in a lowland rainforest near “Saut Pararé” field camp (4°02′N, 52°41′W) of the CNRS “Nouragues Ecological Research Station” in the nature reserve “Les Nouragues,” French Guiana. In March 2012, we collected 1,800 A. femoralis tadpoles from artificial pools on the adjacent mainland (Ringler, Pašukonis, et al., ; Ringler, Hödl, et al., ), took a small tail clip as a tissue sample and released them on the river island, which was previously uninhabited by this species (Ringler, Mangione, & Ringler, ). We distributed the tadpoles across 20 artificial plastic pools (volume ~15 L, interpool distance 10 m, 90 tadpoles per pool, Figure ) that were dug level into the ground and filled by rain, and recorded this “natal pool” for every tadpole.…”

“…Tissue was sampled from all tadpoles by clipping a small piece of tail and immediately preserving it in 96% ethanol (Ringler et al., ). Afterwards, all tadpoles were released back to their original pool.…”

“…The genotypes of all adult individuals were already available from (Ringler et al., ), where all adult individuals were assigned to their respective founder tadpole from 2012 using genetic similarity matching. The tadpole release data from 2012 allowed us to reconstruct the natal pools of all adult individuals found in 2013.…”

A model for first‐estimates of species‐specific, age‐specific mortality from centralized band‐recovery databases

“…Other species groups may fulfill these criteria, for instance, marked salmonids (Gilbreath et al 1976); cetaceans individually recognized from scarring or coloration patterns (Constantine et al 2012, but see Carroll et al 2016 for a caveat of this technique for estimates including juvenile ageclasses); sea turtles, reptiles, and amphibians recognized by permanent marks (Spellerberg 1977, Balazs 1999, Waudby and Petit 2011; and any mammal species that may be tagged (Diefenbach and Alt 1998). Individual-precision genetic identification of individuals may allow this technique to be used without requiring the invasive marking of individuals (see Waits et al 2001, Banks et al 2003a, b, and Efford et al 2009), as genomic approaches can yield cost-effective, unambiguous recognition of individuals (Szabolcsi et al 2014, Ringler et al 2015, Woodruff et al 2015.…”