Life History Traits and Longevity of the Invasive Asian Common Toad <i>Duttaphrynus melanostictus</i> (Schneider, 1799) in Madagascar
Fabio Maria Guarino,
Franco Andreone,
Marcello Mezzasalma,
Fulvio Licata,
Simona Puoti,
Bárbara Santos,
Walter Cocca,
Jean Francois Solofoniaina Fidy,
Serge Herilala Ndriantsoa,
Jean Noel,
Tsanta Fiderana Rakotonanahary,
Rodino Fetrarijahona Harison,
Gaetano Odierna,
Angelica Crottini
Affiliations
Fabio Maria Guarino
Department of Biology, University of Naples Federico II, Via Cinthia 26, I-80126 Naples, Italy
Franco Andreone
Museo Regionale di Scienze Naturali, Via G. Giolitti, 36, I-10123 Torino, Italy
Marcello Mezzasalma
Department of Biology, Ecology and Earth Science (DiBEST)—University of Calabria, Via P. Bucci 4/B, I-87036 Rende, Italy
Fulvio Licata
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
Simona Puoti
Department of Biology, University of Naples Federico II, Via Cinthia 26, I-80126 Naples, Italy
Bárbara Santos
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
Walter Cocca
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
Jean Francois Solofoniaina Fidy
Madagascar Fauna and Flora Group, BP 442, Toamasina 501, Madagascar
Serge Herilala Ndriantsoa
Département de Biologie Animale, Université d’Antananarivo, BP 906, Antananarivo 101, Madagascar
Jean Noel
Madagascar Fauna and Flora Group, BP 442, Toamasina 501, Madagascar
Tsanta Fiderana Rakotonanahary
Turtle Survival Alliance, BP 8511, Antananarivo 101, Madagascar
Rodino Fetrarijahona Harison
Institut Supérieur de Science, Environnement et Développement Durable (ISSEDD), Université de Toamasina, Toamasina 501, Madagascar
Gaetano Odierna
Department of Biology, University of Naples Federico II, Via Cinthia 26, I-80126 Naples, Italy
Angelica Crottini
CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
We analyzed the body length, age structure, and age at sexual maturity of the invasive Asian common toad Duttaphrynus melanostictus from different sites in Toamasina, east Madagascar. We used skeletochronology as a proxy for age estimation, while gonads were histologically analyzed to determine the age of sexual maturity. The analysis of pooled age data from three sites investigated in 2016 showed that both sexes were larger, although not older, than those of native populations. For the individuals from Madagascar, the males were significantly smaller and younger (mean ± SD, SVL: 71.4 ± 1.6 mm; age: 1.8 ± 0.7 years) than the females (SVL: 78.42 ± 1.9 mm; age: 2.7 ± 1.3 years), when the data were pooled, but when the data were analyzed separately for each of the three sites, similar results were obtained only for one site. The oldest recorded male and female were 3 and 6 years old, respectively. Gonadal histology showed that the males and females reach sexual maturity after the first and second years of age, respectively. Further studies are needed to understand if the larger size and faster growth rates observed in the invasive population of D. melanostictus in Madagascar are a consequence of more favorable environmental conditions with respect to the native range (e.g., the availability of larger trophic niches, a lack of competitors, and lower predatory pressure), and we suggest to extend the monitoring of these life history traits to understand how they might influence the invasion.
