Reproductive Biology of the Fossorial Snake Apostolepis gaboi (Elapomorphini): A Threatened and Poorly Known Species from the Caatinga Region

Autor(es)

Braz, Henrique B. ^[1] ; Kasperoviczus, Karina N. ^[1] ; Guedes, Thais B. ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Inst Butantan, Lab Ecol & Evolucao, Av Vital Brasil 1500, BR-05503900 Sao Paulo, SP - Brazil

^[2] Univ Estadual Maranhao, Ctr Estudos Super Caxias, Programa Posgrad Biodiversidade Ambiente & Saude, Praca Duque Caxias S-N, BR-65604380 Caxias, MA - Brazil

^[3] Univ Gothenburg, Dept Biol & Environm Sci, Gothenburg Global Biodivers Ctr, Box 461, SE-40530 Gothenburg - Sweden

• Tipo de documento: Artigo Científico
• Fonte: South American Journal of Herpetology; v. 14, n. 1, p. 37-47, APR 2019.
• Citações Web of Science: 0

Resumo

Knowledge of reproductive biology is essential to understand the intrinsic traits of any species and to elaborate effective conservation strategies, particularly for threatened species. Despite recent advances, knowledge on the reproductive biology of snakes remains deficient for most species, especially for tropical fossorial taxa. Apostolepis gaboi is a psammophilous, fossorial, and threatened snake endemic of the Quaternary Sand Dunes of the Sao Francisco River, Caatinga domain. Here, we present information on its reproductive biology based on macroscopic and microscopic data obtained from the examination of all specimens preserved in Brazilian museums. Specifically, we addressed sexual maturity, sexual dimorphism, clutch size, timing of gametogenesis, activity of the sexual segment of the kidney (SSK), and female sperm storage. Apostolepis gaboi is one of the smallest species of the genus. Females attain sexual maturity at larger body sizes and grow larger than males. However, adult females have relatively shorter tails than males. We found no sexual dimorphism in body circumference and head size. Clutch size is small and averages 4.5 eggs. All males from the wet season showed testes in spermiogenesis, ductus deferentia packed of sperm, and SSK hypertrophied and secretory. Secondary vitellogenesis also occurs in the wet season. Moreover, females in early vitellogenesis from the wet season showed sperm stored in the posterior infundibulum. Mating occurs in the second half of the wet season, as suggested by the finding of aggregations of sperm in the uterine lumen of a female in early secondary vitellogenesis. Mating is associated with gonadal activity in males. Sperm storage confers flexibility for females to ovulate at the most suitable time in an unpredictable habitat such as the Caatinga. Apostolepis gaboi exhibits similarities (association between mating and spermiogenesis, small clutch) and differences (absence of sexual dimorphism in head size and stoutness) compared with another Elapomorphini species. Lastly, we argue that some of the intrinsic traits of A. gaboi (small clutch and small body size) may increase its vulnerability to extinction, raising additional concerns to its conservation. (AU)

• Processo FAPESP: 14/18837-7 - Revelando os limites ocultos do agrupamento das espécies: uma abordagem inter-metodológica para identificação de bioregiões de serpentes neotropicais
• Beneficiário: Thaís Barreto Guedes da Costa
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 13/04170-8 - Biogeografia histórica das serpentes da diagonal de formações abertas da América do Sul
• Beneficiário: Thaís Barreto Guedes da Costa
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado