Thermal and salinity effects on locomotor performance of Thoropa taophora tadpoles (Anura, Cycloramphidae)

Autor(es)

Gallo, Antonio C. ^[1] ; Brasileiro, Cinthia A. ^[1] ; De Barros, Fabio Cury ^[1] ; De Carvalho, Jose Eduardo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Ecol & Evolutionary Biol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Integrative Zoology; v. 15, n. 1, p. 40-54, JAN 2020.
• Citações Web of Science: 0

Resumo

It is well known that environmental temperature influences several biological functions of ectotherms, notably in amphibians. The high permeability of anuran skin, associated with the effect of elevated environmental temperature, potentiates the dehydration process and this combination may restrict locomotor performance. Thoropa taophora is an endemic species from the Atlantic Rainforest whose tadpoles are semiterrestrial and predominantly diurnal, and are found in rocky seashores where they are exposed to sea spray and high temperatures. In this study we investigated how temperature and salinity conditions affect the locomotor performance in Thoropa taophora tadpoles. We also assessed how different osmotic concentrations affect the activity of the metabolic pathways that support muscle function. We measured the sprint speed of tadpoles of various sizes at different temperatures and salinities in the field. We also measured the activity of the enzymes pyruvate kinase (PK), lactate dehydrogenase (LDH) and citrate synthase (CS) in different temperatures and osmotic concentrations, and calculated the thermal sensitivity and the activity constants for each osmolality. Our results showed that, in general, sprint speed decreased with increasing temperature and salinity. However, whereas the effect of increased salinity was similar in smaller and larger tadpoles, increased temperature had a higher negative impact on sprint speed of larger tadpoles, thus indicating low thermal sensitivity of small tadpoles. PK and LDH thermal sensitivities and LDH constant of activity decreased as the osmolality increased. In conclusion, the locomotor capacity of tadpoles was decreased by temperature and salinity, which may be related to a decrease in anaerobic metabolism both in terms of sensitivity and total energy turnover through enzymatic activity. We discuss the ecological consequences, including the potential impacts on predator escape behavior promoted by changes in metabolism and locomotor performance in an early stage of development of this species. (AU)

• Processo FAPESP: 11/23010-6 - Avaliação térmica e osmótica sobre a fisiologia e o comportamento de girinos do complexo Thoropa (Anura: Cycloramphidae)
• Beneficiário: Antonio Carlos Gallo da Silva
• Linha de fomento: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 13/50741-7 - Diversidade e conservação dos anfíbios brasileiros
• Beneficiário: Célio Fernando Baptista Haddad
• Linha de fomento: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 12/50229-1 - Macro-ecologia da seleção sexual: influencia do clima sobre caracteres sexualmente selecionados em uma ampla escala geográfica
• Beneficiário: Glauco Machado
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/57712-4 - Instituto Nacional de Pesquisas em Fisiologia Comparada
• Beneficiário: Augusto Shinya Abe
• Linha de fomento: Auxílio à Pesquisa - Temático