Como variam a condição corpórea e as reservas energéticas de Eleutherodactylus johnstonei (Anura) durante a reprodução?
Data
2021-08-03
Tipo
Trabalho de conclusão de curso
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Resumo
A maioria das espécies de anuros apresenta um período de atividade sazonal devido a ectotermia e pele permeável. Durante condições adversas (frio e seco), os anuros exibem ajustes fisiológicos como a manutenção de um estado de depressão metabólica, sendo dependentes de estoques endógenos de energia. A condição corpórea indica a saúde dos indivíduos. Ela pode variar de acordo com a temperatura e disponibilidade de alimento. Em anuros que passam por um período de inatividade, espera-se que os indivíduos apresentem uma melhor condição corpórea no final da reprodução e, também que as reservas energéticas sejam menores no início da reprodução devido ao uso durante a inatividade. Eleutherodactylus johnstonei é um anuro noturno de pequeno porte, nativo das Pequenas Antilhas e com população estabelecida no Brasil. A reprodução de E. johnstonei ocorre de outubro a abril. Neste estudo avaliamos a variação da condição corpórea e das reservas energéticas de machos de E. johnstonei durante a reprodução. Para isso, testamos as hipóteses de que a condição corpórea dos indivíduos no final da reprodução é superior quando comparada ao início devido à inatividade. E de que se os indivíduos entram em depressão metabólica, as reservas energéticas são menores no início e maiores no final da reprodução devido à preparação à inatividade. Coletamos os indivíduos de E. johnstonei em uma área residencial (Jardim Petrópolis e Jardim Cordeiro) do município de São Paulo (23°37'59.8"S 46°40'58.0"W) entre outubro de 2019 e março de 2020 e entre outubro de 2020 e março de 2021. No laboratório medimos o comprimento rostro-cloacal (CRC) dos indivíduos e a massa para a determinação da condição corpórea. Quantificamos concentração de lipídeos, a área e volume do glicogênio dos fígados. A condição corpórea dos machos de E. johnstonei não variou,
mas as reservas energéticas variaram parcialmente entre o início e final da
reprodução. As reservas de carboidratos foram semelhantes entre os períodos e as
reservas de lipídeos foram maiores no início da reprodução. Os resultados indicam
que os machos de E. johnstonei armazenam reservas de gordura no início da
reprodução, no entanto não está claro quando e quanto tempo antes da reprodução este armazenamento é realizado.
Most anuran species have a period of seasonal activity due to ectothermy and permeable skin. During adverse conditions (cold and dry), anurans exhibit physiological adjustments such as the maintenance of a state of metabolic depression, being dependent on endogenous energy stores. The body condition indicates the health of the individuals. It can vary according to temperature and food availability. In anurans that go through a period of inactivity, it is expected that they have a better body condition at the end of reproduction and also that energy reserves are smaller at the beginning of reproduction due to its use during inactivity. Eleutherodactylus johnstonei is a small nocturnal frog native to the Lesser Antilles with an established population in Brazil. The reproduction of E. johnstonei occurs from October to April. In this study we evaluated the variation in body condition and energy reserves of E. johnstonei males during reproduction. We tested the hypotheses that the body condition at the end of reproduction is better when compared to the beginning due to inactivity. If the individuals go into metabolic depression, the energy reserves are smaller at the beginning and bigger at the end of reproduction due to preparation for inactivity. We collected individuals of E. johnstonei in a residential area (Jardim Petrópolis and Jardim Cordeiro) in the municipality of São Paulo (23°37'59.8"S 46°40'58.0"W) between October 2019 and March 2020 and between October 2020 and March 2021. In the laboratory, we measured the snout-vent length (SVL) and mass of the males and measured the lipids concentration and area and volume of the glycogen of the livers. The body condition of males of E. johnstonei did not vary, but the energy reserves varied partially between the beginning and the end of reproduction. Carbohydrate stores were similar between periods and lipid stores were more significant at the beginning of reproduction. Our results indicate that males of E. johnstonei store fat reserves before starting the reproduction period. However, it is not clear when and how long before reproduction this storage is carried out.
Most anuran species have a period of seasonal activity due to ectothermy and permeable skin. During adverse conditions (cold and dry), anurans exhibit physiological adjustments such as the maintenance of a state of metabolic depression, being dependent on endogenous energy stores. The body condition indicates the health of the individuals. It can vary according to temperature and food availability. In anurans that go through a period of inactivity, it is expected that they have a better body condition at the end of reproduction and also that energy reserves are smaller at the beginning of reproduction due to its use during inactivity. Eleutherodactylus johnstonei is a small nocturnal frog native to the Lesser Antilles with an established population in Brazil. The reproduction of E. johnstonei occurs from October to April. In this study we evaluated the variation in body condition and energy reserves of E. johnstonei males during reproduction. We tested the hypotheses that the body condition at the end of reproduction is better when compared to the beginning due to inactivity. If the individuals go into metabolic depression, the energy reserves are smaller at the beginning and bigger at the end of reproduction due to preparation for inactivity. We collected individuals of E. johnstonei in a residential area (Jardim Petrópolis and Jardim Cordeiro) in the municipality of São Paulo (23°37'59.8"S 46°40'58.0"W) between October 2019 and March 2020 and between October 2020 and March 2021. In the laboratory, we measured the snout-vent length (SVL) and mass of the males and measured the lipids concentration and area and volume of the glycogen of the livers. The body condition of males of E. johnstonei did not vary, but the energy reserves varied partially between the beginning and the end of reproduction. Carbohydrate stores were similar between periods and lipid stores were more significant at the beginning of reproduction. Our results indicate that males of E. johnstonei store fat reserves before starting the reproduction period. However, it is not clear when and how long before reproduction this storage is carried out.