Tolerance to the air exposition test of Hoplias lacerdae larvae and juvenile during its initial development

Abstract

O estabelecimento de parâmetros para avaliação da qualidade de larvas e juvenis produzidos intensivamente é altamente desejável. Nesse sentido, o experimento teve o objetivo de avaliar a Taxa de Resistência ao Estresse (Re) em larvas e juvenis de trairão. Larvas foram submetidas a testes para a avaliação da Re no 13&deg;, 16&deg;, 19&deg;, 23&deg; e 26&deg; dia de vida. Vinte animais foram separados em béqueres de um litro e mantidos em temperatura entre 27 e 28,5&deg;C. em seguida realizaram-se os seguintes tratamentos: E3. 3 minutos; E5. 5 minutos; E7. 7 minutos; E10. 10 minutos e E15. 15 minutos sobre o papel secante. Após 24 horas foi verificada a Re. Observou-se que a Re apresentou um aumento nos valores do 13&deg; ao 19&deg; dia em todos os tratamentos. Foram observadas elevadas Re durante todo o trabalho, sendo os menores valores (P<0,05) encontrados para E10 (67,7% no 13&deg; dia) e para E15 (41,25% no 26&deg; dia). Concluiu-se que larvas e juvenis de trairão são resistentes à exposição ao ar sobre papel secante e que exposição superior a sete minutos é mais adequada para avaliação da Re de larvas e juvenis de trairão submetidos a diferentes condições de cultivo.

The establishment of evaluation parameters for larvae and juvenile quality assessment is highly desirable. The experiment evaluated the Stress Resistance Rate (Re) on Hoplias lacerdae larvae and juveniles. Larvae on the 13th, 16th, 19th, 23rd and 26th days of life were subjected to Re evaluation tests. Twenty animals were stoked in one liter beaker and kept at 27 to 28.5&deg;C. The following treatments were applied: E3 -3 minutes; E5 - 5 minutes; E7 - 7 minutes; E10 - 10 minutes and E15 -15 minutes on drying paper. After 24 hours Re was evaluated. It was observed that Re values showed an increase from 13th to 19th day in all treatments indicating an increasing resistance related to larval development. High Re rates were observed during the whole experiment, with the lowest value (P<0.05) found on treatment E10 (67.7% on the 13th day) and E15 (41.25% on the 26th day). It could be concluded that trairao larvae and juvenile were resistant to the air exposition test on drying paper and expositions higher than seven minutes were more efficient for Re evaluation of trairao larvae and juveniles subjected to different rearing conditions.