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EFFECTS OF DIFFERENT THERMAL TREATMENTS ON THE MATERNAL INCUBATION EFFICIENCY OF THE ASTACID CRAYFISH AUSTROPOTAMOBIUS PALLIPES (LEREBOULLET,1858) UNDER CONTROLLED CONDITIONS

2001; Brill; Volume: 74; Issue: 9 Linguagem: Inglês

10.1163/15685400152682575

1568-5403

M. Sáez‐Royuela, J.D. Celada, Camino Muñoz, José Ramón Rodríguez Pérez, J.M. Carral,

Crustacean biology and ecology

[Adult freshwater crayfish, Austropotamobius pallipes, were maintained in the laboratory in such a way that mating, spawning, and maternal egg incubation took place under controlled conditions. This allowed to obtain data on reproductive biology from spawning to stage 2 juveniles. Three different thermal treatments were tested during embryonic development: a constant temperature of 11°C, ambient room temperature, and the incorporation of a cold period (3 weeks at 4°C). Females used in the three treatments tested were of a similar size (Mean Carapace Length ± Mean Standard Error = 34.06 ± 0.11 mm). Stage 2 juvenile production was not significantly different among the three regimes applied. The highest mean number of stage 2 juveniles per female (23) was obtained in animals maintained at constant temperature. Statistical differences were not detected, neither with regard to reproductive efficiency, in which the best value (33%) again was obtained at constant temperature. Although thermic manipulation thus did not provide better results as regards efficiency, this practice allowed to obtain stage 2 juveniles in different batches, spaced in time. Cangrejos de rio de la especie Austropotamobius pallipes se mantuvieron en laboratorio durante la fase reproductiva. De esta forma, apareamiento, puesta y todo el proceso de incubacion maternal de los huevos tuvieron lugar bajo condiciones controladas. Esto permitio la obtencion de datos biologicos reproductivos desde la puesta hasta el segundo estado juvenil. Durante el desarrollo embrionario, se ensayaron tres tratamientos termicos: temperatura constante de 11°C, temperatura ambiente y la inclusion de un periodo frio (3 semanas a 4°C). Las hembras presentaron una talla similar en los tres tratamientos (Longitud Media de Cefalotorax ± E.S.M. = 34,06 ± 0,11 mm). La produccion de juveniles estado 2 no mostro diferencias significativas entre regimenes termicos, aunque el numero medio mas alto obtenido por hembra (23) correspondio a animales mantenidos a temperatura constante. Igualmente, tampoco fueron detectadas diferencias significativas en los resultados de eficiencia reproductiva. El valor mas elevado (33%) fue obtenido con temperatura constante. Aunque la manipulacion termica no mejoro significativamente los resultados de eficiencia, esta practica permite la obtencion de juveniles estado 2 en diferentes lotes dentro de amplios margenes de tiempo., Adult freshwater crayfish, Austropotamobius pallipes, were maintained in the laboratory in such a way that mating, spawning, and maternal egg incubation took place under controlled conditions. This allowed to obtain data on reproductive biology from spawning to stage 2 juveniles. Three different thermal treatments were tested during embryonic development: a constant temperature of 11°C, ambient room temperature, and the incorporation of a cold period (3 weeks at 4°C). Females used in the three treatments tested were of a similar size (Mean Carapace Length ± Mean Standard Error = 34.06 ± 0.11 mm). Stage 2 juvenile production was not significantly different among the three regimes applied. The highest mean number of stage 2 juveniles per female (23) was obtained in animals maintained at constant temperature. Statistical differences were not detected, neither with regard to reproductive efficiency, in which the best value (33%) again was obtained at constant temperature. Although thermic manipulation thus did not provide better results as regards efficiency, this practice allowed to obtain stage 2 juveniles in different batches, spaced in time. Cangrejos de rio de la especie Austropotamobius pallipes se mantuvieron en laboratorio durante la fase reproductiva. De esta forma, apareamiento, puesta y todo el proceso de incubacion maternal de los huevos tuvieron lugar bajo condiciones controladas. Esto permitio la obtencion de datos biologicos reproductivos desde la puesta hasta el segundo estado juvenil. Durante el desarrollo embrionario, se ensayaron tres tratamientos termicos: temperatura constante de 11°C, temperatura ambiente y la inclusion de un periodo frio (3 semanas a 4°C). Las hembras presentaron una talla similar en los tres tratamientos (Longitud Media de Cefalotorax ± E.S.M. = 34,06 ± 0,11 mm). La produccion de juveniles estado 2 no mostro diferencias significativas entre regimenes termicos, aunque el numero medio mas alto obtenido por hembra (23) correspondio a animales mantenidos a temperatura constante. Igualmente, tampoco fueron detectadas diferencias significativas en los resultados de eficiencia reproductiva. El valor mas elevado (33%) fue obtenido con temperatura constante. Aunque la manipulacion termica no mejoro significativamente los resultados de eficiencia, esta practica permite la obtencion de juveniles estado 2 en diferentes lotes dentro de amplios margenes de tiempo.]