The effect of different cold period during maternal incubation on incubation efficiency and hatching term inAustropotamobius pallipes

Abstract

Key-words:white-clawed crayfish, egg, temperature, hatching, survival rate This study tested the effect on the incubation efficiency (E in %) and hatching term during maternal incubation of Austropotamobius pallipes of five different cold periods (duration: 45, 60, 75, 90 and 105 days) under controlled conditions and one group maintained under ambient Irish water temperatures. The six different durations of cold period, used in this study, caused six different terms of hatching from 16 March to 29 June. When compared to the group held under ambient Irish conditions with fluctuating water temperatures during the incubation period (E = 29.9 ± 4.5%), higher incubation efficiency was found in all groups under the controlled conditions (E = 73.1 ± 4.7%−41.3 ± 2.7%). In groups under controlled conditions, a positive effect of shortened cold period on incubation efficiency was found, with the highest efficiency (E = 73.1 ± 4.7%−68.8 ± 5.2%) found after the shortest cold period, while the longest cold period led to the lowest efficiency (E = 41.3 ± 2.7%). RÉSUMÉ L'effet de différentes périodes froides pendant l'incubation maternelle sur l'efficacité de l'incubation et la date d'éclosion chez Austropotamobius pallipes Mots-clés :écrevisse à pattes blanches, oeufs, température, éclosion, taux de survie Cette étude a testé l'effet, sur l'efficacité d'incubation (E en %) et la date d'éclo-sion pendant l'incubation maternelle chez Austropotamobius pallipes, de cinq périodes de froid différentes (durées : 45, 60, 75, 90 et 105 jours) en conditions contrôlées comparées à un groupe maintenu à température ambiante des eaux irlandaises. Les six différentes périodes froides, utilisées dans cette étude, conduisent à six dates d'éclosion du 16 mars au 29 juin. Quand on compare au groupe maintenu sous conditions ambiantes irlandaises comportant des variations de température pendant l'incubation (E = 29,9 ± 4,5 %), une meilleure efficacité d'incubation a été trouvée pour tous les groupes en conditions contrôlées (E = 73,1 ± 4,7 %−41,3 ± 2,7 %). Dans les groupes en conditions contrôlées, un effet positif des courtes périodes froides sur l'efficacité d'incubation a été trouvé, avec la plus forte efficacité (E = 73,1 ± 4,7 %−68,8 ± 5,2) trouvée après la période froide la plus courte, alors que l'efficacité est la plus faible (E = 41,3 ± 2,7 %) pour la période froide la plus longue.

Effect of water temperature on egg incubation time and quality of newly hatched larvae of northern pike (Esox lucius L., 1758)

“…To be economically viable, intensive culture needs a stable, high quality, year-round supply of larvae (M€ uller-Belecke and Zienert, 2008). Generally, it is possible to stagger time of fish reproduction by techniques such as out-of-season spawning (Migaud et al, 2004;Ronyai, 2007;Policar et al, 2010), shifting the spawning period (Ronyai, 2007;Muscalu-Nagy et al, 2011) and modifying egg incubation times by temperature modulation (Kucharczyk et al, 1997;Policar et al, 2004Policar et al, , 2009Drozd et al, 2009;Kupren et al, 2011). Water temperature is one of the most important factors affecting fish embryo development, incubation and hatching period (Kucharczyk et al, 1997;Drozd et al, 2009;Kupren et al, 2011).…”

Impact of dietary protein content on growth of the white-clawed crayfish Austropotamobius pallipes (Lereboullet, 1858) (Decapoda, Astacidae) in captive rearing for conservation

“…However, due to the lack of economic interest in this crayfish species, there have only been very few studies on the captive rearing of A. pallipes (Pérez et al, 1998;Sáez-royuela et al, 2002;Carral et al, 2004;Paglianti and Gherardi, 2004;Scalici and Gibertini, 2007;Policar et al, 2009Policar et al, , 2010Policar et al, , 2011. Current knowledge in regard to the nutritional needs of captive reared A. pallipes for optimal growth efficiency, in particular, still remains sparse.…”