Premiers résultats de l'élevage intensif de la perche européenne (Perca fluviatilis) en bassin : effet de la température et du tri sur la croissance

Abstract

Malgré un marché potentiel important, peu d'études ont examiné les possibilités de développement de l'élevage intensif de la perche (Perça fluviatilis) en bassins ou en cages. L'objectif de cette étude initiale était d'évaluer l'effet de la température et du tri en fonction du poids corporel sur la croissance de perches élevées en conditions intensives. Les essais ont été réalisés avec des alevins de perche sevrés (1,9 g) sur une alimentation artificielle, placés en bassins alimentés par de l'eau du système de refroidissement d'une centrale nucléaire. La croissance est légèrement supérieure (+ 14,5 %) à une température de 26,5 °C par Rapport à celle enregistrée à 22,9 °C. Cette différence est non significative (p>0,05), probablement parce que ces 2 températures se situent dans la gamme des températures optimales pour la croissance de la perche. Une infestation (taux de contamination : 24,5 %) par le cilié Heteropolaria sp est apparue à une température de 26,5 °C. Les perches, triées et séparées en 3 groupes distincts en fonction du poids corporel au début de l'expérience, ont présenté, après 234 jours d'élevage, une augmentation du polymorphisme de la croissance dans chaque groupe se traduisant par une superposition partielle des distributions des poids corporels. Une analyse de covariance indique que les 3 groupes ont présenté des vitesses de croissance comparables (F = 1,2). En élevage intensif, il apparaît que la perche présente une grande variabilité de croissance, ce qui renforce la nécessité de trier fréquemment les poissons. Mots-clés :Perça fluviatilis, élevage intensif, taux de croissance, température, tri, dominance sociale, Heteropolaria sp. FIRST RESULTS OF EUROPEAN PERCH (PERÇA FLUVIATILIS) INTENSIVE REARING IN TANK : EFFECT OF TEMPERATURE AND SIZE GRADING ON GROWTH. ABSTRACTDespite an important potential market in Europe few researches have examined the possibilities of intensive perch (Perca fluviatilis) culture in tanks or cages. This initial study investigated the effect of temperature and size grading on the growth of perch reared intensively in tanks supplied with warm water from the cooling system of a nuclear power plant. The trials were conducted with weaned perch fingerlings (1.9 g). Increasing the temperature from 22.9 °C to 26.5 °C resulted in a slight (+14.5 %) growth increase, although it was not significant (p > 0.05), probably because both temperatures were within the optimal thermal range of perch. At 26.5 °C, a high infestation (prevalence : 24.5 %) by the ciliate Heteropolaria sp. was recorded. Perch graded and divided into three size groups presented increasing growth polymorphism in each group and the body weight distributions overlapped between groups at the end of a 234-day experiment. Analysis of covariance indicated there was no significant difference, in growth rate between the groups (F = 1.2). The potential for very variable growth, as shown in our trials, stresses the necessity of frequent grading of young perch for intensive rearing purposes.

Growth of the Eurasian perch (Perca fluviatilis L.) reared in floating cages and in water recirculated system: first results

“…When the temperature was too high (27"C), perch grew slowly. The same observation has been made in natural conditions (Persson 1983;Jamet and Desmolles 1994 (Kestemont et al 1995). In October, when the water temperature drops below 1 5 T , it impedes perch growth.…”

“…Also, this species has shown the possibility of adapting to controlled conditions such as water recirculated systems or cages (Tamazouzt et al 1993a;Kestemont et al 1995). The use of the recirculated system should be of particular interest to perch culture in contending with a disease, such as Heterupolariu sp., as observed in opened systems (Melard et al 1995).…”

“…Preliminary studies have demonstrated that the Eurasian perch behaviour in a confined environment (gregarious behaviour, low agressivity, congregating under feeders, opportunistic feeding behaviour) is quite compatible with requirements of intensive breeding . Also, this species has shown the possibility of adapting to controlled conditions such as water recirculated systems or cages (Tamazouzt et al 1993a;Kestemont et al 1995). The use of the recirculated system should be of particular interest to perch culture in contending with a disease, such as Heterupolariu sp., as observed in opened systems (Melard et al 1995).…”

Reproductive Performance of Nile Tilapia (Oreochromis Niloticus Linnaeus, 1758) Fed on Periphyton and Rice Bran in Gemena City (Sud-Ubangi Province) in Democratic Republic of the Congo

“…These values are close to the maxima of 3.6% to 4.8% reported by Babiker &Ibrahim (1979), andSrisakultiev &Wee (1988). On the other hand, they are close to those of 6-7% recorded by Melard (1986). Macintosh et al, (1988), andShoko et al (2005) for females of the same species under fish farming conditions.…”

The energy requirements of Eurasian perch (Perca fluviatilis L.) in intensive culture

“…The mean deviation between the two variables was 5%, with a tendency for the model to slightly overestimate growth rate of large fish and underestimate growth rate of small fish in the size range evaluated. In addition, values obtained for both TGC and DEN seems to be realistic in comparison to values obtained in other studies [TGC (Mélard et al. 1995; Fontaine et al.…”