Abstract

The crucian carp Carassius carassius (Linnaeus, 1758) is a very abundant freshwater fish and very common in Algeria, it represents an important socio-economic value. The main purpose of introducing this species into Algeria was aquaculture and the enrichment of vacant ecological niches such as dams.

We are interested to study some aspects of the biology of the C. Carassius population (Growth, Reproduction, Diet) in Béni Haoun et Ain Dalia dams. We sampled 414 specimens: (monthly sampling of 334 specimens from the Beni Haroun dam (Mila) and a random sampling of 80 individuals from Ain el Dalia dam. during a period from January to December 2015

The assessment of the physicochemical quality of the two dams shows that the water of the Béni Haroun dam has a higher level of organic pollution compared to the Ain Dalia dam, but in general the results of the analyzes were in line with the Algerian standards for water.

The scalimetry method allowed us to estimate a maximum longevity of 7 years in the Beni Haroun dam, although the maximum age of Ain Dalia fish is 5 years. The linear growth parameters of the Von Bertalanffy model show a rapid growth of Beni Haroun fish (L∞ = 34.10, K = 0.61 year-1) compared to that of Ain Dalia (L∞ = 26.84, K = 0.20 year-1). The growth of females is always faster compared to that of males in the two sites studied. (Beni Haroun : Females : L∞=34,10 ; K=0,57 year-1 ; Males : L∞=31,78 ; K=0,49 year-1) (Ain Dalia : Females : L∞=26,84 ; K=0,18 year-1 ; Males : L∞=26,10 ; K=0,16 year-1 ).

The evolution of the total weight of our sample compared to the total length (irrespective of sex) has an upper bound algometry (b> 3)for both of dams. The allometric coefficients of the size / weight ratio and eviscerated weight size of Haroun's crucian indicate a minor allometry for the entire population. We also note a minor allometry of the total population of Ain Dalia Dam. However, the eviscerated weight size relationship shows isometry for females and the combined sex, and a lower allometric for males.

The dietary habits of Carassius carassius studied at the two dams show that, whatever the site, the diet is essentially based on phytoplankton followed by zooplankton. The diet of this cyprinid is influenced by season and size; IRI percentages vary significantly by season and size classes (ANOVA, p <0.001). Algae were the main foods during winter and spring, the contributions of animal food categories (zooplankton and insects) were important in summer and autumn. However, the contributions of algae and rotifers were important in the diet of small fish while zooplankton; were important in the adult diet.

The study of reproductive biology shows that the overall sex ratio is in favor of females while its monthly evolution has shown significant differences (χ2, p <0.05).
The monitoring of the monthly evolution of the three parameters (RGS, RHS and K) of the crucian carp of the two dams has shown that it has a single spawning period covering the month of May until July in the Beni Haroun dam. and the month of April to June for the Ain Dalia.

Key Words: Carassius carassius, growth, feeding habits, reproduction, Beni Haroun Dam, Ain Dalia Dam.

Information

Item Type:	Thesis
Divisions:	» Laboratory for Terrestrial and Aquatic Ecosystems » Faculty of Natural Sciences and Life
ePrint ID:	1313
Date Deposited:	2018-06-26
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/1313

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