Abstract
In this paper, it is proposed to identify the major components related to the flow of matter flows between
the various components of the trophic pyramid of the top (fish populations) towards the base
(zooplanktonic stands). The stands of Copepods and two clupeidae (Sardina pilchardus and Sardinella
aurita) selected as models within certain regions of the Algerian coast.
From this contribution, we will try to answer two questions: what are the species that make up the
biodiversity of the Zooplankton stands of Copepods and their quantitative distributions within the
epipelagic water column; That these species (prey) represent in the food bowl of clupeid predators (S.
pilchardus and S. aurita) and are subjected to a preferential selection
In this study, the stands studied (Copepods and Clupeidae) originate from the central region, and
particularly within the Bay of Bou Ismail. The latter is located between 2 ° 54 'East - 36 ° 48' North and
2 ° 24 'East - 36 ° 38' North.
The fauna of Epipelagic Copepods is composed of 22 species. The faunistic counts (see Chapter
IV.1.3.2) and the Ascending Hierarchical Classification have shown a contingent of the so-called main
populations (Temora stylifera, Nannocalanus minor Pareucalanus attenuatus Centropages typicus, C.
chierchiae, C. violaceus, C. hamatus, Eucalanus Elongatus). These species are frequent (more than 75%
of the zooplankton crops) and abundant (more than 5 ind.m-3).
The modeling of prey interactions (herbivorous copepods) - predators (carnivorous copepods) was
approached by the Lotka - Voltera model. Top - down (descending) and bottom - up (ascending) material
flows identified at the sampling stations. The main species have a role in the transfer of organic matter
within the pelagic ecosystem. The regulation of this carbon flux varies from one position to another.
The diet of the sardine and the allache is composed mainly of crustaceans Copepods (80% and 91%).
The Prey Overlap Index (D and O > 0.6) confirmed this result.
The statistical analyzes of the presence-absence (Cochran test and Jaccard distance) between the
different trophic compartments (Copepods within the water column and feeding bowls of the fish
populations) showed qualitative heterogeneity.
Key words: Algerian coast, Zooplankton biodiversity, Small pelagics, Trophic interactions.
In this paper, it is proposed to identify the major components related to the flow of matter flows between
the various components of the trophic pyramid of the top (fish populations) towards the base
(zooplanktonic stands). The stands of Copepods and two clupeidae (Sardina pilchardus and Sardinella
aurita) selected as models within certain regions of the Algerian coast.
From this contribution, we will try to answer two questions: what are the species that make up the
biodiversity of the Zooplankton stands of Copepods and their quantitative distributions within the
epipelagic water column; That these species (prey) represent in the food bowl of clupeid predators (S.
pilchardus and S. aurita) and are subjected to a preferential selection
In this study, the stands studied (Copepods and Clupeidae) originate from the central region, and
particularly within the Bay of Bou Ismail. The latter is located between 2 ° 54 'East - 36 ° 48' North and
2 ° 24 'East - 36 ° 38' North.
The fauna of Epipelagic Copepods is composed of 22 species. The faunistic counts (see Chapter
IV.1.3.2) and the Ascending Hierarchical Classification have shown a contingent of the so-called main
populations (Temora stylifera, Nannocalanus minor Pareucalanus attenuatus Centropages typicus, C.
chierchiae, C. violaceus, C. hamatus, Eucalanus Elongatus). These species are frequent (more than 75%
of the zooplankton crops) and abundant (more than 5 ind.m-3).
The modeling of prey interactions (herbivorous copepods) - predators (carnivorous copepods) was
approached by the Lotka - Voltera model. Top - down (descending) and bottom - up (ascending) material
flows identified at the sampling stations. The main species have a role in the transfer of organic matter
within the pelagic ecosystem. The regulation of this carbon flux varies from one position to another.
The diet of the sardine and the allache is composed mainly of crustaceans Copepods (80% and 91%).
The Prey Overlap Index (D and O > 0.6) confirmed this result.
The statistical analyzes of the presence-absence (Cochran test and Jaccard distance) between the
different trophic compartments (Copepods within the water column and feeding bowls of the fish
populations) showed qualitative heterogeneity.
Key words: Algerian coast, Zooplankton biodiversity, Small pelagics, Trophic interactions.