Environmental parameters and parasitism in common carp ( Cyprinus carpio Linnaeus, 1758) caught from Oubeira Lake (North-East of Algeria)

摘要

This study pertains to biometry and parasitism of the common carp captured in Lake Oubeira. This involved collection of 360 carp specimens,which were weighed and measured before being dissected to harvest the parasites. The size of the carp in Lake Oubeira varied from 11 to 51cmin length, although more than 70% did not exceed 31cm in length. This fraction of the studied population exhibited isometric growth, with acondition factor that did not exceed 1.15.The application of the Von Bertalanffy equation shows that Carps of Lake Oubeira have an asymptoticlength of 55.65 cm and a maximum length of 53cm with a growth rate of about 0.22 year -1. The Observation of anatomical morphologicalcharacters of 869 parasites collected allowed us to identify a Monogenea (Dactylogyrus anchoratus) a Crustacea (Argulus foliaceus), twotapeworms (Bothriocephalus acheilognathi and the larval form of Ligula intestinalis) and nematode (larvae Contracaecum sp.). The latter isreported for the first time in the general cavity of C. carpio originating from Oubeira Lake. The Survey of the evolutionary dynamic ofparasitism reveals that Contracaecum sp present throughout the year; and affects over 30% of carp. The Statistical analysis showed that thedistribution of parasites is related to the season and the fish size. The use of principal component analysis shows that water temperature iscorrelated positively with the distribution of contracaecum sp, D. anchoratus and A.foliaceus. These parasites were more frequents in summerand autumn when water temperature and suspended material present the highest values, in contrary; water temperature is correlated negativelywith the distribution of B.acheilognathi and L.intestinalis. It appears from this study that the water temperature has a great influence ondistribution of parasites.