Studies on the most prevailing problems associated with fish anomalies in lake temsah

الملخص EN

Fishes used in the present study were collected from two different sites of Lake EL-Temsah.

Nile tilapia Oreochromis niloticus (150 fish / season) were collected from site (A) and Bolti akhdar Tilapia zillii (250 fish / season) were collected from site (B).

The fishes were subjected to external, x-ray, post-mortem and parasitological examinations.

Moreover, water and fish musculature were analyzed for detection of heavy metals.

The results of external and x-ray examinations performed on all O.

niloticus revealed that the prevalence of anomalies in examined fish were 7.166 %.

The seasonal prevalence of deformity was 21, 5.3, 2 and 0 % in spring, autumn, summer and winter respectively.

The anomalies recorded were represented as deformed jaws, bird like head, deformed mandible, vertebral deformities, hard structure at anal opening, unequal jaws and fusion of anal and dorsal fins.

The results also recorded that O.

niloticus with deformed mandible appeared in heavy musculature with fatty tissue surrounding the internal organ.

The results of external and x-ray examinations of T.

zillii revealed that, the prevalence of anomalies (bending of the operculum) was 1.6 %, all of which in autumn.

The results also recorded that all cases of deformity appeared in males of both fishes O.

niloticus and T.

zillii except in bird like head appeared in both males and females.

The results of water analysis revealed presence of lead, nickel, manganese and cadmium more than the permissible limits.

Besides, the results of musculature analysis of O.

niloticus and T.

zillii revealed presence of cadmium and lead exceeding the permissible limits.

Site (A) displayed a low salinity (2.77-2.80 %) while site (B) revealed high salinity reached up to (30.3-30.6 %).