Producing hybrid fry from cross-breeding between Barbus xanthopterus females and Barbus sharpeyi males in marine science center hatchery

الملخص EN

The process of hybridization was carried out between female of Barbus xanthopterus X male of Barbus sharpeyi by artificial reproduction in Marine Science Center hatchery.

Environmental factors (Temperature, salinity, dissolved oxygen, and pH) of the hatchery water were measured.

The environmental factors within the optimum limits for the process of artificial breeding of these two species.

The fertilized eggs were hatched and the larvae were reared inside the hatchery for six days.

Later the hybrid larvae transferred to floating cages in the earthen pond, the initial larval weight was 5.2 mg.

The rearing of hybrid larvae continued for 20 days and the average of final length was 20 mm and average of final weight was 41mg.

65887 Trace elements (cobalt, iron, nickel, manganese, copper and cadmium) were studied at three organs (muscles, liver and gills) of the body of fish, silver carp (Hypophthalmichthys molitrix) during the period from autumn 2009 to summer 2010.

The concentrations of these elements were measured using Flame Atomic Absorption Spectrophotometry.

Results showed that the trace elements (cobalt, iron, nickel, manganese, copper and cadmium) in muscles were ranged from ((ND (spring) to 5.54 (summer) ; 40.68 (winter) to 72.10 (summer) ; 55.23 (autumn) to 69.23 (summer) ; 3.12 (winter) to 5.72 spring) ; ND (winter) to 14.34 (summer) ; 1.16 (autumn) to 2.89 (spring)) μg / g dry weight, respectively.

While in liver were ranged from ((5.22 (spring) to 16.71 (summer) ; 55.80 (winter) to 98.90 autumn) ; 70.45 (winter) to 89.18 (autumn) ; 6.01 (summer) to 10.99 (spring) ; 20.10 (autumn) to 30.22 (summer) ; 6.50 (autumn) to 12.69 (summer)) μg / g dry weight, respectively.

Also, in gills were ranged from ((11.13 (spring) to 19.36 (summer) ; 50.50 (winter) to 83.91 (summer) ; 58.28 (summer) to 78.91 (winter) ; 7.00 (summer) to 13.62 (autumn) ; 11.30 (autumn) to 23.61 (summer) 8.51 (summer) to 10.22 (winter)) μg / g dry weight, respectively.

Generally, the concentrations of these elements in liver were higher than in muscles and gills.

The trace elements concentration had been distributed during the seasons as follow : summer > spring > autumn > winter.