Effect of mixed and artificial feeding on the growth performance of Gattan Luciobarbus xanthopterus Heckel, 1843 larvae

This work aimed to study the rearing feasibility of Luciobarbus xanthopterus larvae using artificial and mixed (live (Chlorella sp.) + artificial) food and their effects on their growth performance during early development. Larvae (1.65 cm in length and 0.02 g weight) were obtained from a Marine Science Hatchery and cultured in indoor tanks for 35 days. the larvae fed mixed feed T1 and artificial feed T2 (fish meal + soybean meal). The results showed that the larvae of T1 treatment outperformed significantly in final length, final weight, final weight gain, daily and specific growth rate, which amounted to 3.44 cm, 0.3568 g, 0.3368 g, 0.0096 g/day, and 8.2185 % weight/day, respectively. Also, the results showed that larvae fed on T1 grew faster. The present study showed that applying a mixture of artificial and live food after four weeks' age i.e. after absorption of the yolk sac for feeding larvae can reduce the costs of producing and providing better growth and survival rates

Short-term assessment of heavy metals in surface waters of the Shatt Al-Arab River

The Shatt Al-Arab River's water quality deteriorates naturally due to salinity intrusion, and freshwater sources decrease. Seven sampling locations along the Shatt Al-Arab River in southern Iraq were used to examine the level of six heavy metals, including Cu, Cd, Ni, Co, Mn, and Fe, during Januar-December 2021. Salinity levels in the study area ranged from 1.55 upstream to 35.15 g/L downstream of the study area. The pH of surface water ranged 7.545-8.325, indicating alkaline conditions. The concentrations of six heavy metals, viz Cu, Cd, Ni, Mn, Co, and Fe in the study area were 3.741±4.219, 3.654±4.169, 7.700± 6.251, 2.551±3.898, 2.292±3.996, and 18.236±5.583 µg/L, respectively, which decreased in the order of Fe > Ni > Cu > Cd > Mn > Co. There was a considerable change in the quantity of heavy metals throughout the year, with the summer months having the highest concentration. There is a correlation between seawater intrusion and the concentration of heavy metals in the surface waters. The mean levels of the heavy metals were below the allowed values of WHO drinking water guidelines