No abstract

The feeding behavior experiment showed that the juveniles of Macrobrachium nipponense mostly and frequently occurred on the artificial net covered wall of the experimental tanks and in all other result feeding of juvenile Macrobrachium nipponense was pelagic and benthic during 2 and 24 hour, in three parts of pond (net wall- A, water column- B and bottom-C) on bottom of ponds smooth and sand-clay, also feeding on pallet. Also showed near of found ratio was 80%, 9%, 11% and 73%, 12%, 14% during 2 hour in parts of pond of smooth and sand-clay respectively, but during 24 hour 72%, 12%, 16% and 67%, 12%, 21% in parts of pond of smooth and sand-clay respectively.

One male specimen of the species Metapenaeus stebbingi Nobili, 1904 was first recorded in November 2021 from the Iraqi territorial waters, Northwest of the Arabian Gulf. Therefore, the investigated shrimp species nominally corresponds to the original description of M. stebbing through the main diagnostic features. It must be adopted in the spread and expansion of species, a new record of the area, and a distinctive addition to the species of commercial shrimp within the Iraqi marine waters.

The bacterial content of the water of Metapenaeus affinis and Macrobrachium nipponense juvenile shrimp cultured in two salinities (3 and 15 g.L -1 ) were observed during 45 days. The initial and final weights of M. affinis were (0.939 ± 0.069 and 1.581 ± 0.183 g) in 3 g.L -1 , and (0.939 ± 0.065 and 2.274 ± 0.294 g) in 15 g.L -1 . While for M. nipponense, it was (0.914 ± 0.086 and 1.308 ± 0.070 g) in 3 g.L -1 , and (0.908 ± 0.070 and 1.086 ± 0.107 g) in 15 g.L -1 . The environmental factors were temperature 24-29 ˚C, acidity 7-8, and dissolved oxygen 5-10 g.L -1 . Bacterial contamination (CFU m.L -1 10⁶) was evident in treatment D and included four types of bacteria: Bacillus spp., Escherchia coli, Staphylococcus spp., Streptococcus spp., and Enterococcus spp. The survival rates of M. affinis during different breeding periods in the two salinities remained as follows:

This study includes an experimental hatchery design for the oriental river prawn Macrobrachium nipponense from the brackish water of Basrah region (Al-Mashab Marsh). This hatchery consist of five parts: maturation ponds (closed system), hatching of zoug jars, rearing of ponds to larva (nursery and concrete ponds), water tanks and food live of pond (fiberglass). The production capacity was 53,504-190,000 Zoea larvae, 32,355-99,560 Postlarvae. While production of the out ponds (cage two in mud and fiberglass ponds) were estimated between 4,347-24,098 larvae and 2,527-18,828 Postlarvae. Depending on results the total area of the earthen pond and the fiberglass tank, the potential production of Zoea larvae were estimated to be between 36,559-15,300,000 larvae, and between 21,248-11,954,400 Postlarvae. While the total production in all culture systems were 12,600,188-15,760,462 larvae, and between 9,753,349-12,197,630 Postlarvae.