This study was conducted to assess optimal salinity level among 0‰, 5‰, 10‰, 15‰, 20‰ and 25‰ for successful breeding of Nile tilapia, Oreochromis niloticus. The duration of study was 56 days. Brooders (48) having mean weight (male 162±0.2 g and female 160±2.5 g) were selected and stocked into hapa nets in 12 fiberglass tanks (2000-liter). Ratio among male and female was 1:3. They were fed with commercial floating pelleted feed constituting 35% crude protein with 2% body weight twice a day. Eggs were collected on weekly basis by cultch removal method. Results showed that the highest fecundity, fertility, hatchability and survival of fry were obtained on salinity of 0%-15% and significantly decreased on 20‰ and 25‰. The eggs per gram body weight were also recorded in all treatments and highest eggs were obtained i.e. 4.0-4.3 per female on 0‰-15‰. Water temperature (28.02±0.12°C), dissolved oxygen (6.4±0.02 mg/L), pH (7.47±0.04) and ammonia (less than 0.022±0.001 mg/L) were monitored throughout the study period. Water quality parameters remained within the recommended range. Our results suggest that Nile tilapia, O. niloticus may give maximum eggs up to 15‰ salinity with 92% survival of fry.

The natural resources of Pakistan, such as the Arabian Sea, the Indus Delta, dams, lakes, and mountain streams, present a variety of marine and inland fisheries potentials. These resources support numerous species with dietary and economic value. Fish and other aquatic food are major sources of protein for native people and animal populations worldwide. Fish accounts for 7% of the protein in diet and 17% in animal protein. Fish production in Pakistan rose from 214,231 metric tonnes in 1973 to 733,025 metric tonnes in 2021 at a rate of 4.9% per annum. During the same period, the amount of fish used for human consumption went from 99,368 metric tonnes to 500,866, at an annual rate of 9.7%. Fish export had increased at the rate of 18.6% from 24,623 metric tonnes in 1980 to 217,030 metric tonnes in 2021. The export values reached 496 million US$ in 2022-23. In 2021, fish imports totalled 5,770 metric tonnes. Fish for human consumption in aquatic food chains are typically sold in canned, frozen, cured, or fresh forms. Fresh marketing, freezing, and canning all require special equipment, which involves high capital costs. However, curing is a simple, low-cost preservation process that doesn't involve much in the way of material or capital expenditures. Frozen fishery products are dominant with 85%, followed by live (7%), dried (6%) and chilled (2%). Fish is also processed into meal before being added to animal feed; the bulk of processed fishmeal is used for chicken feed. 16% of the total fish production was converted to fishmeal production. With 25 currently in operation in Karachi and 30 in Gwadar, the country’s fish processing facilities are somewhat old and equipped with outdated machinery. Particularly for rural populations, fisheries resources offer sustainable development, employment opportunities, and financial rewards. Additionally, it has been noted that export statistics for fisheries are not adequately reported, which is necessary for them to be comparable to those of other countries. The study also provides sources for fisheries statistics.

This study was conducted to examine the effects of varying salinity levels (0‰-30‰ with 5% increment) on breeding of red tilapia. Brood fish were stocked in hapa nets suspended in cemented rectangular tanks (11×7×4 feet) . Three females (mean weight 145 g) and one male (140 g) were kept per tank with 2 replications. They were fed with commercial floating pellets having 35% crude protein at 2% body weight twice a day for 60 days and eggs were collected weekly. Results showed that fertilized eggs were found to be greater in number at low salinity level as compared to higher salinity level. Survival of fry ranged from 1058 to 1100 at salinity level of 0‰ – 20‰ with 5% increment, after which fry number decreased significantly (P<0.05). The fertilized eggs did not differ for the fish at salinity of 0‰ –20‰, but decreased significantly when salinity levels were increased above 25‰. Water quality parameters remained as temperature (28.1±0.2°C), dissolved oxygen (6.10±0.1 ml/l), pH (6.6±0.1 ml/l) and ammonia (0.02±0.004 ml/l) throughout the study period. Taking into consideration the number of fertilized eggs and survival of fry data attained in the present study, a salinity level of 20% is suggested for red tilapia breeding in concrete tanks.

Effect of stocking density on growth, production and survival of red tilapia (Oreochromis mossambicus × O. niloticus) were conducted in hapa for 60 days at Chilya Thatta. Tilapia fry (4.5±0.02 cm, 2.0±0.01 g) were stocked into hapa (4.5x2.4x1 m). Three treatments with two replicates were used: T1-200; T2-250 and T3-300 fry/hapa. Fry were fed twice a daily with pelleted feed containing 35% protein, 5% of total biomass. After 60 days, the highest growth were determined in T1 (49.8±0.0 g) while in T3 lowest growth (29.09±0.0 g) was recorded. Production (9.56, 10.13 and 8.12 kg/m3/60days) in T1, T2 and T3 respectively were significantly different (P0.05). Survival was significantly different among treatments (P

In this study, the suitability of four earthen, seawater ponds located in the Thatta district of Sindh province (Pakistan) was evaluated for the purpose of semi-intensive mariculture, which remains to be a severely underdeveloped branch of the agricultural industry of this populous Asian country. Initial pond soil probes were promising, as they showed a high clay and silt content. Monthly water samples were obtained in the year 2019 (from January to December), which allowed for the monitoring of water parameters, as well as the identification and relative quantification of planktic populations. As a result, the monthly variations of basic water parameters were found within optimal ranges for planktic growth (water temperature, salinity, pH, transparency, and dissolved oxygen). Bacillariophyta was the largest phytoplanktic group, with the most dominant species being Sundstroemia setigera, followed by the cyanobacteria Oscillatoria limosa. Copepoda was the most numerous group of identified zooplankton, followed by tintinnids and foraminiferans. Total suspended solids (TSS) calculations indicated up to nine-fold month-to-month reductions of planktic biomass, observed in the form of diminishing Bacillariophyta (December) and Copepoda (June and December). In conclusion, the studied ponds appear to be suitable for semi-intensive mariculture activity due to the abundance of diverse planktic forms (mainly Copepoda—preferable natural food for commercially important fish species), which was achieved even without the use of fertilizers. However, significant drops of planktic biomass may still occur, which implies the need for regular water monitoring procedures, which would in turn allow fish producers to implement periodical adjustments to the administered feeding rates with artificial diets.