Artificial propagation and Culture of Rutilus frisii kutum of Autumn form for restocking

The Kutum, Rutilus frisii kutum, is one of the most important bony fishes in Iranian coastal of Caspian Sea. Its harvest range is between 9000-10000 tons in a year, nearly 60% of the income of Bony fish fishery produced by kutum fishery. The stock of this species reduced drastically in 1982 and the catch slumped to the less than 250 tons in a year. Kutum spawning grounds deterioration, illegal catch, and lack of restocking program were the main cause of the decline. This Spices in nature comprised by two distinct form, autumn and spring form. It is worth to be mentioned, by the effect of Caspian Sea Bony fishes Research Center s experts in 1983, artificial spawning and releasing the fries to the sea were commenced and the catch steadily improved. But all activities concerning restocking of kutum concentrated in spring form, as at present about 260 million its fries are released into sea for restocking by Iranian Fisheries Organization, but for above reasons and lack of restocking program, the populations of autumn form gravely shrinked and neared to be extinct. Therefore, to enhance the biodiversity and boost fishers livelihood of kutum in Caspian Sea this project implemented by cooperation of Iranian Fisheries Organization (IFRO) and Caspian Environment Program (CEP) in Aquaculture Institute (Inland Waters). In this project, brooders caught from Anzali lagoon and maintained in two different condition, include of floating cages in Anzali lagoon and earthen ponds in Sefidrud Fisheries Research Station. The results showed that there weren’t significant differences between two maintenance statuses in maturation period and other reproductive characteristics of brooders. The ratio of male to female was 1 to 1.4. Minimum and maximum weight measured 1450 to 3100 g (with average of 1850 g) in female and 670 to 1900 g (with average of 1165 g) in male, respectively. The first natural spawning of brooders occurred in the end of January in temperature of 8 till 10 °C in concrete ponds. Also, some of maintained brooders in earthen ponds spawned in February. The average number of absolute, function and relative fecundity determined 88565 16809, 73805 14008 and 48670 12056, respectively. For artificial spawning, male and female brooders injected by pituitary gland with dose of 2-3 and 4-5 mg/kg body weight, respectively. Approximately, 10 and 8 present of female were over-ripe and immature in March (artificial spawning time), respectively. More than 59 % of injected female brooders induced to spawning in first stage after 10-12 hours and 13 % of them in twice stage and 7-8 hours after first stage. And also, 27.6% of females didn’t positive response to injection. Dry method used for eggs fecundity and incubation period lasted 7- 10 days in 14-16 °C. In totally, eggs fertilization were more than 95% and the average of eggs fertilization percent in throughout of period measured more than 92.7 6 %. Eyed eggs appearance occurred 3 days after fecundity and its mean was 92.7 15.1%. Larvae after yolk sac absorption feed with dry milk for 4-5 days and then introduced into fertilized earthen ponds (500 m2 and equipped to aerators) in intensive condition and fed with micro pellet food for 3-4 month. In finally, more than 1.8 million fries of 1-2 g and some more than 5 g produced and released into Anzali lagoon to its restocking for first time. It is expected that continuing of restocking process of autumn form kutum by Iranian Fisheries Organization eventuate to population increasing of this form in Caspian Sea in future

Determination of optimum dosage of Ovaprim injectionon artificial spawning efficiency of Esox lucius

This project was conducted to goal of optimum dosage determination of ovaprim injection to artificial spawning efficiency of Esox lucius. The research implemented by 4 treatments with 3 replicates for each ones. 3 female and 6 male brooders injected in each replicate. The animals in 1, 2 and 3 treatments injected by 10, 20 and 30 µg/kg BW, respectively, and 4th treatment as a control injected with 4 mg/kg BW pituitary gland extract. Average weight of brooders were 1361±521, 1376±954, 1009±160 and 1100 ±422 g in 1, 2, 3 and 4 treatments in females and 689±145, 734±197, 547±118 and 794±238 g in males, respectively. In addition, positive response percent to hormone injection were measured 77.8 ±19.24 , 88.9 ± 19.24 , 55.5 ±50.91 and 55.5 ± 19.24 % in 1, 2, 3 and 4 treatments in female and 94.4 ± 9.58, 88.9 ±19.26 , 83.3±28.86 and 88.9 ± 19.26 % in male brooders, respectively, but there was no significant different between all of treatments (p<0.05). Incubation period from fertilization till hatching step in 7 to 15 ˚C was 5 to 10 days with average of 7±1.5 days. Fertilization content was in 1 to 4 treatments measured 87.1±10, 88.04±7.7, 83.9±5.2 and 72.4±19.7 %, respectively and also the treatments didn’t show any different significantly together (p<0.05). Average percentage of eyed eggs 66.6±15.9 in treat 1, 61.2±22.3 in treat 2, 58.3±10.7 in treat 3 and 56.1±15.04 in treat 4, without any significant different between of them (p<0.05). Hatching of eggs mean were measured 27.41±19.8 in treat 1, 39.53±26.9 in treat 2, 95.18±5.6 in treat 3 and 26.78±12.4 in treat 4, and significant different observed between of them too (p<0.05).In the other hand, mean percent of larvae with active feeding in these treatments were measured 18.77±14.6, 20.1±8.51, 55.6±11.6 and 14.51±7.72 as the treatments had significant different (p<0.05). Also, the best temperature and dosage injection of ovaprim hormone was 9 to 12.5 ˚C and 20µg/kg BW, respectively. The end of trial, from 103740 larvae introduced to earthen pond obtained 8000 fingerlings with weight of 2.68±0.6 g and length of 6.96±0.51 cm

Experiments on polyculture of pike, Esox lucius, with carps

The Goal of project implementation was survey of biological roles of Northern pike, Esox lucius, in decreasing of Coarse fish and other un economics organisms in carps ponds and also increasing of final crops in hectare and determination of Suitable ration of pike in ponds. This project implemented by 5 treatment with 3 replicates for every ones in 2 years. The pike density was 200, 350, 500 and 650 fish individuals per hectare for 1, 2, 3 and 4 treatment, respectively, and fifth treatment was without pike. The treatments of 1 and 3 conducted in first year and other in second year of test period. At first, about 26 brooders Caught from Anzali Lagoon, and reproduced by artificial and semi - natural methods in Sefidroud Fisheries Research Station in 12–14 °c temperature. Produced larvae reared in earthen ponds and fries reached to weight of 10 -12 g after 45 days. Mean weight, length and survival rates of fish was 12.27 and 32.5 g, 11.44 and 15.83 cm, and 40 and 21% after 45 and 60 days, respectively. The carp density in ponds was 3500 fish individuals per hectare and stocking rates were 55 % silver carp, 20 % common carp, 10 % bighead carp and 15 % grass carp. In throughout of the experiment period, physico– chemical factors measured and plankton (phyto and zoo), benthos, un wanted fish and other organisms investigated. The biomass of unwanted fishes reduced to 76/81 and 60/6 % in first and second year of experiments respectively. The results showed that Esox lucius had effect in increasing of objective fish produce about 17.9 % and 3.9 % in first and second period of project implementation respectively. The average of fish produce in pond unit (2400 m^2)was 842 kg (3508 kg/ha ), 825 kg (3439 kg/ha) and 776 kg (3232 kg/ha) in first , second and control treatments first year of test period , and also in second year was 865 kg (3603 kg/ha), 877 kg (3652 kg/ha) and 848 kg (3531 kg/ha) in second , fourth and control treatments , respectively. A significant different found in final weight mean of common carp between treatments and Control ponds (P <0/05), as the weight of common carp in treatments ponds was 220 % in first year and 191 % in second year more than control pond. In end of the trial, the mean weight of Esox lucius was 265 ± 74, 276 ± 104, 159 ± 33 and 265 ± 89 g in 1, 2, 3 and 4 treatment, respectively. Survival rate of Northern pike in 1 to 4 treatment was 43.8, 55.2, 40 and 35.6 %, respectively