ALBERT

Description: The present study that was conducted in collaboration with the departments of fish breeding and rearing, pathology and stock assessment of the International Sturgeon Research Institute at the Shahid Beheshti hatchery commenced on 26 February 2002 and ended on 7 June 2002 simultaneously with the breeding of beluga breeders. About 230 sturgeon specimens were studied of which 176 belonged to A. persicus spawners (103 females used for artificial breeding, 16 females not used for artificial breeding and 57 males), 46 A. stellatus spawners (13 females used for artificial breeding, 20 females not used for artificial breeding and 13 males), 3 A. nudiventris spawners and five H. huso female spawners. The total length of A. persicus spawners used for artificial breeding ranged from 131.5 to 211 cm with an average length of 172.5 cm and their weight ranged from 14 to 49 Kg. The minimum and maximum weight of eggs was 9 and 1.5 Kg, respectively and the minimum and maximum number of eggs per gram was 46 and 67 eggs, respectively. The maximum condition factor for spawners was 0.94 and the minimum condition factor was 0.49 (average 0.74). The age of spawners ranged from 12 to 20 years and the minimum and maximum time taken by spawners to respond to breeding was 293.8 and 486 t?. The GV1 in these breeders ranged from 6.2 to 17.5 and GV2 ranged from 5.3 to 9.3. The maximum fertilization rate was 100 %. The total length of A. persicus breeders that were not used in artificial breeding ranged from 152 to 203 cm and their weight ranged from 14 to 46 Kg. The minimum and maximum weight of eggs was 3.2 and 8.5 Kg, respectively and the minimum and maximum number of eggs per gram was 46 and 64 eggs, respectively. The maximum condition factor for spawners was 0.81 and the minimum condition factor was 0.39 (average 0.69). The age of spawners ranged from 16 to 19 years. The GV1 in these breeders ranged from 7.8 to 16.3 and GV2 ranged from 6.5 to 8.2. Total length of male A. persicus breeders ranged from 129 to 178 cm and their weight ranged from 7 to 25.5 Kg. The maximum age of these breeders was 17 years and their minimum age was 11 years. The condition factor in these breeders ranged from 0.33 to 0.84. In A. stellatus breeders total length ranged from 128.5 to 163 cm and weight ranged from 7 to 14.5 Kg. The minimum and maximum weight of eggs was 1 and 2.7 Kg, respectively and the minimum and maximum number of eggs per gram was 67 and 129 eggs, respectively. The maximum condition factor for spawners was 0.58 and the minimum condition factor was 0.37 (average 0.48). The age of spawners ranged from 10 to 16 years and the minimum and maximum time taken by spawners to respond to breeding was 276.8 and 737.3 t?. The GV1 in these breeders ranged from 9.1 to16.2 and GV2 ranged from 3.64 to11. The maximum fertilization rate was 90 %. The total length of A. stellatus breeders that were not used in artificial breeding ranged from 129.5 to 165.5 cm and their weight ranged from 7.3 to 17 Kg. The minimum and maximum weight of eggs was 1.2 and 3 Kg, respectively and the minimum and maximum number of eggs per gram was 71 and 124 eggs, respectively. The maximum condition factor for spawners was 0.76 and the minimum condition factor was 0.39 (average 0.51). The age of spawners ranged from 8 to 14 years. Statistical analysis of data recorded other than GV showed no significant differences between the parameters measured in A. persicus breeders used for artificial breeding and those not used in artificial breeding. Considering the importance of the pathological state of spawners used for breeding the frequency and cause for mortality in incubators as well as vniro tanks and so also the condition of sturgeon fry in earthen ponds in terms of bacterial and parasitical infection and the effects of these infections on survival rate and growth of fry and the quality control of spawners and fry were carried out in the Shahid Beheshti and Yousefpour hatcheries. The 149 sturgeon breeders studied (109 A. persicus, 36 A. stellatus, 3 A. nudiventris and 1 H. huso) at the Shahid Beheshti hatchery showed 8 kinds of parasitical worms. The results obtained from this study indicate that A. stellatus breeders showed the maximum number of digestive tract parasitical worms. Cucullanus spherorocephalus with a prevalence rate of 84.26 % showed the highest abundance and Corynosoma strumosum and Eubothrium asipenserinum with a prevalence rate of 0.93 % showed the minimum abundance in A. persicus spawners. On the basis of this study the digestive tract parasite Skrjabinopsolus semiarmatus with a prevalence rate of 77.78 % showed the maximum abundance and Amphilina foliacea and Eustrongylides excisus with a prevalence rate of 2.78 % showed the minimum abundance in A. stellatus spawners. The relationship between weight of spawners and weight of eggs harvested was studied with prevalence of digestive tract parasites. No parasitical and bacterial infection was observed in the 100 sturgeon larvae examined. Examination of sturgeon fingerings in the two hatcheries in the middle and again at the end of the rearing period showed no signs of bacterial and fungal infections. In the parasitical examination of sturgeon fingerlings studied Triclodina and Diplostomum were identified. Percentage incidences of Diplostomum in the Shahid Beheshti hatchery was 4.97 % and that in the Dr. Yousefpour hatchery was 10.09 %. The percentage incidences of Triclodina in the Shahid Beheshti and Yousefpour hatcheries were 46.68 % and 70.76 %, respectively. However no Diplostomum infections were observed in the 113 A. stellatus specimens examined in the Shahid Beheshti hatchery. Results obtained from this study indicate that A. stellatus specimens from the Dr. Yousefpour hatchery showed higher prevalence to Triclodina as well as Diplostomum infection as compared to the A. stellatus studied in the Shahid Beheshti hatchery. Monitoring the hygienic conditions in the two hatcheris under study during mid-rearing period and at the end of the rearing period revealed an increase in prevalence rate and intensity of Triclodina and Diplostomum infection at the end of the rearing period. Examination of pectoral fin of sturgeon fingerlings indicated higher incidences of pectoral fin deformities in fingerlings studied in the Shahid Beheshti hatchery than in the Dr. Yousefpour hatchery. In 2002 release of fingerlings started on 15.06.2002 at the Shahid Beheshti hatchery and on 8.9.2002 at the Dr. Yousefpour hatchery. Totally 4809554 fingerlings were released into the Sepidrud River. Totally 2889462 fingerlings were released from 31 earthen ponds (2 hectares) at the Shahid Beheshti hatchery starting from 17.6 2002 to 21.7.2002 out of which 2563159 fingerlings belonged to A. persicus that comprised 88.7 % of the total abundance with a mean weight of 5 g and mean length of 10.9 cm, 324789 fingerlings belonged to A. stellatus that comprised 11.2 % of the total abundance with a mean weight of 6.9 g and mean length of 16.2 cm, 1514 fingerlings belonged to A. nudiventris comprising 0.1 % of the total abundance with a mean weight of 12.9 g and a mean length of 14.5 cm. Out of the total number of fingerlings released 74.5 % of A. persicus, 98 % of A. stellatus and 100 % of A. nudiventris were above 3 g per fish in weight. The survival rate of reared fishes was 45.47 % for A. persicus 0.89 % for A. nudiventris. As the exact number of A. stellatus larvae introduced to the rearing ponds was not known the survival rate for this species was not estimated. In A. persicus specific growth rate (3.36) was very low while condition factor (0.41) was moderate. In A. nudiventris growth rate (3.37) and condition factor (0.41) were moderate. About 1920092 fingerlings were released from the Dr. Yousefpour hatchery starting from 15.06.2003 to 08.09.2003 of which 1895948 fingerlings belonged to A. persicus that comprised 98.8 % of the total number with a mean weight of 3.4 g and a mean length of 9.4 cm, 24144 fingerlings belonged to A. stellatus comprising 1.3 % of the total number with a mean weight of 7.5 g and a mean length of 11.7 cm Out of the total number of fingerlings released 43.7 % of A. persicus and 31.7 % of A. stellatus fingerlings were above 3 g per fish in weight. The survival rates of the reared fishes were 24.2 % for A. persicus and 14.6 % for A. stellatus. In A. persicus the growth rate (2.99) was low while condition factor (0.38) was moderate. In A. stellatus the growth rate (3.06) and condition factor (0.30) were low. Significant differences (P〈0.05) were observed on comparing condition factor (F=4.573), survival rates (F=20.971) and rearing period (F=5.038) in A. persicus in the two hatcheries. Therefore A. persicus fingerlings released from the Shahid Beheshti hatchery showed better survival rates and attained the maximum mean weights in a shorter rearing period, whereas fingerlings released from Dr. Yousefpour hatchery were in a better state regarding condition factor.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9%, respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only.

Description: This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9% , respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only.

Description: Iranian Fisheries Science Research Institute

Description: Published