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  • A. nudiventris  (1)
  • Rutilus frisii kutum
  • 2020-2022  (2)
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Year
  • 1
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    Unknown
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25627 | 18721 | 2018-10-07 16:48:29 | 25627 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    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.
    Keywords: Biology ; Iran ; Caspian Sea ; Biology ; Sturgeons ; A. persicus ; A. stellatus ; A. guldenstaedtii ; A. nudiventris ; H. huso ; CPUE
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 98
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  • 2
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    Unknown
    Iranian Fisheries Science Research Institute | Tehran, Iran
    In:  http://aquaticcommons.org/id/eprint/25225 | 18721 | 2018-09-06 05:01:00 | 25225 | Iranian Fisheries Science Research Institute
    Publication Date: 2021-07-16
    Description: The project of Age, growth, feeding regime and fecundity of Kutum (Rutilus frisii Kutum) survey started in south of the Caspian Sea from 2006 to 2007. The aim of project was related to determination of length maturity (Lm50%), identification of feeding animals, and investigation some of biological aspects uncluded in sex ratio, growth and age structure in southern of the Caspian Sea. Total 2706 specimens of Kutum were surveyed. The age structure of Kutum has nine age groups that included in 1, 2, 3, 4, 5, 6, 7, 8, and 9 years. The result showed that maximum frequency was about 39.3 % and were belong to 4 years and minimum frequency which was about o.1 % were belong to 9 years. The maximum and minimum fork length and weight were 58 and 21cm with mean (±SD) 38.4 (± 6.4) cm; 2450 and 104g with mean (±SD) 784.2 (± 383.30) g , respectively. There are significant different between fork length and weight in male and female of Kutum at difference months (ANOVA, P〈0.05). The sex ratio of males to female was 0.65: 1 (males: females). The least and high condition factor was 1.5 in January and 2.17 in October, respectively. Length maturity (Lm50%) was 39.07cm. Minimum and maximum absolute fecundity was varied from 15713 to 130737 eggs with mean (±SD) 69961.7 (± 3836.4). Significant different was between absolute fecundity with fork length and weight (p〈0.05). Gonadosomatic index (GSI) mean for females were 2.5±0.2 (autumn) and 17± 0.2 (spring); 1.2± 0.1 (autumn) and 4.1± 0.2 (spring) for males, respectively wich coincided to spawning period. The highest feeding intensity (Gastrosomatic index) for females was 313.9 ± 65.9 in October and 119.4 ±59.2 in March; 350.7 ±103.7 in October and 144.1±85.04 in March for males, respectively. There are significant different between GSI with male anfemale in difference months (ANOVA, p〈0.05). The Bertalanffy growth equation for all populations of Kutum was L (t) = 63.92[1-e ^0.19 (t (-1.00)]. Main prey mature of Kutum was Cerastoderma lamarki; Gastropoda and Balanus were subordinate, and Crab, Hypanis, Fish (Neogobous sp.) Algae, egg, and scale were random preys. Planktone groups comprise to Exuviaella, Nitzchia, Osillatoria, Synedra, Nematoda, Navicolla, Diatoma, Rholcosphenia were preys juvenile of Kutum. Based on ISI (Important species index), Cerastoderma lamarki and Balanus were dominant species in feeding of Kutum. As a result, growth, fecundity and length maturity of Kutum declined which may due to loss natural breeding area, overfishing (overlapping between fishing and spawning period) and artificial breeding that commenced since 1982. Hopefully, this information can be used in fisheries management.
    Keywords: Aquaculture ; Iran ; Caspian Sea ; Age ; Growth ; Feeding ; Regime ; Reproduction ; Sexual maturity ; Rutilus frisii kutum ; Coastal waters
    Repository Name: AquaDocs
    Type: monograph
    Format: application/pdf
    Format: application/pdf
    Format: 58
    Location Call Number Limitation Availability
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