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A Preliminary Study on The Determination of Reproductive Biology of European Pilchard, Sardina pilchardus (Walbaum, 1792) Distributed in The Aegean Sea Full text
2019
Burcu Taylan | Ertan Taskavak | Sule Gurkan
Sardina pilchardus is a multiple spawning fish, i.e., the species that spawns periodically during the spawning period. In order to examine the reproduction biology of the species, the specimens were obtained in the known spawning period indicated by the current literature obtained from fishers who were commercially fishing in December 2018 and January-February 2019. After the fork length and total length together with their weight measurements, the specimens were dissected in the laboratory. The adult females’ gonads were then fixed in 4% formalin solution for fecundity. A total of 170 individuals was examined and the values of their fork length, total length and weight were computed as 9.7-13.4 cm (mean: 11.16±0.81), 10.5-15 cm (mean: 12.3±0.89), 8.06-23.7 g (mean: 12.7±2.93), respectively. 44 of the supplied specimens were male (25.9%), 122 female (71.8%) and 4 (2.3%) uncertain, thus, the female: male ratio was determined as 2.77:1. According to χ2 test results, a statistically significant difference was observed among individuals. For the specimens examined, the fork length-weight relationship was calculated as W = 0.0098FL2.96, while total length-weight relationship was W = 0.0071TL2.97. In order to calculate the fecundity, sub-samples were taken from the anterior, median and posterior parts of 15 ovaries in the ration of 2 - 5% of the ovary weight and the mature oocytes were counted. As a result, the species’ fecundity was found to be between 4,600-9,800 (6,110±1,755). The relationship between total length and fecundity was computed as W= 1,640.7 TL-13,907 and a linear relationship was determined.
Show more [+] Less [-]A Preliminary Study on The Determination of Reproductive Biology of European Pilchard, Sardina pilchardus (Walbaum, 1792) Distributed in The Aegean Sea Full text
2019
Burcu Taylan | Ertan Taskavak | Sule Gurkan
Sardina pilchardus is a multiple spawning fish, i.e., the species that spawns periodically during the spawning period. In order to examine the reproduction biology of the species, the specimens were obtained in the known spawning period indicated by the current literature obtained from fishers who were commercially fishing in December 2018 and January-February 2019. After the fork length and total length together with their weight measurements, the specimens were dissected in the laboratory. The adult females’ gonads were then fixed in 4% formalin solution for fecundity. A total of 170 individuals was examined and the values of their fork length, total length and weight were computed as 9.7-13.4 cm (mean: 11.16±0.81), 10.5-15 cm (mean: 12.3±0.89), 8.06-23.7 g (mean: 12.7±2.93), respectively. 44 of the supplied specimens were male (25.9%), 122 female (71.8%) and 4 (2.3%) uncertain, thus, the female: male ratio was determined as 2.77:1. According to χ2 test results, a statistically significant difference was observed among individuals. For the specimens examined, the fork length-weight relationship was calculated as W = 0.0098FL2.96, while total length-weight relationship was W = 0.0071TL2.97. In order to calculate the fecundity, sub-samples were taken from the anterior, median and posterior parts of 15 ovaries in the ration of 2 - 5% of the ovary weight and the mature oocytes were counted. As a result, the species’ fecundity was found to be between 4,600-9,800 (6,110±1,755). The relationship between total length and fecundity was computed as W= 1,640.7 TL-13,907 and a linear relationship was determined.
Show more [+] Less [-]A preliminary study of fecundity of whiting, Merlangius merlangus euxinus (Linnaeus, 1758) in coast of Tirebolu (Eastern Black Sea) Full text
2018
Burcu Taylan | Sule Gurkan | Ertan Taskavak | Arzu Aydın Uncumusaoglu
In this research, a preliminary study was carried out in January and February 2014 to determine the fecundity of the whiting species in Tirebolu, Eastern Black Sea. After the total length (cm) and weight (0.01 g) of the 70 fish specimens were measured in the laboratory, they were dissected for sex determination. Using the 20 ovaries at the third and fourth maturation stages, 3 sub-samples which is 2-5% of the total ovary weight (from the anterior, median and posterior parts of the ovary) were taken from each ovary to determine the fecundity, and hydrated oocytes were counted with gravimetric method. Total fecundity, total oocytes number in the ovary were computed with the formula F=(n×G)/g. The total length-weight values were 12.6-23.3 cm (mean 17.08±2.12) and 15.59-95.72 g (mean 41.07 ± 16.75), respectively, and total length-weight relationship was computed as W=0.0073L3.024 (R2=0.94) for the 70 fishes evaluated. Fecundity was computed as 3.247-30.534 (mean: 10.139±6.953) eggs and a linear relationship between fecundity and total length was calculated as F=0.0186L4.5631 (R2=0.70). In conclusion, the fecundity results of this prelaminar study were compared with similar studies on the whiting species from Black Sea and other seas.
Show more [+] Less [-]A preliminary study of fecundity of whiting, Merlangius merlangus euxinus (Linnaeus, 1758) in coast of Tirebolu (Eastern Black Sea) Full text
2018
Burcu Taylan | Sule Gurkan | Ertan Taskavak | Arzu Aydın Uncumusaoglu
In this research, a preliminary study was carried out in January and February 2014 to determine the fecundity of the whiting species in Tirebolu, Eastern Black Sea. After the total length (cm) and weight (0.01 g) of the 70 fish specimens were measured in the laboratory, they were dissected for sex determination. Using the 20 ovaries at the third and fourth maturation stages, 3 sub-samples which is 2-5% of the total ovary weight (from the anterior, median and posterior parts of the ovary) were taken from each ovary to determine the fecundity, and hydrated oocytes were counted with gravimetric method. Total fecundity, total oocytes number in the ovary were computed with the formula F=(n×G)/g. The total length-weight values were 12.6-23.3 cm (mean 17.08±2.12) and 15.59-95.72 g (mean 41.07 ± 16.75), respectively, and total length-weight relationship was computed as W=0.0073L3.024 (R2=0.94) for the 70 fishes evaluated. Fecundity was computed as 3.247-30.534 (mean: 10.139±6.953) eggs and a linear relationship between fecundity and total length was calculated as F=0.0186L4.5631 (R2=0.70). In conclusion, the fecundity results of this prelaminar study were compared with similar studies on the whiting species from Black Sea and other seas.
Show more [+] Less [-]Fecundity of Morocco Dentex Dentex maroccanus Valenciennes, 1830 Distributed in Izmir Bay (Central Aegean Sea of Turkey) Full text
2018
Burcu Taylan | Bahar Bayhan | Oğulcan Heral
In this study, the reproductive properties of the Dentex maroccanus species distributed in the Aegean Sea were determined. A total of 439 fish were collected during the period from December 2012 to March 2014 from the commercial fishers who seasonally hunt in the Foça-Mordoğan region (İzmir, Turkey) were examined. After the measurement of the total lengths and body and gonad weights of the fish samples in the laboratory, their sexes were identified, which revealed that 140 of the samples were male, 206 of the samples were female and 93 of the sample were undeterminated. The female:male ratio was 1.5:1. The 5-point maturity phase discrimination method developed by Holden and Raitt for maturity stages in 1974 was macroscopically examined for female and male fish specimens. A total of 16 ovaries, which were determined to be at the 3rd and 4th stages of maturity according to the method, were used to determine fecundity. The gonadosomatic index values that were calculated based on the seasons revealed that the reproductive period of the species was summer (2.87) and autumn (2.10). The first maturation length for the species was 13.4 cm. Estimates of total fecundity varied between 74252 and 201187 eggs (mean: 123263±44586). There was an exponential relationship between fecundity and total length as F = 10.643L3.111. The diameter of the mature eggs ranged from 0.49 mm to 0.67 mm (mean: 0.59±0.06 mm).
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