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J G Pajuelo - One of the best experts on this subject based on the ideXlab platform.
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Biology of the Sand Smelt, Atherina Presbyter (Teleostei: Atherinidae), Off the Canary Islands (central-east Atlantic)
Environmental Biology of Fishes, 2000Co-Authors: J G Pajuelo, J M LorenzoAbstract:Atherina Presbyter is a common fish off the Canary Islands. Age, growth, reproduction, and mortality of the species are studied based on sampling carried out from July 1995 to June 1996. The parameters of the total length–total weight relationship are: a=0.004521, and b=3.0771. Otoliths age readings indicate that the sampled population consists of four age groups (0–III years). The von Bertalanffy growth parameters for all individuals are: L_∞=122 mm total length, k=0.79 year^−1, and t_0=−0.21 years. Individuals grow quickly in their immature first year, attaining approximately 60% of their maximum length. After the first year, the annual growth rate drops rapidly, because the energy is probably diverted to reproduction. It is a gonochoristic species with no evidence of sexual dimorphism. The gonad is present as a single diffuse testis in males and as a single discrete ovary in females. The overall ratio of males to females is not significantly different from 1:1. The reproductive period of the species is protacted (February to June). The peak of the reproductive effort occurs in April–May. The size at first maturity is 68 mm. The population is being heavily exploited.
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age and growth of the sand smelt atherina hepsetia Presbyter cuvier 1829 in the canary islands central east atlantic
Fisheries Research, 1999Co-Authors: J M Lorenzo, J G PajueloAbstract:Abstract Age and growth of Atherina (Hepsetia) Presbyter off the Canary Islands (Central-east Atlantic) were studied by sampling carried out between July 1995 and June 1996. Individuals ranged in size between 14.5 and 115.5 mm total length, mainly between 25.0 and 70.0 mm. A translucent zone and its adjacent opaque zone were deposited each year on the otoliths. The translucent zone is formed during the winter months, when the temperature of the sea is lowest and the spawning takes place in the species, and the opaque zone during the summer months, when temperature is highest. Fish aged 0–3 year old were found. The von Bertalanffy growth parameters for all individuals are: L ∞ =121.81 mm, k =0.79 year −1 , and t 0 =−0.21 year. Individuals grow fast during the first year of life, attaining approximately 60% of their maximum observed length; after the first year, the annual growth rate drops quickly. The length–frequency analysis provided very satisfactory results and demonstrated the validity of using otoliths for estimating age and growth.
Teresa Moreno Moreno - One of the best experts on this subject based on the ideXlab platform.
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reproductive biology of the sand smelt atherina Presbyter cuvier 1829 pisces atherinidae in the central east atlantic
Fisheries Research, 2005Co-Authors: Teresa Moreno Moreno, J Castro, Juan SocorroAbstract:Abstract This study investigates the reproductive biology of Atherina Presbyter , a fast growing, short-lived coastal pelagic fish found off the Canary Islands. Sampling was carried out monthly between January 1997 and June 1998. The sex of adult fishes ( N = 878) was determined macroscopically and the proportion of males was significantly lower than that of females with a ratio of 1:1.34 males/females. Histological analysis of the ovaries showed the species had non-synchronic oocyte development, and egg-laying occurred in separate batches comprising 20–35% of oocytes. The total length at 50% maturity was 65.4 and 73.1 mm for males and females, respectively. The spawning period occurred predominantly during spring, although a few females were ripe at the beginning of autumn. The average relative fecundity was estimated as per 49.2 eggs/g of fish (S.D. = 22.4) and it depended on the gonad weight which increased with fish length. The relative fecundity was higher in the southern than in the northern and central parts of the distribution area.
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age determination and validation on otoliths of the sand smelt atherina Presbyter cuvier 1829 pisces atherinidae from the central east atlantic
Fisheries Research, 2003Co-Authors: Teresa Moreno Moreno, Beatriz MoralesninAbstract:The technique of reading and interpretation of the daily growth increments (DGIs) in the sagittae otoliths was applied to determine the age and growth parameters of Atherina Presbyter, a characteristic species of the pelagic-coastal system in the central-east Atlantic. Age reading was validated directly by marking otoliths with strontium chloride (SrCl). The results were based on 201 valid readings of monthly samples obtained between June 1990 and December 1991 in coastal waters of the Canary Islands. The analysed specimens ranged in size from 23 to 104 mm total length (TL) and in age between 1 and 15 months. The growth parameters of A. Presbyter were estimated by the fit of the Von Bertalanffy growth function and gave an asymptotic length (L∞) of 106 mm that corresponded to a maximum weight (W∞) of 9.0 g, and a growth constant (k) of 2.511. The maximum size obtained and the duration of the A. Presbyter life cycle in Gran Canaria were estimated as being smaller than those given for this species in more northern latitudes. The size–age relationship estimated in the present study from the daily growth, showed discrepancies with the one obtained in the same study area by other authors using annual mark readings. The annual marks appeared to indicated approximately double the age compared to the daily increments. © 2002 Elsevier Science B.V. All rights reserved.
J M Lorenzo - One of the best experts on this subject based on the ideXlab platform.
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Biology of the Sand Smelt, Atherina Presbyter (Teleostei: Atherinidae), Off the Canary Islands (central-east Atlantic)
Environmental Biology of Fishes, 2000Co-Authors: J G Pajuelo, J M LorenzoAbstract:Atherina Presbyter is a common fish off the Canary Islands. Age, growth, reproduction, and mortality of the species are studied based on sampling carried out from July 1995 to June 1996. The parameters of the total length–total weight relationship are: a=0.004521, and b=3.0771. Otoliths age readings indicate that the sampled population consists of four age groups (0–III years). The von Bertalanffy growth parameters for all individuals are: L_∞=122 mm total length, k=0.79 year^−1, and t_0=−0.21 years. Individuals grow quickly in their immature first year, attaining approximately 60% of their maximum length. After the first year, the annual growth rate drops rapidly, because the energy is probably diverted to reproduction. It is a gonochoristic species with no evidence of sexual dimorphism. The gonad is present as a single diffuse testis in males and as a single discrete ovary in females. The overall ratio of males to females is not significantly different from 1:1. The reproductive period of the species is protacted (February to June). The peak of the reproductive effort occurs in April–May. The size at first maturity is 68 mm. The population is being heavily exploited.
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age and growth of the sand smelt atherina hepsetia Presbyter cuvier 1829 in the canary islands central east atlantic
Fisheries Research, 1999Co-Authors: J M Lorenzo, J G PajueloAbstract:Abstract Age and growth of Atherina (Hepsetia) Presbyter off the Canary Islands (Central-east Atlantic) were studied by sampling carried out between July 1995 and June 1996. Individuals ranged in size between 14.5 and 115.5 mm total length, mainly between 25.0 and 70.0 mm. A translucent zone and its adjacent opaque zone were deposited each year on the otoliths. The translucent zone is formed during the winter months, when the temperature of the sea is lowest and the spawning takes place in the species, and the opaque zone during the summer months, when temperature is highest. Fish aged 0–3 year old were found. The von Bertalanffy growth parameters for all individuals are: L ∞ =121.81 mm, k =0.79 year −1 , and t 0 =−0.21 year. Individuals grow fast during the first year of life, attaining approximately 60% of their maximum observed length; after the first year, the annual growth rate drops quickly. The length–frequency analysis provided very satisfactory results and demonstrated the validity of using otoliths for estimating age and growth.
Beatriz Moralesnin - One of the best experts on this subject based on the ideXlab platform.
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age determination and validation on otoliths of the sand smelt atherina Presbyter cuvier 1829 pisces atherinidae from the central east atlantic
Fisheries Research, 2003Co-Authors: Teresa Moreno Moreno, Beatriz MoralesninAbstract:The technique of reading and interpretation of the daily growth increments (DGIs) in the sagittae otoliths was applied to determine the age and growth parameters of Atherina Presbyter, a characteristic species of the pelagic-coastal system in the central-east Atlantic. Age reading was validated directly by marking otoliths with strontium chloride (SrCl). The results were based on 201 valid readings of monthly samples obtained between June 1990 and December 1991 in coastal waters of the Canary Islands. The analysed specimens ranged in size from 23 to 104 mm total length (TL) and in age between 1 and 15 months. The growth parameters of A. Presbyter were estimated by the fit of the Von Bertalanffy growth function and gave an asymptotic length (L∞) of 106 mm that corresponded to a maximum weight (W∞) of 9.0 g, and a growth constant (k) of 2.511. The maximum size obtained and the duration of the A. Presbyter life cycle in Gran Canaria were estimated as being smaller than those given for this species in more northern latitudes. The size–age relationship estimated in the present study from the daily growth, showed discrepancies with the one obtained in the same study area by other authors using annual mark readings. The annual marks appeared to indicated approximately double the age compared to the daily increments. © 2002 Elsevier Science B.V. All rights reserved.
Juan Socorro - One of the best experts on this subject based on the ideXlab platform.
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reproductive biology of the sand smelt atherina Presbyter cuvier 1829 pisces atherinidae in the central east atlantic
Fisheries Research, 2005Co-Authors: Teresa Moreno Moreno, J Castro, Juan SocorroAbstract:Abstract This study investigates the reproductive biology of Atherina Presbyter , a fast growing, short-lived coastal pelagic fish found off the Canary Islands. Sampling was carried out monthly between January 1997 and June 1998. The sex of adult fishes ( N = 878) was determined macroscopically and the proportion of males was significantly lower than that of females with a ratio of 1:1.34 males/females. Histological analysis of the ovaries showed the species had non-synchronic oocyte development, and egg-laying occurred in separate batches comprising 20–35% of oocytes. The total length at 50% maturity was 65.4 and 73.1 mm for males and females, respectively. The spawning period occurred predominantly during spring, although a few females were ripe at the beginning of autumn. The average relative fecundity was estimated as per 49.2 eggs/g of fish (S.D. = 22.4) and it depended on the gonad weight which increased with fish length. The relative fecundity was higher in the southern than in the northern and central parts of the distribution area.