Age and growth of Boops boops (Linnaeus, 1758) in Izmir Bay,Aegean Sea,Turkey

The present study was conducted to determine the age relationships in lengths and weights of Boops boops (Linneaus, 1756) in Izmir Bay, central Aegean Sea. A total of 932 specimens (503 females and 429 males) were caught by gillnet, trammel net and a combination thereof on a monthly sampling basis from November 2008 through October 2009. Total length and weight of sampled fish ranged from 11.3 to 27.9 cm and from 12.2 to 261.7 g, with a mean of 19.6 cm and 82.7 g, respectively. Length‐weight relationships for all individuals were described by the parameters a = 0.0050, b = 3.237 and r² = 0.956. The von Bertalanffy growth curve fitted to the lengths‐at‐age provided parameters of L_∞ = 29.87 cm k = 0.243 and t_o = ?0.98 for males and L_∞ = 30.79 cm, k = 0.239 and t_o = ?0.90 for females. Based on otolith readings, age determinations varied from 1 to 5 years. Maximum age was 5 years in age group 2, with 29.84 and 37.97% for males and females, respectively. The overall 1 : 1.17 sex ratio of males to females was significantly biased toward females (P < 0.05). There was no statistical difference in the mean condition factor (P > 0.05), with a value of 1.028 for the entire population. The growth performance index (Φ^’) was 2.33 and 2.36 for males and females, respectively. Results were similar to other geographical areas, which suggests that a common fisheries management might be possible.     

Age,growth and reproduction of the black sea bream Spondyliosoma cantharus (Linnaeus, ) (Sparidae) in the Gulf of Annaba (Algeria)

The objective of this study was to determine the basic population‐specific parameters necessary for fish stock assessment in the Gulf of Annaba and to compare these with data from other Mediterranean regions. Black sea bream Spondyliosoma cantharus (Linnaeus, 1758) (N = 501) were collected monthly from January to December 2008 along the Algerian eastern coasts. More than 22 fish were collected each month and ranged in size from 13.4 to 40 cm total length, weighing from 36 to 1080 g eviscerated weight. Biological sampling included weighing and measuring the fish, gonad weighing, sex and maturity stage determination, and age estimation through otolith readings. Validity of the otolith readings for estimating age and growth was supported using the back‐calculation method. Estimated parameters of the von Bertalanffy model are: L_∞ = 33.54 cm, W_∞ = 633.46 g, k = 0.52 year^?1 and t_o = ?0.04 year. The growth performance index (φ) is: 2.76. The length‐weight relationship is: EW = 4.4.10^?6 TL^3.23. The spawning period occurred from February to May, while the gamete emission peaked in April. Females reached sexual maturity at 19.3 cm (2 years) and males at 21.3 cm (3 years). Sexual inversion occurs at approximately 24.3 cm. Spondyliosoma cantharus was characterized as being a protogynic hermaphrodite.     

Testing staining techniques to determine age and growth of Dasyatis pastinaca (Linnaeus, 1758) captured in Iskenderun Bay,northeastern Mediterranean

This study tested the suitability of several staining methods to determine the age of common stingray (Dasyatis pastinaca) from Iskenderun Bay, Turkey. A total of 384 specimens (16.6 cm–69.3 cm disc width) were obtained by trawling between September 2010 and December 2011. Sex ratio of the samples was 53% males and 47% females. Appropriate age determination was firstly demonstrated using Safranin‐O staining. Age readings were made by two independent readers and the index of average percent error (IAPE) determined as 6.3% for Safranin‐O, 6.8% for Crystal Violet, 7.9% for Alcian Blue, and 9.3% for Silver Nitrate. Safranin‐O and Crystal Violet staining methods provided the best results. Verification of temporal growth ring formation was by marginal increment analysis. Disc width–weight relationships were determined by W = 0.0272*DW^3.06 for females and W = 0.0247*DW^3.08 for males. Estimates of the von Bertalanffy growth parameters indicated a larger asymptotic disc width (DW_∞ = 127.06 cm) for females than for males (DW∞ = 114.54 cm); growth parameters were k = 0.058 year^?1, t_o = ?1.508 and k = 0.041 year^?1, t_o = ?3.632 for females and males, respectively.     

Age and growth of the Giant Kelpfish,Heterostichus rostratus Girard 1854, in Southern California,USA

In order to update existing life history parameters, age and growth patterns were determined for Giant Kelpfish, Heterostichus rostratus sampled from nearshore kelp forest and estuary habitats in southern California (USA) from April 2012 through June 2015. Fish were collected by pole spear, beach seine, beam trawl, purse seine, and square enclosure. Using age‐at‐length data derived from otolith readings, Giant Kelpfish were found to have a relatively short life span with the largest examined fish reaching a maximum total length of 413 mm at an age of 5 years. Von Bertalanffy growth parameters estimated for this species were: L_∞ = 45.1 cm, k = 0.25, t₀ = ?0.66. Standard length (SL, cm)‐total length (TL, cm) and total length (TL, cm)‐weight (W, g) relationships were described by the equations: SL = 0.90 TL – 1 and W = 2.21 × 10^?3 TL^3.39, respectively. Wild juvenile Giant Kelpfish collected for this study had a higher growth rate than laboratory‐reared fish from a previous study.     

Length–weight relationship,parameters of growth and mortality for the hardhead halfbeak Chriodorus atherinoides Goode & Bean, 1882 (Beloniformes: Hemiramphidae) from Yucatan Peninsula,Mexico

This study reports length–weight relationships and growth parameters for Chriodorus atherinoides from La Carbonera, a karstic tropical coastal lagoon on the northwestern coast of the Yucatan Peninsula, Mexico. A total of 667 specimens were collected between April 2009 and March 2010. The length‐weight relationship obtained was W = 0.0034Lt^3.22. This study presents the first estimation of the model parameters of the von Bertalanffy growth equation (L_∞ = 27.30 cm, k = 0.76 year^?1 and t₀ = ?0.178 years), the instantaneous total mortality (2.51 year^?1) and the maximum length record (26.0 cm total length), which is greater than previously recorded.     

Age determination and growth estimates of the white‐spotted conger eel,Conger myriaster (Brevoort, 1856) in marine waters of South Korea

The age and growth of conger eel, Conger myriaster, were investigated by measuring transversely sectioned sagittal otoliths samples from 635 individuals. Sample ages ranged from 1 to 13 years in the female data. Parameters of the von Bertalanffy growth function were estimated using nonlinear regression from back‐calculation, mean length of samples at age relationships, and otolith weight‐at‐age relationships. Best‐fitting value of the three methods was the otolith weight‐at‐age relationship (r² = .87). Parameters of otolith weight‐at‐age were estimated as L_∞ = 143.76 cm, K = 0.081, and t₀ = ?1.285. Maximum oocyte diameter (MOD) ranged from 50 to 430 μm. Reproductive traits of ovaries showed a positive relationship between GSI and MOD (r² = .8515). It is suggested that oogenesis begins to develop from 4 years of age and at lengths of about 45 cm TL. In conclusion, these data provide reliable fundamental data for the fish stock management of Conger myriaster in South Korea.     

Population biology of grey gurnard (Eutrigla gurnardus (L.); Triglidae) in the coastal waters of Northwest Wales

The grey gurnard Eutrigla gurnardus (L.) has been identified by ICES as a potential commercial species in the NE Atlantic with recommendations made to derive information on population biology for stock assessment purposes. However, data on the population biology of this species is limited. In this study, data on the age, growth and maturity of grey gurnard were collected by otter trawling in the coastal waters of northwest Wales and Eastern Anglesey. Total length (TL) of fish sampled ranged between 2.1–33.0 cm (male) and 1.9–36.9 cm (female) with the majority of female (70.8%) fish between 11 and 20 cm TL and male fish (70.5%) between 11 and 18 cm TL. The percentage of fish >20 cm TL was larger for females (30.4%) compared to males (17.6%). Total weight (TW) for female and male grey gurnard in the stratified subsample ranged from 1.9 to 499.9 g for females and 2.1–390.0 g for males, with the majority of female (66.3%) and male (76.1%) fish between 10 and 60 g. TL/TW relations for male and female fish and both sexes combined were: TW = 0.006TL^3.07, TW = 0.007TL^3.03 and TW = 0.007TL^3.05 respectively. Age structure (based on otolith reading) ranged between 0.5 and 7.5 years old for females and 0.5 to 5.5 years old for male with the majority of female (41.7%) and male (46.0%) fish aged as 1.5 years old. The age structure of female and male grey gurnards was significantly different with the majority of older fish (>2.5 years) being female. The von Bertalanffy growth functions were calculated as L_t = 32.4[1 ? e^{?0.24(t + 1.41)}] for males, L_t = 45.9[1 ? e^{?0.16(t + 1.37)}] for females and L_t = 44.0[1 ? e^{?0.18(t + 1.20)}] for both sexes combined. Instantaneous rates of total mortality were similar for males and females and the combined Z value 1.00 year^?1 with the natural mortality rate estimated as 0.33 year^?1. The size at 50% maturity (L₅₀) was estimated to be 25.3 cm TL for males, females and for both sexes combined. Age at 50% maturity (A₅₀) was 3.2 years for both males and females. The results of this study provide the first information on the population biology of E. gurnardus in the Irish Sea, the first detailed study in the NE Atlantic since 1985 and helps to address the data gap identified by ICES in knowledge of the population biology of this species.     

Reproduction,growth and mortality of the exploited sillaginid,Sillago ciliata Cuvier, 1829

The goal of this study was to examine the age and size composition, growth, reproductive biology and mortality of Sillago ciliata Cuvier, 1829 in one of the largest estuarine commercial fisheries in south‐eastern Australia. The study also aimed to present a qualitative comparison of latitudinal variations in some of these characteristics along the eastern Australian coastline. The sampled population contained fish aged up to 10 years with a maximum size of 39.2 cm fork length (L_F), and was dominated by 1–5 year olds. Sexual divergence in both the age and size structure of the population was recorded. Female S. ciliata grew slightly faster and attained a greater maximum size (L_∞ = 33.79 cm L_F, k = 0.50 year^?1 and t₀ = ?0.57 years) than males (L_∞ = 29.73 cm L_F, k = 0.49 year^?1 and t₀ = ?0.67 years). Females also matured at a significantly larger size (19.13 cm) and older age (1.63 years) than males (size: 17.07 cm, age: 1.10 years). Reproductive activity was highest between September and March. There were no differences between males and females in terms of mortality rate; the estimated total population, natural and fishing mortality rates were Z = 0.64, M = 0.42 and F = 0.22, respectively. Although these mortality rates suggest that S. ciliata in the Clarence River are relatively resilient to current rates of exploitation, regular monitoring of their commercial and recreational catch as well as their population structure is recommended in order to maintain sustainable fisheries. Potential latitudinal shifts in the spawning period, age structure and growth of S. ciliata along eastern Australia were also revealed.     

Age,growth, reproduction and feeding of John Dory,Zeus faber (Pisces: Zeidae), in the Saros Bay (North Aegean Sea)

The age, growth, reproduction, sexual maturity and stomach content of John Dory (Zeus faber), caught in the Bay of Saros (North Aegean Sea) between September 2006 and September 2008, were investigated. The female‐male ratio was 1.6 : 1. The total length of females ranged from 13.8 cm to 52.8 cm, and of males from 12.2 cm to 42.9 cm. The length‐weight relationship was W = 0.0174*L^2.936. Age data derived from vertebral centra readings were used to estimate the growth parameters of the von Bertalanffy equation. Growth parameters for females were L_∞ = 58.50 cm K = 0.11 year^?1, t₀ = ?0.99 year and for males L_∞ = 45.01 cm, K = 0.13 year^?1, t₀ = ?1.17 year. Maximum age was 18 years for females and 17 years for males. Length at first maturity for both females and males was 25.4 cm. Monthly values of the gonadosomatic index indicated that spawning occurred mainly in two peaks: one between January and June, and the other from August to September. Stomach content analysis showed the most‐preferred prey to be Pisces (IRI% 97.3).     

Age and growth of the hollowsnout grenadier, Caelorinchus caelorhincus (Risso, 1810), in the Aegean Sea

Age and growth of the hollowsnout grenadier was studied based on samples collected seasonally in the Agean Sea between March 2003 and January 2004. Total length ranged from 9.0 to 21.6 cm. Length–weight relationship was described as a = 0.0032, and b = 3.008. Age determinations based on otolith readings were between 1 and 10 years. The von Bertalanffy growth curve fitted to observed lengths‐at‐age provided parameters of L_∞ = 24.9 cm, k = 0.115 and t_o = ?3.494.     

Identifying growth parameters for two endemic species [Capoeta antalyensis (Battalgil, 1943) and Pseudophoxinus antalyae Bogutskaya, 1992] in Duden Creek,Antalya, Turkey

It is hypothesized that Capoeta antalyensis (Battalgil, 1943) and Pseudophoxinus antalyae (Bogutskaya, 1992) might display specific growth characteristics that differ from other species of their genus. Age and growth were described for species from Duden Creek (Antalya, Turkey) from February 2008 to January 2009. The length–weight relationship for all individuals were described by the parameters: a = 0.0143 and b = 2.946 for C. antalyensis and a = 0.0084 and b = 3.251 for P. antalyae. The von Bertalanffy growth parameters based on data from scales were L∞ = 35.78 cm, k = 0.251 year^?1 and t₀ = ?0.30 for C. antalyensis and L∞ = 22.59 cm, k = 0.232 year^?1 and t₀ = ?0.78 for P. antalyae. The growth characteristics for these two species are not much different from those of closely related species from the same genus.     

Length–weight relationship and parameters of growth for the checkered puffer Sphoeroides testudineus from a karstic tropical coastal lagoon: La Carbonera,Yucatan, Mexico

This study reports length–weight relationships and growth parameters for Sphoeorides testudineus from La Carbonera, a karstic tropical coastal lagoon on the northwestern coast of the Yucatan Peninsula, Mexico. A total of 461 specimens were collected between April 2009 and March 2010. The length–weight relationship was W = 0.061Lt^2.98. Model parameters of the von Bertalanffy growth equation were: L_∞ = 29.50 cm, k = 0.77 year^?1 and t₀ = ?0.168 years.     

Population biology and vulnerability to fishing of deep‐water Eteline snappers

Deep‐water fish in the tropical and sub‐tropical Pacific Ocean have supported important fisheries for many generations. Observations of localised depletions in some fisheries have raised concerns about the sustainability of current fishing rates. However, quantitative assessments of deep‐water stocks in the Pacific region have been limited by the lack of adequate biological and fisheries data. Estimates are provided of age‐based demographic parameters for two important deep‐water snapper species in the Pacific, Etelis carbunculus and E. coruscans. A spawner biomass‐per‐recruit (SPR) model was applied to determine fishing mortality rates for each species that would achieve specified biological targets (40% unexploited levels, SPR₄₀) and limit (30% unexploited levels, SPR₃₀) reference points, and examine the sensitivity of the model to variation in natural mortality and age at first capture. The maximum observed age, based on increment counts from sectioned otoliths, was 21 years for E. carbunculus and 18 years for E. coruscans. Total mortality (Z), estimated from the Hoenig regression, was 0.21 year^?1 for E. carbunculus and 0.25 year^?1 for E. coruscans. The best approximating growth models were the von Bertalanffy model (L_∞ = 896 mm fork length, k = 0.28, t₀ = 0.51) for E. carbunculus and the logistic model (L_∞ = 879 mm fork length, k = 0.32 year^?1, t₀ = 3.42) for E. coruscans. The spawner biomass‐per‐recruit analysis demonstrated that lower rates of fishing mortality were required for E. coruscans than for E. carbunculus to maintain spawning biomass above estimated biological reference points. Estimates of spawner biomass‐per‐recruit were more sensitive to variation in natural mortality than in the age at first capture, suggesting that regulating fishing mortality rather than gear selectivity would be a more effective management measure for both species. Maintaining fishing mortality <0.1 for both species is recommended as a cautious approach to management, given the uncertainty in estimates of natural mortality and mixed fishery considerations.     

Age,growth and mortality of Lutjanus alexandrei in estuarine and coastal waters of the tropical south‐western Atlantic

Otolith‐based methods were used to determine life history traits of the endemic Brazilian snapper (Lutjanus alexandrei) in estuarine and coastal environments in the south‐western Atlantic. Fishes were caught as juveniles inside mangrove‐bordered estuaries by traditional corral fisheries whereas adults were captured at sea using motorboats with trap and gill nets. Fish were sampled during landings and 331 otolith pairs were extracted from L. alexandrei. Inshore mangroves comprised individuals of 0–4 years (mean: 2 years), while individuals in deeper reef environments were older (range: 3–22; mean: 8 years), indicating an ontogenetic shift at approximately age 3 or 4. Edge analysis was used to validate the annual deposition in the otoliths, suggesting that opaque growth rings were formed between April and September. Age‐at‐length data were used to predict L. alexandrei growth rates using the von Bertalanffy growth model from where the parameters were calculated: L_∞ = 31 cm, k = 0.24, t₀ = ?1.26, r² = 0.97. Mortality rates were estimated for coastal habitats, with Z = 0.22 and S = 0.78 year^?1, based on ages 7–17. Additionally, evidence of ontogenetic migration is provided by age and size structure.     

Age,growth and maturity of tub gurnard (Chelidonichthys lucerna Linnaeus 1758; Triglidae) in the inshore coastal waters of Northwest Wales,UK

The tub gurnard Chelidonichthys lucerna has been identified by ICES as a potential commercial species in the northeast Atlantic with recommendations made to monitor landings and discards and to derive information on population biology for stock assessment purposes, however, data are lacking for the species in the northeast Atlantic. Therefore, aims of this study were to provide data on the size/age‐structure and patterns of growth, maturity and mortality of C. lucerna in Northwest Wales, UK, and in doing so to provide data on the biological characteristics of the most northerly population studied to date for comparison with the existing data for southerly Mediterranean populations. Data on the age, growth and maturity of C. lucerna were collected by otter trawling (73 mm cod‐end stretched mesh size) in the coastal waters of Northwest Wales, UK in October (2000–2011, excluding 2006). Total length (TL) of fish sampled ranged between 10.5–41.0 cm (males) and 10.4–57.5 cm (females). The majority of the female fish were between 20–30 cm TL (60.2%) and the majority of the male fish between 20–30 cm TL (58.3%) respectively. TL/weight (W) relations for male and female fish were similar and the combined data was described by W = 0.0067 TL^3.10. Age of fish ranged between 1–7 years old for female fish and 1–5 years old for male fish respectively with the majority of female fish 3 years old (40%) and the majority of male fish 3 years old (37%). The age structures of female and male tub gurnards were not significantly different with the older age classes consisting predominantly of female fish. Both males and females exhibited similar asymptotic growth patterns and the combined von Bertalanffy growth function was TL_t = 51.6 (1 ? e ^{[?0.25(t + 0.41)]}). Instantaneous rates of total mortality were calculated as 1.04 year^?1 for males and 1.11 year^?1 for females. The size (L₅₀) and age at first maturity (A₅₀) were estimated to be 29.1 cm TL and 2.8 years for males, 27.7 cm TL and 2.7 years for females and 28.0 cm TL and 2.8 years for both sexes combined. The results of this study provide the first information on the biology and population dynamics of C. lucerna in the Irish Sea, the first data collected in the northeast Atlantic since 1985 and the most northerly population studied to date.     

Reproduction,growth and feeding habits of stout beardfish Polymixia nobilis (Polymixiidae) off the Canary Islands (NE Atlantic)

The present study provides fisheries biology knowledge which will allow the implementation of regulatory measures contributing to the sustainability of the fisheries and the conservation of the stout beardfish Polymixia nobilis Lowe, 1838 off the Canary Islands, north eastern Atlantic Ocean. Males ranged between 16.5 and 38.4 cm fork length (FL) and females from 14.2 to 46.5 cm FL. Sex ratio by size classes provided significant differences in classes higher than 36 cm, being clearly unbalanced in favour of females. Individuals in maturing and mature stages were present during all months sampled, although a spawning peak is evident between April and June. Size at first maturity was estimated as 26 cm FL for females and 30 cm FL for males. Age was determined from annuli in whole otoliths. Age range was found to be 0–14 years for fish measuring 14.2 to 46.5 cm FL. It is a slow‐growing and long‐lived species. Significant differences in the growth parameters between sexes were detected. The von Bertalanffy growth parameters estimated for females (n = 213) were L_∞ = 45.92 cm LF, k = 0.16 years^?1 and t₀ = ?2.84 years; and for males (n = 186) L_∞ = 36.44 cm LF, k = 0.26 years^?1 and t₀ = ?2.16 years. Stomach analysis indicated some variations in the feeding habits with growth: individuals of small and medium sizes preyed on crustaceans and fishes, while large specimens preyed mainly on fishes.     

The relationship between otolith size and estimated age of tigertooth croaker (Otolithes ruber Bloch and Schneider, 1801) in Oman Sea,Iran

The relationships between somatic growth and otolith dimensions, otolith size to estimated age and growth parameters of the tigertooth croaker (Otolithes ruber) were investigated in 100 specimens (size range: 19.1–52.0 cm, total length) from the Oman Sea area, September 2014. All 100 otoliths were sectioned and determined by age. The oldest specimen was a 4.5‐year‐old female with a total length of 40.6 cm; the youngest specimen was also a female estimated at 1 year of age with a total length of 19.1 cm. The von Bertalanffy growth equation was estimated as L_t = 54.70 (1 ? exp (?0.37 (t + 0.21))). Concluded was that there is a significant relationship between body size, otolith dimensions and estimated age of Otolithes ruber.     

Life‐history traits of Aphanius danfordii (Boulenger, 1890) (Pisces: Cyprinodontidae), endemic to Kızılırmak Basin (Turkey)

The life‐history traits of Aphanius danfordii in Hirfanl? Reservoir were studied on the basis of 2252 specimens caught between April 2008 and April 2009. Maximum age was determined as five years for both sexes. The overall sex ratio of males to females was 1 : 1.21; however, this ratio varied by age and season. Mean total length at age data derived from scale readings were used to estimate growth. The von Bertalanffy growth parameters were: L_∞ = 126.63 mm, K = ?0.09, t₀ = 2.35 for females; and L_∞ = 61.2 mm, K = ?0.19, t₀ = 2.76 for males. The gonadosomatic index (GSI) values indicated spawning to be from May to September. Absolute fecundity varied from a minimum of 143 eggs for age one to a maximum of 698 eggs for age five. Relationships between fecundity–length and fecundity–weight were described by the equations: F = 0.0002 TL^3.3222 and F = 36.032 W^1.0053, respectively. The equation of the relation between absolute fecundity and age was F = 25.372 t^1.2343.     

Age and growth characteristics of Schizopygopsis younghusbandi Regan, 1905 in the Yarlung Tsangpo River in Tibet,China

To better understand the biology of Schizopygopsis younghusbandi Regan, 1905 and its relationship with management considerations, this study describes the relationships between otolith size and fish length and age, verifies annual periodicity of otolith annulus formation, and estimates the S. younghusbandi growth parameters. These age and growth characteristics were studied using 694 specimens collected from August 2008 to August 2009. Otoliths grew asymmetrically throughout the range of standard length (SL) studied, showing a clear pattern of alternating translucent and opaque bands. Marginal increment ration (MIR) analysis of specimens up to 6 years of age indicated that one opaque band and one translucent band were laid down each year. Maximum observed age was 17 years, corresponding to a female of 35.8 cm SL and 589.1 g body weight (BW). The SL‐BW relationship was described as BW = 1.122 × 10^?5 SL^3.030 for sexes combined. The von Bertalanffy growth function was used to model back‐calculated lengths as L_t = 338.4 (1?e^{?0.233 (t + 0.403)}) for males, and L_t = 433.9 (1?e^{?0.194 (t + 0.397)}) for females. Growth performance of S. younghusbandi was relatively higher than those of other Schizothoracinaes inhabiting the same river.     

Population parameters of stargazer (Uranoscopus scaber Linnaeus, 1758) in the southeastern Black Sea region during the 2011–2012 fishing season

The population parameters of stargazer (Uranoscopus scaber Linnaeus, 1758) were studied regarding age composition, sex ratio, growth, survival and mortality rates, and the exploitation rate in the southeastern Black Sea near the coast of Turkey during the 2011–2012 fishing season. According to ageing analysis of the samples, age group 1 is the most abundant (47.76%), followed by age 2 (41.04%), age 3 (9.33%), age 0 (1.12%) and age 4 (0.75%). Mean totals as well as total lengths and weights for males and females were 14.5 ± 0.22 cm and 12.9 ± 0.19 g, 16.6 ± 0.24 cm and 62.1 ± 2.76 g, and 37.2 ± 1.92 cm and 87.1 ± 3.88 g, respectively. The mean condition factor was K = 0.0167, while the sex ratio was 53.98% female, 38.75% male and 7.27% immature. Length‐weight, age‐length and age‐weight equations were W = 0.014 × L^3.059, L_(t)=44.5*[1?e^{?0.148*(t +1.242)}] and W_(t)=1544.4*[1?e^{?0.148*(t + 1.242)}]^3.059, respectively. The computed survival rate (S), instantaneous total mortality rate (Z), annual mortality rate (A), natural mortality rate (M) and fishing mortality rate (F) were S = 28.94%, Z = 1.24 year^?1, A = 71.06%, M = 0.26 year^?1 and F = 0.98 year^?1, respectively. The exploitation rate was 0.79, which is above the optimum exploitation levels.