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1.
The present study validates age estimates from a suite of calcified structures (scales, opercular bones and otoliths), assesses the consistency of age interpretations and evaluates growth models in common carp from the lower Murray River, Australia. Marginal increment analysis was used to validate annulus counts, with attention to the 'edge interpretation problem'. The formation of annuli occurred annually after pooling annulus groups, and in carp 4 and 5 years old. The regular alternation of opaque and translucent zones in opercular bones and whole otoliths of younger and older carp was also suggestive of annual periodicity. From systematic comparisons, the use of both opercular bones and whole otoliths in routine age determinations is recommended. Six growth models, including the von Bertalanffy growth function (VBGF) and five polynomial curves were tested to describe growth in length. A log-log quadratic function, by virtue of its precision, and the VBGF, with wider applicability and more biological realism, were chosen.  相似文献   

2.
Totals of 284 Hemigrammocapoeta kemali specimens were caught during 1998 in the I??kl? Lake, Turkey. Their ages, lengths and weights were determined to estimate length–weight relationships and age composition. Fecundity and oocyte diameter were also determined. The sex ratio was 1 : 1.29. Fork length and total weight of specimens ranged from 3.4 to 8.2 cm and from 0.5 to 6.9 g, respectively. Maximum age observed was 4 years. The length–weight relationship for all fish was best described by the equation W = 0.0121*L3.06; the von Bertalanffy growth equations for length and weight were Lt = 8.73[1?e?0.401(t + 0.947)]; Wt = 9.17[1?e?0.401(t + 0.947)]3.06. Oocyte numbers varied from 220 to 1159 and oocyte diameters ranged between 450 and 900 μm.  相似文献   

3.
Stuart  Ivor G.  McKillup  Stephen C. 《Hydrobiologia》2002,479(1-3):231-236
The relationship between the number of rings present in sagittal otoliths and the age of barramundi, Lates calcarifer (Bloch, 1790) [Centropomidae], was investigated by examining cross sectioned otoliths of 37 tagged fish of known age between 1 and 5 years from the Johnstone River, north Queensland. Concentric rings were clearly visible in all otolith sections and were validated as annual marks. The technique was then used to estimate the age and calculate von Bertalanffy growth parameters for 70 barramundi from the Fitzroy River, central Queensland. Growth appeared to be rapid but variable in the first year; the von Bertalanffy growth parameters for length versus age were L =690 mm, K=0.53, t 0= 0.003 years. October 1 was designated as the birth date. Whole otolith length, width and thickness were also approximated well by the von Bertalanffy equation. We suggest that examination of otoliths is a useful technique for ageing barramundi but note that further validation of the ageing method is still needed for fish older than six years.  相似文献   

4.
The ability to accurately estimate the age of fishes is critical for conducting stock assessments and developing fishery management policies. Scales were collected from albacore, Thunnus alalunga, caught in the Mediterranean Sea during the years 1989–1995 to estimate their age and growth. Ages, which ranged from 1+ to 6+ years, were estimated from the interpretation of the concentric rings on the scales of 473 individuals that ranged in fork length from 55.5 to 89 cm. Males reached a greater size and age than females. The relatively close agreement in the mean lengths at ages estimated by scales and other techniques constituted a preliminary verification of the method. The von Bertalanffy growth model was fitted to mean lengths at estimated ages, resulting in the following growth parameters for the combined sexes: L = 86 cm, K = 0.4, to = ?0.8 years. Parameter estimates were in agreement with what is known about life history of the species in the Mediterranean. Moreover, the growth rates were consistent with length increment observations from five tag returns, which lend support to our working hypothesis that the scale‐rings are annual structures. When the Mediterranean albacore growth parameters were compared with those of Atlantic Ocean albacore using scale age estimates, there were significant differences between the two populations, and Mediterranean albacore remain significantly smaller than Atlantic Ocean albacore.  相似文献   

5.
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 to = ?3.494.  相似文献   

6.
The age and growth of the Cyprinid fish Barilius moorii from Lake Kivu is studied by means of the growth rings occurring in the scales. Although the moment of ring formation and the duration of one growth season were not known, both overall length growth in a population as well as individual length growth could be calculated. Increase of weight was obtained from length growth on the basis of a length-weight relationship. By comparing the growth parameters of the von Bertallanfy equation and data from the literature, a hypothesis is formulated that ring formation should occur at the transition from a dry to a rainy season, and that two rings a year should be formed. Ring formation on the scales might be due to gonad maturation, but this could not be demonstrated.  相似文献   

7.
根据 5 5 1尾标本研究了生活在长江干流中圆筒吻的年龄与生长 ,并提出了资源合理利用建议。圆筒吻的鳞片可作为年龄鉴定的依据 ,年轮形成期主要在 2~ 5月。圆筒吻的体长与鳞长呈直线关系 ,与体重呈幂指数关系 ,生长适合VonBertalanffy生长方程。在 1~ 2龄生长最快 ,为保护圆筒吻资源 ,应限捕体长 2 0 0mm以下的个体  相似文献   

8.
V. S. Bhatt 《Hydrobiologia》1970,36(1):165-177
Summary Growth ofOphicephalus striatus was studied from zones on the scales as these were found to be suitable for age determination. Lenght estimates obtained from the scale reading were further substantiated by back-calculations. Thevon Bertalanffy equation was employed to find out theoretical values of length in respect of various year classes. The theoretical values agreed with the observed values very closely.Length-weight relationship showed that the weight of fish increases slightly faster than the cube of the length. Thevon Bertalanffy equation gave a good fit to weight-age data.  相似文献   

9.
根据551尾标本研究了生活在长江干流中圆筒吻(鱼句)的年龄与生长,并提出了资源合理利用建议.圆筒吻(鱼句)的鳞片可作为年龄鉴定的依据,年轮形成期主要在2~5月.圆筒吻(鱼句)的体长与鳞长呈直线关系,与体重呈幂指数关系,生长适合Von Bertalanffy生长方程.在1~2龄生长最快,为保护圆筒吻(鱼句)资源,应限捕体长200 mm以下的个体.  相似文献   

10.
11.
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 = 0.0034Lt3.22. This study presents the first estimation of the model parameters of the von Bertalanffy growth equation (L = 27.30 cm, = 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.  相似文献   

12.
Ages were estimated from otoliths, opercular bones, scales, and vertebrae of 514 specimens of Channa punctata from three Indian rivers – the Ganga, Gomti, and Yamuna – to evaluate the potential bias of age estimates between readers and between pairs of aging structures. Standard procedures were followed to prepare and study the age structures. Among all structures, otoliths showed highest (97.4%) values of agreement between readers' age estimates followed by the opercular bones (89.5%), scales (84.2%) and vertebrae (78.9%). Because of the highest percentage of agreement and lowest average percentage of error (0.05%) and coefficient of variation (0.76%) values between readers, otoliths were considered the most suitable aging structure for C. punctata. When otoliths ages were compared with those of the other structures viz., opercular bones, scales and vertebrae, percentage of agreement was found highest between estimates (90.8%) of otoliths and opercular bones.  相似文献   

13.
  • 1 Shell growth in the freshwater pearl mussel, Margaritifera margaritifera, was investigated. Three non‐linear growth models (i.e. power, logistic and von Bertalanffy) were fitted to Scottish length‐at‐age data sets and compared.
  • 2 Overall, the von Bertalanffy model outperformed the other two approaches, generating the smallest residuals in eight out of 11 samples (the logistic model provided slightly better fits to the other three). It was concluded that individual M. margaritifera appear to grow in an approximately asymptotic fashion and that the von Bertalanffy equation is an appropriate growth model to fit to freshwater pearl mussel length‐at‐age data.
  • 3 The ranges in von Bertalanffy parameter estimates observed (k = 0.023–0.075 year‐1, L = 77–158 mm, to = ‐3.93–4.33 years) are typical of those reported in northern European populations.
  • 4 Most of the populations investigated had relatively low k‐values and high maximum age (Amax) estimates. This feature, which suggests high long‐term productivity and less vulnerability to decline (i.e. larger, longer‐living mussels produce more offspring), may be a reason why these populations have survived until now. The population which appears to be the most vulnerable (i.e. which has the highest k and lowest Amax) is probably not recruiting adequately at present.
  • 5 An index of absolute growth (mean shell length‐at‐age) was also used for comparing different populations. Observed between‐ and within‐river differences in mussel growth patterns may be associated with a number of environmental factors, particularly water temperature and productivity.
  • 6 A significant positive relationship between river length and mean mussel length‐at‐age was observed. In general, mussels grow large in large, cold rivers and vice versa, although there are exceptions which suggest that additional factors may be involved.
  相似文献   

14.
This study investigated the age and growth of damselfish, Chromis notate, from Jeju Island in Korea. Samples were collected monthly by lift net from September 2013 to August 2014. Total lengths of the damselfish ranged from 6.4 to 15.3 cm. The relationship between total length and wet weight was WW = 0.0125TL3.1631 for females, and WW = 0.0091TL3.2769 for males. The slopes in the relationship between length and weight were not significantly different between sexes, but were significantly different in the intercepts. There were more female than male specimens (1.3:1). Age determination was conducted using the otoliths. Marginal increment (MI) declined in summer and winter, which suggests that two rings are formed each year. Ages of sampled individuals ranged from 1 to 5 years. Length‐at‐age data were fitted using the von Bertalanffy growth model. The estimated growth functions were Lt = 19.93 [1 ? exp?0.21 (t + 0.811)] total length and wet weight was females, and Lt = 16.47 [1 ? exp?0.32 (t + 0.499)] for males.  相似文献   

15.
The three-stage desk calculation of the von Bertalanffy equation to describe growth in height and weight with age in the elephant is compared with a new approach to calculating the three coefficients in the function by a computer. The two methods give different results with respect to the weight/age calculations. Theoretical von Bertalanffy equations calculated by both methods to describe growth in height and weight with age in the African elephant in Zambia are compared with previously published equations for the elephant in East Africa. Details are given of growth in height in two known-age African elephants, a female ‘Diksie’ and a male ‘Kartoum’. Theoretical growth in height curves for the female African and Asiatic elephant are compared. The coefficients K and / for growth in height are not transferable to the growth in weight equations. Inherent inaccuracies in the calculation of the coefficients in the von Bertalanffy equation are discussed, and it is concluded that in animals which have a long life-span such as the elephant, the equation serves as a purely empirical representation of weight-at-age data and that there is little biological significance in the parameters it contains. The computer-calculated curves give the best fit to the data. The regression of log age on log shoulder height from 2–20 years of age provides a more realistic approach to comparative growth studies. The increase in adrenal weight with age is linear. Tusk growth in relation to age and sex in Zambia is compared with East Africa. It is concluded that the tusks in Zambia are smaller and are more difficult to sex correctly than their East African counterparts, possibly a consequence of the Zambian elephant having a greater degree of tusk wear. Allometric growth is described with emphasis on the estimation of body weight from shoulder height. The most reliable estimates are obtained from a purely empirical representation of the data, a semilog plot of log body weight on shoulder height.  相似文献   

16.
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 Lt = 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.  相似文献   

17.
The aim of this work was to compare age determinations and precision using two deposition structures of trahira Hoplias malabaricus (Bloch, 1794): the scales, which are most frequently used, and otoliths (lapilli). The length‐age relationships were obtained with both structures and compared with results from previous studies. The 163 sets of trahira otoliths (lapilli) and scales were 17–46 cm standard length (SL) from Cayastá (Santa Fe) and Islas Lechiguanas (Entre Ríos), Paraná River, Argentina. Three independent readings of each structure were conducted. An age bias plot was performed to compare age estimations from scales and otoliths. To assess the precision of age determinations using both structures, the percent agreement among readers for both structures and the coefficient of variation were calculated (%CV). The age‐length relationships were plotted and fitted with the von Bertalanffy growth function for both structures and compared with previous works. Age readings recorded for scales were lower than those recorded for otoliths for ages above or equal to 3 years. Percent agreement among readers was higher than 80% for otoliths and less than 65% for scales. The%CV obtained for scales was 20% for young fish and 17% for adults. For otoliths the %CV was 7% for young fish and 3% for adults. The %CV obtained for scales was over the recommended limit (>7.6%). The von Bertalanffy parameters for scales were Linf = 45.80 mm; k = 0.29; t0 = ?1.34 and for otoliths were Linf = 40.76 mm; k = 0.39; t0 = ?1.05. Precision of age estimations assessed from the percent agreement and the coefficient of variation indicates that the scales of the trahira are inappropriate to estimate age in population studies for juvenile and adult specimens.  相似文献   

18.
An increased understanding of lake sturgeon (Acipenser fulvescens) population dynamics is a key requirement for successful management efforts. Little is known regarding the Grasse River population of lake sturgeon except that it is one of a few populations in New York State where spawning has been documented. Thus our purpose was to assess the current status of lake sturgeon in the Grasse River system, including age, growth, mortality, and abundance. Age was determined for 196 of 211 lake sturgeon by examination of sectioned pectoral fin rays. Ages ranged from 0 to 32 years and the annual mortality rate for fish between ages 7 and 14 was 16.8%. The weight (W, g) to total length (TL, mm) relationship was W = 1.281 × 10?6TL3.202. The von Bertalanffy growth equation was TL = 1913(1?e?0.0294(t+9.5691)). While the range of observed ages was similar to that of nearby St. Lawrence River populations, mean weight at age for an individual at 1000 mm TL was lower than that observed for lake sturgeon within Lake St. Francis of the St. Lawrence River. Predicted growth based on von Bertalanffy parameters was similar to that observed for the nearby Lake St. Francis. An open population estimator using the POPAN sub‐module in the Program MARK produced an abundance estimate of 793 lake sturgeon (95% CI = 337–1249).  相似文献   

19.
Check marks were found on the scales and opercular bones of Labeo senegalensis from Lake Kainji, Nigeria. The scale marks were often indistinct and difficult to interpret, but an attempt was made to determine age from the opercular bones.
At least two check marks per year were found on the opercular bones, one of these occurring during June-July, and the other during January. The relationship between opercular length and fish total length was plotted logarithmically and back-calculations of length made.
Problems of interpretation are discussed in relation to possible causes of ring formation.  相似文献   

20.
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, = 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.  相似文献   

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