scholarly journals Age and growth of the undulate ray, Raja undulata, in the Algarve (southern Portugal)

Author(s):  
Rui Coelho ◽  
Karim Erzini

Aspects of the population dynamics of the undulate ray, Raja undulata (Chondrichthyes: Rajidae), one of the more abundant elasmobranch fish captured along the Portuguese south coast (Algarve), were studied for the first time. Some traditional elasmobranch vertebral enhancing techniques were compared and the most precise for this species determined to be the cedar wood oil immersion and the alizarin red S stain. The sample consisted of 14 age-classes, with age-classes 3 to 8 being the most represented. Evidence of an annual deposition pattern of a pair of bands (one opaque and one translucent) was found by marginal increment analyses. Von Bertalanffy growth parameters were estimated and no differences found between males and females (all data: Linf=110·22 cm, K=0·11 y−1 and t0=−1·58 y).

Author(s):  
Hasna Kadri ◽  
Sondes Marouani ◽  
Mahamed Nejmeddine Bradai ◽  
Abderrahmen Bouaïn ◽  
Eric Morize

The age, growth, longevity, mortality and reproductive parameters were estimated for Dipturus oxyrinchus from the Gulf of Gabès (Southern Tunisia, central Mediterranean Sea), collected monthly during 2007 from commercial fisheries. The present study provides the first data on age and growth of this species in Tunisian waters, as well as additional data on its reproduction. A total of 240 females (16.5–105 cm total length (TL)) and 280 males (15.5–95 cm TL) were examined to study the reproductive cycle. A subsample of 285 specimens (175 females and 110 males, ranging from 15.5 to 105 cm TL) were analysed to study the age and growth. The oldest female in this study was 25 yr and 105 cm TL, whereas the oldest male was 22 yr and 95 cm. The annual deposition of growth bands was verified by marginal increment and edge analysis. The von Bertalanffy growth parameters were L∞ = 123.9 ± 2.56 cm, K = 0.08 ± 0.004 yr−1 and t0 =  −1.26 ± 0.04 10−1 yr for females and L∞ = 102.1 ± 3.23 cm, K = 0.12 ± 0.007 10−3 yr−1 and t0 = −1.18 ± 0.03 10−1 yr for males. Growth was not significantly different between sexes. The maturity size was 72.05 cm for males and 82.1 cm for females. The maturity age was estimated to be 11.95 and 13.96 years, respectively, for males and females. Size and age at maturity were not significantly different between sexes. The estimated longevity was 26.18 and 38.84 yr for males and females, respectively. Based on life history parameters, natural mortality was estimated at 0.53 yr−1 for females and 0.41 yr−1 for males.


1989 ◽  
Vol 40 (2) ◽  
pp. 215 ◽  
Author(s):  
AF Withell ◽  
JWJ Wankowski

Age and growth were estimated from counts of otolith annuli for pink ling (Genypterus blacodes) and gemfish (Rexea solandri). Sections of otoliths were preferable for age determinations of pink ling, whereas whole otoliths were preferable for gemfish. Validation of the assigned age classes was not achieved. Petersen's length-frequency method was unsuccessful and marginal increment methods were unsuitable for the species studied. Growth of males and females did not differ significantly for either pink ling or gemfish. Both species had a relatively slow growth rate, had a moderately long life-span and could reach body lengths in excess of 1 m. Maximum ages of pink ling and gemfish were, respectively, 21 and 13 years. Mean length-at-age and the von Bertalanffy growth functions were estimated. For pink ling (all individuals combined), K = 0.095 and L∞ = 135.5 cm. For gemfish the best estimates were K = 0.153 and L∞ = 112.3 cm. Precision of age determinations made independently by two readers for pink ling and gemfish, respectively, was 65% and 95% within �1 annulus; average per cent error, respectively, was 4.7% and 3.1%. Paired t-tests on ages assigned to each species by the two readers indicated no significant difference between ages assigned to gemfish, but there was a significant, albeit unbiased, difference for ages assigned to pink ling. However, for pink ling, estimates of the growth parameters derived separately from age determinations by the two readers were virtually identical.


2011 ◽  
Vol 101 (4) ◽  
pp. 304-309 ◽  
Author(s):  
Talitha M. Francisco ◽  
Angela Maria Ambrósio ◽  
Thiago José Balbi ◽  
Marina S. Zuliani ◽  
Edson K. Okada ◽  
...  

Age and growth parameters of cachara Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) (Siluriformes, Pimelodidae) (males and females) were estimated through the analysis of growth rings in spines of pectoral fins. Fish were collected from January to December 2007, in the area directly influenced by the Aproveitamento Múltiplo de Manso (APM Manso) and in the Cuiabá River (upper parts of the Pantanal). The maximum number of growth rings was seven for males, and eight, for females. The analysis of temporal variations in mean marginal increment showed that rings found in the spines were formed annually, in December. Growth rings were associated to spawning (in the study region from November to March) of the species. The growth curve in length was obtained by the von Bertalanffy model adjusted by the Ford-Walford transformation. The equations are: Ls = 72.7*[1-e-0.44(t+1.5974)] for males, and Ls = 84.5*[1-e-0.33(t+2.0943)] for females. The equations that describe the growth curve in weight are: Wt = 4991.61*[1-e-0.44 (t+1.5974] 2.70 for males and Wt = 7503.17*[1-e-0.33 (t+2.0943] 2.99 for females.


1989 ◽  
Vol 40 (6) ◽  
pp. 679 ◽  
Author(s):  
RWJ Pidgeon

The freshwater herring, Potamalosa richmondia Macleay, is a catadromous fish that inhabits coastal rivers of New South Wales. Estimates of the age and growth of this species in the Bellinger River were made from scales. Comparison of scale ages with those from whole otoliths and burnt otolith sections from a sample of 30 fish aged at 2 to 8 years resulted in a 73 and 79% exact agreement and a 97 and 100% agreement within one year, respectively. Marginal-increment analysis of the scales indicated that the annulus was formed during the winter, which is also the spawning season. The ageing method was validated for age classes of 2 to 8 years by these procedures. The age at the first annulus and at ages 9 to 11 years could not be validated. The oldest fish examined was estimated to be 11 years old. The growth rate was very slow in comparison with that of other clupeids. Parameters of the von Bertalanffy growth equation, based on lengths and ages at capture, were L∞ = 252.7 mm, K = 0.126, and t0 = -2.77 years. There was no difference between the sexes in their growth in length. However, the length-weight relationships of males and females were different, with females longer than 180 mm weighing more than males of the same length. The predicted weights at the asymptotic length were 213.2 g for males and 257.6 g for females.


2009 ◽  
Vol 60 (5) ◽  
pp. 394 ◽  
Author(s):  
Francisco Cerna ◽  
Roberto Licandeo

The shortfin mako, Isurus oxyrinchus, is a large pelagic shark with a widespread global distribution. However, very little is known about most aspects of this species for the south-eastern Pacific. In the present paper, the age and growth parameters of the shortfin mako, caught by Chilean swordfish longline fisheries from 2004 to 2005, are reported. Ages were estimated by counting band-pairs from sections of vertebral centra from 547 individuals, ranging from 76 to 330 cm in total length (TL). Trends in the proportion of opaque edges for all ages combined and grouped into ages 0–6 and 7–26 years indicated that they are formed during summer and showed that annually, one band-pair is formed in the vertebrae of shortfin makos. Modal-progression analysis was used to verify the first three age classes (ages 0–2 years). For both sexes, the oldest estimated age was 25+ years. Von Bertalanffy growth parameters were estimated at L∞ = 325.29 cm TL, K = 0.076 year–1 and t0 = –3.18 years for females and L∞ = 296.60 cm TL, K = 0.087 year–1 and t0 = –3.58 years for males. The results indicated that this species is highly vulnerable to exploitation and, thus, urgent conservation measures are required.


2009 ◽  
Vol 57 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Marcelo Francisco de Nóbrega ◽  
Rosangela Paula Lessa

Age and growth of the king mackerel (Scomberomorus cavalla) were estimated for northeastern Brazil. A total of 405 sagittal otoliths from 140 males (24.4-112 cm), 73 females (28-114.8 cm) and 193 specimens of unknown sex (11.5-121 cm) were examined. Marginal increment analysis indicated an annual pattern for growth band deposition. The age classes ranged from 1 to 15 years. Length ranged from 11.5 to 121 cm. The Schnute model indicated that the von Bertalanffy growth model demonstrated the best adjustment, with p=1/b, and was therefore used for estimating growth. Back-calculated curves had smaller variances, giving the following estimated growth parameters for males: L∞= 116.8 cm, K = 0.190, t0 = 0.377; and females: L∞= 132.7 cm, K = 0.159 and t0 = 0.387. In order to compare the curves for males and females, the overlapping of 95% confidence intervals was performed for the parameters generated from the von Bertalanffy non-linear least square method. Specimens between 3 and 8 years of age represented 82.2% (n=5,783) of the catch composition, characterizing the species as a catchable stock in the region.


1992 ◽  
Vol 43 (5) ◽  
pp. 1269 ◽  
Author(s):  
GR McPherson

Whole otoliths were used to age Scomberomorus commerson in tropical Australian waters. Age estimates were validated by marginal-increment analysis of the first three otolith annuli. Confirmation of age estimates was provided by otolith daily growth increments and tag returns of known age. Differential growth in length, weight and longevity was evident between the sexes. The oldest male was 10 years old (127 cm FL, 19.0 kg). The oldest female was 14 years old (155 cm FL, 35 kg). The von Bertalanffy growth parameters L∞ and K were 127.5 cm and 0.25 for males and 155.0 cm and 0.17 for females.


2014 ◽  
Vol 65 (12) ◽  
pp. 1145 ◽  
Author(s):  
Hua Hsun Hsu ◽  
Shoou Jeng Joung ◽  
Robert E. Hueter ◽  
Kwang Ming Liu

This study estimated age and growth of the largest extant fish, the whale shark (Rhincodon typus) by counting vertebral band pairs from 92 specimens comprising 43 males (2.68–9.88 m total length [TL]), 30 females (1.60–7.02 m TL), and 19 unsexed individuals (2.83–6.67 m TL) taken by Taiwanese commercial fisheries during 2001–06. Growth band pairs up to 25 and 42 were counted for a 6.38-m TL female and a 9.88-m TL male, respectively. Using marginal increment ratio and centrum edge analysis, band pairs were postulated to be formed twice a year. The two-parameter von Bertalanffy growth function provided the best fit without significant differences between sexes. Growth parameters were calculated for both sexes as L∞ = 16.80 m TL, k = 0.037 year–1; annual band pair formation would modify these parameters to L∞ = 15.34 m TL, k = 0.021 year–1. Using data reported in another study for 50% size at maturity for males (8.1 m TL), and the largest immature and smallest mature females (8.7 and 9.6 m TL, respectively) in the Indo-Pacific, these TLs converted to ages at maturity of 17 years for males and 19–22 years for females. The longevity was calculated to be 80.4 years.


Author(s):  
Paulo A.S. Costa ◽  
Adriana C. Braga ◽  
Juan P. Rubinich ◽  
Antônio Olinto Ávila-da-Silva ◽  
Cassiano M. Neto

The age and growth of the snowy grouper, Epinephelus niveatus, from central and south-eastern Brazil were studied by otolith analysis from a sample of 341 specimens, ranging from 325 to 1216 mm in total length (TL) caught with bottom longlines between 1996 and 1998. Otolith length grew proportionally with the increasing TL of the fish. Marginal increment analysis indicated that a single opaque band forms each year during autumn–winter. The maximum estimated age was 54 years, which significantly extends the previously estimated life-span of 21–29 years for this species. The von Bertalanffy growth parameters for both sexes were estimated as L∞ = 1098.4 mm TL, K = 0.062 year −1 and t0 = –2.68. The study revealed differences in mean length-at-age and size at recruitment, as well as in growth parameters between the central and the south-eastern Brazilian coast, which can be attributed mainly to different fishing pressures. The snowy grouper was found at depths of 82–492 m, and showed a positive relationship between age and depth, suggesting differential movements of older fish to deeper waters.


2011 ◽  
Vol 9 (2) ◽  
pp. 393-401 ◽  
Author(s):  
Marília Previero ◽  
Carolina V. Minte-Vera ◽  
Matheus Oliveira Freitas ◽  
Rodrigo Leão de Moura ◽  
Claudenice Dei Tos

We determined the age and growth of the dog snapper (Lutjanus jocu), caught in the region of Abrolhos Bank, Bahia State, by the fishermen from coastal communities of Prado, Alcobaça, Caravelas, and Nova Viçosa. We examined 205 sectioned otoliths of fish caught by harpoon, longline, hand line, and gill nets (14.5 to 79.5 cm fork length). The formation of each ring was considered annual. The sectioned otoliths showed between 0 and 29 rings. Nearly half of the analyzed specimens had between 0 and 7 rings (88 of 205). Fish caught with nets in the estuarine region were the juvenile, while fish caught with lines and harpoons were the oldest. Two von Bertalanffy growth models were fitted to length-at-age data: one assuming constant variance of length-at-age (SVB) and another assuming constant coefficient of variation, i.e. variance increasing as a function of average size (CVVB). The SVB estimates were Loo = 87.82 cm, K = 0.10, and t0 = -1.486 and the CVVB estimates were Loo = 117.60 cm, K = 0.06, and t0 = -2.470. The largest Loo values estimated by the CVVB model are supported by reports from the literature of larger animals occurring in the deeper outer shelf of Abrolhos Bank. Growth parameters were also estimated for males and females separately (SVB model) (Loo = 92.80 cm, K = 0.099, and t0 = -1.680 for males, and Loo = 82.10 cm, K = 0.105, and t0 = -1.570 for females).


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