scholarly journals Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast

2011 ◽  
Vol 71 (3) ◽  
pp. 755-761 ◽  
Author(s):  
JE. Kotas ◽  
V. Mastrochirico ◽  
M. Petrere Junior
Keyword(s):  
Growth Parameters ◽  
Growth Models ◽  
Calculated Data ◽  
Age And Growth ◽  
Brazilian Coast ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead ◽  
Marginal Increment ◽  
Best Fit

Age and growth studies for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) caught along the southern Brazilian coast, were based on ring measurements of vertebrae sections of 115 males, 116 females and 14 unknown sexed sharks between 48 and 344 cm total length (TL). The von Bertalanffy growth models were best fit using back-calculated data. The growth parameters obtained for males, were L∞ = 266 cm; K = 0.05/year; L0 = 47 cm. For females, L∞ = 300 cm; K = 0.05/year; L0 = 51 cm. An adult female reached 217 cm TL and was 31.5 years old. On the other hand, an adult male was 29.5 years old and measured 234 cm TL. Longevity estimate for males and females was 55 years. Therefore, S. lewini is a long-lived fish. Ageing precision, based on the IAPE index, was 5.6%. Marginal Increment analysis based on MIR index from hammerheads smaller than 105 cm, compared with the percentual of opaque and hyaline bands found per month ageing whole vertebrae, showed an annual ring formation, i.e., in winter.

Age and growth of the snowy grouper, Epinephelus niveatus, off the Brazilian coast

2011 ◽  
Vol 92 (3) ◽  
pp. 633-641 ◽  
Author(s):  
Paulo A.S. Costa ◽  
Adriana C. Braga ◽  
Juan P. Rubinich ◽  
Antônio Olinto Ávila-da-Silva ◽  
Cassiano M. Neto
Keyword(s):  
Life Span ◽  
Positive Relationship ◽  
Growth Parameters ◽  
Age And Growth ◽  
Brazilian Coast ◽  
Von Bertalanffy ◽  
South Eastern ◽  
Otolith Analysis ◽  
Eastern Brazil ◽  
Marginal Increment

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.

The use of caudal thorns for ageing Raja undulata from the Portuguese continental shelf, with comments on its reproductive cycle

2007 ◽  
Vol 58 (11) ◽  
pp. 983 ◽  
Author(s):  
Teresa Moura ◽  
Ivone Figueiredo ◽  
Inês Farias ◽  
Bárbara Serra-Pereira ◽  
Rui Coelho ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Growth Parameters ◽  
Growth Models ◽  
Geographical Area ◽  
Growth Function ◽  
Age And Growth ◽  
Reproductive Analysis ◽  
First Maturity ◽  
Size At Age ◽  
Best Fit

The present study focuses on age estimation, with reproductive information contributing to the better understanding of the growth and the biology of Raja undulata. In the age and growth study, two calcified structures were used: caudal thorns and central vertebra. Results of readings showed that there were no significant differences in age estimates between the two structures. Both von Bertalanffy and Gompertz growth models were fitted to size-at-age data by sex and geographical area. No significant differences were found between sexes for the two models but significant differences were found between geographical areas (P = 0.05). The Gompertz growth function was selected as the best model to describe R. undulata growth because it presented the best fit and the most reasonable biological estimates. Reproductive analysis indicates one annual breeding season for R. undulata. The differences found in the estimates of length at first maturity between geographical areas (TL50% = 838 mm in Peniche and 762 mm in Algarve for females and TL50% = 781 mm in Peniche and 736 mm in Algarve for males), together with the regional differences found between growth parameters estimates (P = 0.05), may reflect the existence of different local populations of R. undulata on the Portuguese continental shelf.

scholarly journals Age and growth estimates from three hard parts of the spotted catfish, Arius maculatus (Actinopterygii: Siluriformes: Ariidae), in Songkhla Lake, Thailand’s largest natural lake

2021 ◽  
Vol 51 (4) ◽  
pp. 371-378
Author(s):  
Penprapa Phaeviset ◽  
Pisit Phomikong ◽  
Piyathap Avakul ◽  
Sontaya Koolkalaya ◽  
Wachira Kwangkhang ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Growth Models ◽  
Stock Assessment ◽  
Age And Growth ◽  
Fish Stock ◽  
Von Bertalanffy ◽  
Pacific Population ◽  
Marginal Increment ◽  
Fish Stock Assessment ◽  
Songkhla Lake

The spotted catfish, Arius maculatus (Thunberg, 1792), is a euryhaline fish that is economically important in the Indo-West Pacific. Population dynamics studies and stock assessments of this species have focused on marine stocks, but not those from fresh water. In this study, the age and growth of A. maculatus were, therefore, investigated for the inland stock in Songkhla Lake, Thailand. A total of 213 individuals ranging between 35 and 238 mm TL were used. The length–weight relation indicated positive allometry of this population. Three hard parts (otolith, dorsal- and pectoral-fin spines) were used for aging. The marginal increment ratio confirmed that an annulus was deposited once a year in all three hard parts. All of the samples were aged between 0+ and 6+ years. Verification of age estimates from three readers showed that the otolith was the most suitable part for age estimation. Three growth models (von Bertalanffy, Gompertz, and logistic) were applied in the study. The von Bertalanffy model best described the growth of this fish in Songkhla Lake. The obtained asymptotic length was 290.87 mm TL and the relative growth rate parameter was 0.166 year–1. Our results will be applied as inputs for fish stock assessment models. The obtained growth parameters also can serve as a reference for A. maculatus stocks elsewhere.

scholarly journals Age and growth of the king mackerel (Scomberomorus Cavalla) off the northeastern coast of Brazil

2009 ◽  
Vol 57 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Marcelo Francisco de Nóbrega ◽  
Rosangela Paula Lessa
Keyword(s):  
Growth Parameters ◽  
Least Square Method ◽  
Least Square ◽  
Age And Growth ◽  
Northeastern Brazil ◽  
Von Bertalanffy ◽  
Growth Band ◽  
Marginal Increment ◽  
King Mackerel ◽  
Catch Composition

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.

Age, growth estimates for pink ling, Genypterus blacodes (Schneider), and gemfish, Rexea solandri (Cuvier), from Eastern Bass Strait, Australia

1989 ◽  
Vol 40 (2) ◽  
pp. 215 ◽  
Author(s):  
AF Withell ◽  
JWJ Wankowski
Keyword(s):  
Growth Parameters ◽  
Age And Growth ◽  
Frequency Method ◽  
Slow Growth Rate ◽  
Growth Functions ◽  
Significant Difference ◽  
Marginal Increment ◽  
Males And Females ◽  
Cent Error ◽  
Age Determinations

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.

Global phylogeography of the scalloped hammerhead shark ( Sphyrna lewini )

2006 ◽  
Vol 15 (8) ◽  
pp. 2239-2251 ◽  
Author(s):  
K. M. DUNCAN ◽  
A. P. MARTIN ◽  
B. W. BOWEN ◽  
H. G. DE COUET
Keyword(s):  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead
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