Age and growth determination of three sympatric wobbegong sharks: How reliable is growth band periodicity in Orectolobidae?

2013 ◽  
Vol 147 ◽  
pp. 413-425 ◽  
Author(s):  
Charlie Huveneers ◽  
Joanna Stead ◽  
Michael B. Bennett ◽  
Kate A. Lee ◽  
Robert G. Harcourt
Keyword(s):  
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.


KSTU News ◽  
2021 ◽  
pp. 11-25
Author(s):  
Beraki Weldegiorgish Teklekhaimanot ◽  
Sergey Vadimovich Shibaev ◽  
Sergey Yurievich Gulyugin

In this study, 292 blue sharks Prionace glauca (Linnaeus, 1758) (from 151 to 305 cm total length, TL) were collected off western Africa in the eastern central Atlantic Ocean between 1980 and 1982. Vertebral sections of females specimens ranged from 175 to 300 cm and males specimens ranged from 166 to 312 cm TL were processed and analyzed for age and growth parameters. Growth band pairs (translucent and opaque bands) were counted on the images photographed from the stained whole vertebrae using digital microscope called Digi Scope II. The band pairs after the birthmark were counted from 3 to 12 for males and from 4 to 13 for females. Growth parameters were derived using the Von Bertalanffy growth function (VBGF) based on FISAT and solver solution Microsoft excel and Ford Wall-Ford. VBGF was that which best fit the data. Parameters derived from the combination of observed and back-calculated lengths, K = 0.1, L_∞ = 386.4 cm and t_0 = −1.35 year for males and K = 0.12 year -1, L_∞= 355 cm and t_0 = –1.02 year for females were considered to best describe growth. The longevity was estimated to be at least 23.7 and 28.3 years for females and males respectively. The natural mortality rate was estimated to be 0.15 year - 1 and 0.18 year -1 for males and females respectively.


Author(s):  
J. D. Gage

Recoveries of tetracycline-labelled specimens of the sea urchin Echinus esculentus (Echinodermata: Echinoidea) from a wild population marked two years previously indicate very low skeletal growth rates in large adults. The post-tag growth in the test of a smaller specimen showed two clear growth zones in the middle layer of the plates, this conforming to the expectation of a single growth band each year. Merging of the spinochrome pigment bands present in the outer layer near the plate edge in older urchins will probably result in underestimation of age based on counts of these bands.The large literature on growth banding in the European sea urchin Echinus esculentus L. and other echinoids is reviewed by Pearse & Pearse (1975), Smith (1980) and Gage (1991). Moore (1935) utilised spinochrome pigment banding in the genital (apical) plates of E. esculentus from the Isle of Man (Irish Sea) and Firth of Clyde (western Scotland) in one of the first studies utilising growth bands to interpret the age structure and growth rates of sea urchins. A single band was assumed to be formed each year. Counts of spinochrome bands have been used to obtain nearly all subsequently published age data for this species (Sime, 1982; Nichols et al., 1985; Sime & Cranmer, 1985; Comely & Ansell, 1988).The present study was aimed at helping to resolve differing interpretations of age and growth rates in Echinus esculentus provided by these studies. This was undertaken by time marking the skeletal plates of a large sample of a wild population accessible by scuba diving on a submerged rock reef at 10–15 m depth off the islet of Eilean Mor near the Dunstaffnage Laboratory.


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.


2005 ◽  
Vol 62 (4) ◽  
pp. 655-670 ◽  
Author(s):  
Christoph Stransky ◽  
Sif Gudmundsdóttir ◽  
Thorsteinn Sigurdsson ◽  
Svend Lemvig ◽  
Kjell Nedreaas ◽  
...  

Abstract Age determination of Atlantic redfish (Sebastes spp.) has proven difficult and has led to inconsistent age and growth estimates in the past. Using otoliths of the two major commercial species, golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella), a series of exchange schemes was carried out to assess bias and precision of age readings between four readers and between two preparation methods. Considerable bias between readers and moderate precision were observed for the S. marinus readings, especially for ages >20 years, with coefficients of variation (CV) of 7.7–12.0% and average percent error (APE) of 5.4–8.5%. Agreement between readers increased from 17–28% to 45–61% when allowing deviations of ±1 year, and to 80–92% with ±3 years tolerance. The age of S. marinus determined from broken and burnt otoliths was estimated to be slightly lower than when the age of the same individuals was determined from thin-sectioned otoliths. The bias and precision estimates obtained from the S. mentella material were generally poorer than for S. marinus (CV 8.2–19.1%, APE 5.8–13.5%), but similar to reported values for other long-lived fish species. Better than 50% agreement was only achieved with ±3 years tolerance. Growth rates differed significantly between species, confirming slower growth for S. mentella. For S. marinus, only one reader comparison revealed significantly different growth functions, whereas almost all S. mentella reader pairs showed significant differences in growth curves. Section and break-and-burn readings of S. marinus did not differ significantly. Average ages of around 9–10 years were determined for juvenile S. mentella 24–30 cm long, which were likely to have migrated from East Greenland into the Irminger Sea, based on earlier observations. As some of the error in the age determinations presented could be attributed to interpretation differences between readers, further intercalibration of redfish ageing is urgently needed in order to provide consistent input data for stock assessment.


1973 ◽  
Vol 30 (5) ◽  
pp. 607-616 ◽  
Author(s):  
Richard J. Beamish

The use of the scale method to determine age of mature white suckers should be avoided. Sections of pectoral fin rays can provide accurate age determinations for most populations once the position of the first annulus has been identified. The age of immature white suckers can be estimated by both methods. It is suggested that, for identification of the first fin ray annulus and facility in the determination of the age of immature white suckers, both pectoral fins and scales should be sampled in all age and growth studies of this species.White suckers (Catostomus commersoni) from populations examined in this study attained ages of up to 17 years although little or no growth occurred in the latter years. Considerable variation in size at sexual maturity was found throughout the range for this species and, thus, the validity of a subspecies designation for a dwarf white sucker (C. c. utawana) based primarily on size differences should be reexamined.


2015 ◽  
Vol 96 (7) ◽  
pp. 1395-1402 ◽  
Author(s):  
Shoou-Jeng Joung ◽  
Chien-Chi Chen ◽  
Kwang-Ming Liu ◽  
Tzu-Chi Hsieh

The age and growth of Kwangtung skate, Dipturus kwangtungensis, in the waters off northern Taiwan were estimated from 422 specimens collected between July 2006 and July 2008 at the Tashi fishing market in north-eastern Taiwan. The sexes-combined relationship between total length (TL) and centrum diameter (D) was estimated as follows: TL = 14.11D0.888 (N = 411, r2 = 0.94, P < 0.001). Growth band pairs (comprised of translucent and opaque bands) in vertebrae were determined to form once annually, based on the centrum edge analysis. Up to 14 band pairs were found for both sexes. The von Bertalanffy growth function (VBGF), two-parameter VBGF, the Robertson function, and the Gompertz function were used to fit the observed length-at-age data. The Akaike information criterion corrected indicated that the Gompertz function best fit the observed length at age data. Sex-specific growth functions were not significantly different; the sexes-combined growth parameters were estimated as follows: asymptotic length (L∞) = 96.7 cm TL, growth coefficient (kG) = 0.144 year−1 and constant (t0) = 5.45 year (N = 364, P < 0.01).


IAWA Journal ◽  
1989 ◽  
Vol 10 (2) ◽  
pp. 133-145 ◽  
Author(s):  
Roland E. Vetter ◽  
Paulo C. Botosso

Specific data and comments are given on age and growth rate determination in trees of the Brazilian Amazon basin, based on longterm observation and research of diameter increment, radiocarbon dating, microscopic wood structure, and gamma- and X-ray densitometry; special attention is given to species of the unflooded Terra Firrne forest. Annual dry seasons in eastern Amazonia provoke periodical cambial activity which may be measured as variation in girth increment and is recorded in the wood anatomy as well as its density. Gamma radiation densitometry is discouraged because of poor results. X-ray densitometry and the radiocarbon method are promising but must be refined. Irregular specific climatic events should be considered to be possible natural marks.


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