A Test of the Relationship between Otolith Weight and Age for the Pilchard Sardinops neopilchardus

Fletcher, W. J.

doi:10.1139/f91-005

Cited by 50 publications

(60 citation statements)

References 3 publications

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“…Otolith growth will eventually uncouple with fish growth and a variety of factors, such as temperature and feeding conditions, influence the degree or timing of this uncoupling (Moksness et al 1995). Linear dimensions are likely to uncouple earlier than otolith weight be- cause as fish grow, otolith growth may not accumulate in the anterior-posterior axes (length), but rather continue to accrete to the medial axis (thickness, which is revealed in weight) (Wright et al 1990, Fletcher 1991, 1995, Wilson et al 2009). During the juvenile phase growth is fast and continuous, so both body and otolith morphometric characteristics are expected to have a strong association with fish age.…”

Section: Discussionmentioning

confidence: 99%

Predicting the age of sardine juveniles (Sardina pilchardus) from otolith and fish morphometric characteristics

2015

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Summary: An age prediction model based on individual morphometric characteristics (total length; weight) and otolith morphometric characteristics (diameter; weight) was investigated for juvenile sardine, Sardina pilchardus (Walbaum, 1792). Juveniles were collected from northern Portugal between May 2004 and January 2005. Daily growth rings were counted on the otoliths of 114 juveniles of 7-16 cm total length. The sample was divided into a training sample used to develop the age prediction model and a test sample used to evaluate the predictive ability of the model. The best model for predicting the logarithm of age was a linear regression with otolith diameter. The prediction of daily age was more accurate for younger (<200 days) juveniles. Overall, ages predicted from the model were unbiased in relation to ages determined from otolith microincrement counts. Moreover, predicted daily ages reproduced the overall shape of the observed age distribution and provided comparable growth estimates (0.041 cm day -1 ). The back-calculated birthdate period ranged from 29 September 2003 to 22 July 2004, with a peak in January 2004, which is consistent with the spawning season. The model presented here could be used as a method for increasing the volume of juvenile daily age data. Since growth and survival varies spatially and temporally, relationships between age and otolith/fish morphometry should not be extrapolated outside sampled periods, areas and fish size/age.

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Section: Discussionmentioning

confidence: 99%

Predicting the age of sardine juveniles (Sardina pilchardus) from otolith and fish morphometric characteristics

2015

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“…A positive strong correlation between the age-otolith length (r = 0.95), between the age-otolith width (r = 0.92), and between the age-otolith weight (r = 0.97) were also determined in all fish (Figure 4-12). The strong correlations between the age-otolith sizes have been determined by some researchers (Fletcher 1991;Fowler & Doherty 1992;Worthington et al 1995). According to Boehlert (1985), otolith weight and other measured variables could be used in age determination precisely.…”

Section: Resultsmentioning

confidence: 98%

“…They have no ventral fin (Geldiay & Balık 2007). (original) Relationships between otolith and age in fish have been determined by many researchers (Boehlert 1985;Pawson 1990;Fletcher 1991;Worthington et al 1995;Fowler & Doherty 1992;Araya et al 2001;Pilling et al 2003;Pino et al 2004;Samsun & Samsun 2006;Metin et al 2007;Metin & İlkyaz 2008).…”

Section: Introductionmentioning

confidence: 99%

Relationships between fish age and otolith size in spiny eel: Mastacembelus mastacembelus (Banks & Solander, 1794)

Eroğlu

Şen²

2015

Bitlis Eren University Journal of Science and Technology

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In this study, the relationships of age groups with length, width, and weight of sagittal otolith in a total 187 specimens belonging to the spiny eel, M. mastacembelus population inhabiting Karakaya Dam Lake were examined. Age groups of the population ranged between I and IX. The length, width, and weight of otoliths were found between 1.44 -3.82 mm, 0.80 -1.71 mm, and 0.30 -3.80 mg respectively. There was a stronger and positive linear relationship between the otolith size (length, width, and weight) and age groups.

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“…As a comparative method of estimating fish age from otoliths, otoliths from samples 3-6 were weighed to the nearest mg (n = 212), and from samples 3-8 otolith lengths were recorded to the nearest µm (n = 314) before sectioning (Fletcher 1991). From all samples a random subsample of otolith pairs were split, one otolith from each pair was sectioned in the normal way (see above), and the other was broken and burnt over an open flame in the same way both Mutch (1983) and Carter (1992) prepared their otoliths.…”

Section: Comparative Ageing Methodsmentioning

confidence: 99%

Age determination, validation, and growth of blue codParapercis colias, in Foveaux Strait, New Zealand

Carbines¹

2004

New Zealand Journal of Marine and Freshwater Research

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Blue cod (Parapercis colias) is an important inshore commercial and recreational fish species in the southern islands of New Zealand, and estimates of their growth rate, age at maturity, and longevity are required for fisheries management. This study provides validation and comparisons of ageing methodologies for blue cod in Foveaux Strait, Southland. Sectioned otoliths showed a consistent banding pattern, and counts of these had good consistency between readers. Scales, broken and burnt, and whole otoliths gave lower band counts than equivalent sectioned otoliths counts. Blue cod otoliths were small, and otolith weights and lengths showed no relationship with sectioned otolith band counts. Marginal increment analysis provided a partial validation of ages estimated from sectioned otoliths, and oxytetracycline marking completed the validation for blue cod over 300 mm total length. Fin spines also showed promise as an excellent and nonlethal ageing tissue. Blue cod growth in Foveaux Strait was then described and compared to previous studies, which are likely to have underestimated ages because of the use of broken and burnt and whole otoliths.

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A Test of the Relationship between Otolith Weight and Age for the Pilchard Sardinops neopilchardus

Cited by 50 publications

References 3 publications

Predicting the age of sardine juveniles (<em>Sardina pilchardus</em>) from otolith and fish morphometric characteristics

Predicting the age of sardine juveniles (<em>Sardina pilchardus</em>) from otolith and fish morphometric characteristics

Relationships between fish age and otolith size in spiny eel: Mastacembelus mastacembelus (Banks & Solander, 1794)

Age determination, validation, and growth of blue codParapercis colias, in Foveaux Strait, New Zealand

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