scholarly journals Age and growth of bluemouth, Helicolenus dactylopterus, from the Portuguese continental slope

2009 ◽  
Vol 66 (3) ◽  
pp. 524-531 ◽  
Author(s):  
Vera Sequeira ◽  
Ana Neves ◽  
Ana Rita Vieira ◽  
Ivone Figueiredo ◽  
Leonel S. Gordo
Keyword(s):  
Continental Slope ◽  
Growth Increment ◽  
Age And Growth ◽  
Growth Equation ◽  
Daily Growth ◽  
Class 1 ◽  
Helicolenus Dactylopterus ◽  
The Mean ◽  
Von Bertalanffy Growth Equation ◽  
Age Estimates

Abstract Sequeira, V., Neves, A., Vieira, A. R., Figueiredo, I., and Gordo, L. S. 2009. Age and growth of bluemouth, Helicolenus dactylopterus, from the Portuguese continental slope. – ICES Journal of Marine Science, 66: 524–531. In all, 933 bluemouth (Helicolenus dactylopterus) were obtained from bottom-trawl research surveys along the Portuguese continental slope between October 2005 and February 2007 and from commercial landings. Age was determined by reading whole sagittal otoliths, and age estimates were validated by daily growth increment (DGI) analysis. Fish ranged from 5.2 to 44.9 cm, which corresponded to fish between 0 and 30 years old. The mean total length obtained from DGI analysis for age class 1 fish was 8.6 cm, corresponding to otoliths with a mean radius of 1.8 mm. As no statistical differences between sex were observed, the von Bertalanffy growth equation fitted was Lt = 45.50[1 − e−0.05(t+4.01)]. Comparisons with other studies using Hotelling's T2 test and the growth perform index (Ф) are drawn. The growth rates estimated in this study using whole otolith readings were the lowest of all the studies available, and the estimated L∞ is lower then those obtained for Azorean waters and higher than those published for the Mediterranean.

Effect of Individual Variability on the von Bertalanffy Growth Equation

1980 ◽  
Vol 37 (2) ◽  
pp. 241-247 ◽  
Author(s):  
K. J. Sainsbury
Keyword(s):  
Growth Models ◽  
Growth Increment ◽  
Mean Value ◽  
Individual Variability ◽  
Age And Growth ◽  
Growth Equation ◽  
Von Bertalanffy ◽  
Von Bertalanffy Model ◽  
The Mean ◽  
Von Bertalanffy Growth Equation

The growth in length of a group of animals is examined. Each animal is assumed to grow according to the von Bertalanffy model with fixed parameters, but these parameters are allowed to differ between individuals. Equations governing the mean and variance of length at given age and growth increment at given length are provided, and their implications discussed. Results indicate that the traditional growth equation is likely to result in an underestimate of the mean value of K when either length at age or growth increment data are analyzed. This problem does not appear serious when using length at age data. However, the problems of interpretation are more serious in the case of growth increment data where serious overestimates of the reconstructed mean length at age can result. A thorough analysis of growth cannot be made for a population exhibiting individual variability in L∞ and K from growth increment data alone. In particular a nonlinear relationship between growth increment and initial length does not necessarily imply that the von Bertalanffy model is inappropriate to the species in question. A topic urgently in need of examination is the form of the joint distribution of K and L∞ in animal populations.Key words: von Bertalanffy, growth models

Using traditional age and growth techniques in endangered species management: eastern freshwater cod, Maccullochella ikei

2008 ◽  
Vol 59 (8) ◽  
pp. 684 ◽  
Author(s):  
Gavin L. Butler ◽  
Stuart J. Rowland
Keyword(s):  
New South ◽  
Age And Growth ◽  
Growth Equation ◽  
Endangered Species Management ◽  
South Wales ◽  
Traditional Age ◽  
Von Bertalanffy Growth Equation ◽  
Relationship Of ◽  
Non Destructive ◽  
Age Estimates

Age and growth estimates can be difficult to obtain for endangered fishes owing to their relative low abundance and the ethics associated with sampling threatened populations. The eastern freshwater cod, Maccullochella ikei Rowland 1985, is an endangered freshwater fish endemic to the Clarence and Richmond Rivers of New South Wales, Australia. Bony parts were gathered from archival collections and hatcheries, as well as opportunistically from the wild, to determine age and growth. Examination of opercular bones and dorsal spine sections revealed no consistent annuli. Sectioned otoliths exhibited consistent bipartite rings throughout the structures and 106 otoliths were used to estimate the age of cod from 0+ to 15+ years. Edge increment analysis and known-age cod were used to validate the age estimates. The von Bertalanffy growth equation for M. ikei is Lt = 704.9 (1–exp (–0.20 (t + 0.14))). A length–weight relationship of W = 2.80 × 10–6 × L3.2467 was established from 372 cod collected using non-destructive techniques. Significant differences were found in the relative condition of cod in summer (Kn = 0.999) and winter (Kn = 1.026). The information presented in this paper will assist in the conservation of M. ikei and will provide a guide for future age and growth studies of threatened species.

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

scholarly journals Somatic growth and age of selected commercial fish species of the Cullera Coast, Iberian Peninsula, south-east Spain

2019 ◽  
Vol 66 (3) ◽  
Author(s):  
Angela Maria Jaramillo-Londono ◽  
Alejandra Vanina Volpedo ◽  
Jose Luis Diaz-Arevalo ◽  
Maria Eugenia Rodrigo-Santamalia ◽  
Vicent Bendito-Dura
Keyword(s):  
Fish Species ◽  
Somatic Growth ◽  
Mesh Size ◽  
Age And Growth ◽  
Biological Information ◽  
Growth Equation ◽  
Commercial Fish ◽  
Mullus Surmuletus ◽  
Von Bertalanffy Growth Equation ◽  
Uranoscopus Scaber

This work provides data on the somatic growth and age of selected commercial fish species of the Cullera Coast, Spain. The biological information available that permits responsible fishing management of these species is relatively scarce. This study was conducted in the Bay of Cullera, Spain (39º 12’to 38º 59’N, and 0º 09’to 0º 15’W); and selected benthic fish species were analysed that are frequently fished by trammel nets (mesh size 28-76 mm) at a maximum depth of 30 m. Maturity , age and growth of 63 torpedoes, Torpedo torpedo (L., 1758), 115 red scorpionfish, Scorpaena scrofa Linnaeus, 1758, 280 red mullets, Mullus surmuletus Linnaeus, 1758, 139 stargazers, Uranoscopus scaber Linnaeus, 1758, and 476 Portuguese soles, Dagetichthys lusitanicus de Brito Capello, 1868 were analysed. The data obtained in this study revealed that 50% of individuals of all the species reached sexual maturity at a TL (total length) of 20.0-36.5 cm and at an age of 2-6 years. The von Bertalanffy growth equation derived were: TL=37.0 (1 - e(-0.2(t + 0.33))); TL =31.5(1 - e(-0.38(t + 0.54))); TL =35.5(1 - e(-0.2(t + 2.08))); and TL =34.3(1 - e(-0.14(t + 2.16))) for S. scrofa, M. surmuletus; U. scaber and D. lusitanicus respectively.

scholarly journals Age, growth, and recruitment patterns of juvenile ladyfish (Elopssp) from the east coast of Florida (USA)

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1392
Author(s):  
Juan C. Levesque
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Age And Growth ◽  
Growth Equation ◽  
Length Frequency ◽  
Daily Growth ◽  
Exponential Regression ◽  
Absolute Growth ◽  
Specific Growth Rates ◽  
Size At Age

Ladyfish (Elopssp) are a common and economically valuable coastal nearshore species found along coastal beaches, bays, and estuaries of the southeastern United States, and subtropical and tropical regions worldwide. Previously, ladyfish were a substantial bycatch in Florida’s commercial fisheries, but changes in regulations significantly reduced commercial landings. Today, ladyfish are still taken in commercial fisheries in Florida, but many are also taken by recreational anglers. Life-history information and research interest in ladyfish is almost non-existent, especially information on age and growth. Thus, the overarching purpose of this study was to expand our understanding of ladyfish age and growth characteristics. The specific objectives were to describe, for the first time, age, growth, and recruitment patterns of juvenile ladyfish from the east coast of Florida (USA). In the Indian River Lagoon (IRL), annual monthly length-frequency distributions were confounded because a few small individuals recruited throughout the year; monthly length-frequency data generally demonstrated a cyclical pattern. The smallest were collected in September and the largest in May. Post-hoc analysis showed no significant difference in length between August and May, or among the other months. In Volusia County (VC), annual monthly length-frequency distribution demonstrated growth generally occurred from late-winter and spring to summer. The smallest ladyfish were collected in February and the largest in August. On average, the absolute growth rate in the IRL was 36.3 mm in 60 days or 0.605 mm day−1. Cohort-specific daily growth rates, elevations, and coincidentals were similar among sampling years. Cohort-specific growth rates ranged from 1.807 in 1993 to 1.811 mm day−1in 1994. Overall, growth was best (i.e., goodness of fit) described by exponential regression. On average, the absolute growth rate in VC was 28 mm in 150 days or 0.1866 mm day−1. Cohort-specific daily growth rates were significantly different among sampling years; however, the elevations and coincidentals were similar. Cohort-specific growth rates ranged from 1.741 in 1994 to 1.933 mm day−1in 1993. Mean ladyfish growth was best described by linear regression; however, natural growth was explained better by exponential regression. In the IRL, the corrected exponential growth equation yielded a size-at-age 1 of 156.0 mm SL, which corresponded to an estimated growth rate of 0.4356 mm day−1. In VC, the corrected exponential growth equation yielded a size-at-age 1 of 80 mm SL corresponding to an estimated growth rate of 0.2361 mm day−1.

Age and growth of the narrow-barred Spanish Mackerel (Scomberomorus commerson Lacepede, 1880) in North-eastern Queensland waters

1992 ◽  
Vol 43 (5) ◽  
pp. 1269 ◽  
Author(s):  
GR McPherson
Keyword(s):  
Growth Parameters ◽  
Age And Growth ◽  
Differential Growth ◽  
Daily Growth ◽  
Spanish Mackerel ◽  
Growth Increments ◽  
Scomberomorus Commerson ◽  
North Eastern ◽  
Marginal Increment ◽  
Age Estimates

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.

Age, growth and mortality of redfish Centroberyx affinis

2001 ◽  
Vol 52 (4) ◽  
pp. 637 ◽  
Author(s):  
A. K. Morison ◽  
K. R. Rowling
Keyword(s):  
Growth Rate ◽  
Significant Variation ◽  
Fork Length ◽  
Age And Growth ◽  
Average Error ◽  
Natural Mortality ◽  
Commercial Catch ◽  
Thin Sections ◽  
The Mean ◽  
Age Estimates

Age and growth of 5678 redfish, collected during 1991–98 from Australia’s South East Fishery, were estimated from thin sections of otoliths. A maximum age of 44 years was recorded for a 30 cm (fork length) female, but 80%of females in the commercial catch were <10 years, and 80%of males were <13 years. The largest was a 34 cm female estimated to be 36 years old. Repeated age estimates of a subsample revealed an average error of 3.79%. There was significant variation in the mean length-at-age among years, and there were significant effects for age*year, age*sex, age*region, region*year, and sex*region*year interactions. Assessments of the fishery have assumed a single stock, because tagging results from the 1980s indicate movement of redfish along the coast. This study found consistent differences in sex ratio and growth rate between regions, which indicate some structuring within the population. However, the differences in growth rates are not consistent among years and could not be explained by differences in depths fished, suggesting a more dynamic situation than spatially segregated stocks. Estimates of natural mortality ranged from 0.07 to 0.11 year–1 and differed between regions.

scholarly journals Age, growth, and recruitment patterns of juvenile ladyfish (Elops sp) from the east coast of Florida (USA)

2015 ◽  
Author(s):  
Juan C Levesque
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Age And Growth ◽  
Growth Equation ◽  
Length Frequency ◽  
Daily Growth ◽  
Exponential Regression ◽  
Absolute Growth ◽  
Specific Growth Rates ◽  
Size At Age

Ladyfish (Elops sp) are a common and economically valuable coastal nearshore species found along coastal beaches, bays, and estuaries of the southeastern United States, and subtropical and tropical regions worldwide. Previously, ladyfish were a substantial bycatch in Florida’s commercial fisheries, but changes in regulations significantly reduced commercial landings. Today, ladyfish are still taken in commercial fisheries in Florida, but many are also taken by recreational anglers. Life-history information and research interest in ladyfish is almost non-existent, especially information on age and growth. Thus, the overarching purpose of this study was to expand our understanding of ladyfish age and growth characteristics. The specific objectives were to describe, for the first time, age, growth, and recruitment patterns of juvenile ladyfish from the east coast of Florida (USA). In the Indian River Lagoon (IRL), annual monthly length-frequency distributions were confounded because a few small individuals recruited throughout the year; monthly length-frequency data generally demonstrated a cyclical pattern. The smallest were collected in September and the largest in May. Post-hoc analysis showed no significant difference in length between August and May, or among the other months. In Volusia County (VC), annual monthly length-frequency distribution demonstrated growth generally occurred from late-winter and spring to summer. The smallest ladyfish were collected in February and the largest in August. On average, the absolute growth rate in the IRL was 36.3 mm in 60 days or 0.605 mm day-1. Cohort-specific daily growth rates, elevations, and coincidentals were similar among sampling years. Cohort-specific growth rates ranged from 1.807 in 1993 to 1.811 mm day-1 in 1994. Overall, growth was best (i.e., goodness of fit) described by exponential regression. On average, the absolute growth rate in VC was 28 mm in 150 days or 0.1866 mm day-1. Cohort-specific daily growth rates were significantly different among sampling years; however, the elevations and coincidentals were similar. Cohort-specific growth rates ranged from 1.741 in 1994 to 1.933 mm day-1 in 1993. Mean ladyfish growth was best described by linear regression; however, natural growth was explained better by exponential regression. In the IRL, the corrected exponential growth equation yielded a size-at-age 1 of 156.0 mm SL, which corresponded to an estimated growth rate of 0.4356 mm day-1. In VC, the corrected exponential growth equation yielded a size-at-age 1 of 80 mm SL corresponding to an estimated growth rate of 0.2361 mm day-1.

scholarly journals Age, growth, and recruitment patterns of juvenile ladyfish (Elops sp) from the east coast of Florida (USA)

2015 ◽  
Author(s):  
Juan C Levesque
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Age And Growth ◽  
Growth Equation ◽  
Length Frequency ◽  
Daily Growth ◽  
Exponential Regression ◽  
Absolute Growth ◽  
Specific Growth Rates ◽  
Size At Age

Ladyfish (Elops sp) are a common and economically valuable coastal nearshore species found along coastal beaches, bays, and estuaries of the southeastern United States, and subtropical and tropical regions worldwide. Previously, ladyfish were a substantial bycatch in Florida’s commercial fisheries, but changes in regulations significantly reduced commercial landings. Today, ladyfish are still taken in commercial fisheries in Florida, but many are also taken by recreational anglers. Life-history information and research interest in ladyfish is almost non-existent, especially information on age and growth. Thus, the overarching purpose of this study was to expand our understanding of ladyfish age and growth characteristics. The specific objectives were to describe, for the first time, age, growth, and recruitment patterns of juvenile ladyfish from the east coast of Florida (USA). In the Indian River Lagoon (IRL), annual monthly length-frequency distributions were confounded because a few small individuals recruited throughout the year; monthly length-frequency data generally demonstrated a cyclical pattern. The smallest were collected in September and the largest in May. Post-hoc analysis showed no significant difference in length between August and May, or among the other months. In Volusia County (VC), annual monthly length-frequency distribution demonstrated growth generally occurred from late-winter and spring to summer. The smallest ladyfish were collected in February and the largest in August. On average, the absolute growth rate in the IRL was 36.3 mm in 60 days or 0.605 mm day-1. Cohort-specific daily growth rates, elevations, and coincidentals were similar among sampling years. Cohort-specific growth rates ranged from 1.807 in 1993 to 1.811 mm day-1 in 1994. Overall, growth was best (i.e., goodness of fit) described by exponential regression. On average, the absolute growth rate in VC was 28 mm in 150 days or 0.1866 mm day-1. Cohort-specific daily growth rates were significantly different among sampling years; however, the elevations and coincidentals were similar. Cohort-specific growth rates ranged from 1.741 in 1994 to 1.933 mm day-1 in 1993. Mean ladyfish growth was best described by linear regression; however, natural growth was explained better by exponential regression. In the IRL, the corrected exponential growth equation yielded a size-at-age 1 of 156.0 mm SL, which corresponded to an estimated growth rate of 0.4356 mm day-1. In VC, the corrected exponential growth equation yielded a size-at-age 1 of 80 mm SL corresponding to an estimated growth rate of 0.2361 mm day-1.

Biological and environmental rhythms reflected in molluscan shell growth

1968 ◽  
Vol 42 (S2) ◽  
pp. 64-80 ◽  
Author(s):  
Giorgio Pannella ◽  
Copeland Macclintock
Keyword(s):  
Shell Growth ◽  
Spring Tide ◽  
Growth Increment ◽  
Daily Growth ◽  
Mean Values ◽  
Daily Increments ◽  
Growth Increments ◽  
Tridacna Squamosa ◽  
The Mean ◽  
Daily Growth Increment

Tidal cycles are reflected in daily growth-increment sequences in shells of many Recent and fossil mollusks. Living specimens of the bivalve Mercenaria mercenaria were notched at the growing edge of the shell and planted intertidally in Barnstable Harbor, Massachusetts. Shells from two lots, killed at intervals of 368 and 723 days after planting, show the same number of small growth increments as there were days from notching to killing. Superimposed on daily growth record are effects of winter (thin daily increments) and tides (14-day cycles of thick and thin daily increments). Comparison of Barnstable tide record with the first year's growth shows that, for each 14-day cycle, thin daily increments form during neap tides and thicker daily increments form during spring tides. Although tidal patterns are present in subtidal Mercenaria shells, they are rarely as pronounced as in intertidal ones. Spawning patterns differ from winter patterns; they are expressed in the shell by an interruption of regular deposition followed by a series of thin daily increments. Continuous sequences of bidaily patterns, one thick daily increment followed by a relatively thin one, are common in M. mercenaria.The clearest 14-day cycles of deposition were seen in shells of the bivalve Tridacna squamosa. Each daily neap-tide increment is a simple layer consisting of a dark and light zone. Each daily spring-tide increment is a complex layer consisting of two light-dark alternations separated by a depositional break that is more pronounced than the breaks delimiting daily intervals. Preliminary results of growth-increment counts in fossils show a generally decreasing trend of the mean values of days per lunar month toward the Recent. The Pennsylvanian value is 30.07 ± 0.08, a figure that is in general agreement with those of Scrutton (1964), who counted 30.59 days per month on Devonian corals, and Barker (1966), who reported more than 30 days per month in Pennsylvanian bivalves.

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