Journal ArticleDOI
A new graphic method of describing the growth of animals.
TLDR
Growth curves, when conventionally plotted as length on age, are difficult to compare and classify; the usual mathematical methods of fitting them, such as the logistic and the Gompertz are rather laborious and incon venient for application to large numbers of individuals.Abstract:
Growth curves, when conventionally plotted as length on age, are difficult to compare and classify. Moreover, the usual mathematical methods of fitting them, such as, the logistic and the Gompertz are rather laborious and incon venient for application to large numbers of individuals. Fortunately, for many purposes, it is unnecessary to describe the whole growth curve; for the part below the inflection point is completed early and the part above the inflection point—the “? self-inhibiting― phase, covers the period of life when differences in growth are likely to be most striking. That phase of the growth curve can be appropriately represented by a straight line, the charac teristics of which can be treated statistically, by the following graphic method: Using arithmetic graph paper, with body length represented along both the x axis and along the y axis, plot length at ages 1, 2, 3, 4, 5@ n on the x axis against length at ages 2, 3, 4, 5, 6. n + 1, respectively, on the y axis. For several species on which I have found published length data, these points fall along a straight line. This line can be regarded as a sort of transformation of the usual growth curve, and in the following discussion I will call it that. The nine examples given in Figures 1—3are based on average lengths of large samples. When lengths of individual specimens are plotted by this method, a straight-line relationship is still obvious, though the points deviate more widely from the linethan when averages are used. These deviationsdoubtless result from several causes, among which random variations in environmental experience and errors of observation readily suggest themselves. For a few species the published growth data failed to produce a straight line. In these cases, the course of growth may differ from that in other animals; or the observed anomalies may reflect some artifactual effect in the data. Among those species for which this “? transformation― results in a straight line, the growth increments corresponding to equal time intervals, for example, be tween years of age (12 —? 11,13 —? 12,14 —? i@, @l,—? i@), have the following inter relations; where 1,, refers to the length at any given age, i.e., at the end of any given time interval :2read more
Citations
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Journal ArticleDOI
Age, growth, and condition of European eel (Anguilla anguilla) from six lakes in the River Havel system (Germany)
TL;DR: The condition and the growth rate, estimated by otolith increments, varied between eels within single lakes and between lakes, and the only difference observed was a trend towards slower growth.
Journal ArticleDOI
Re-appraisal of age composition, growth and survivorship of the deep-sea brittle star Ophiura ljungmani from size structure in a sample time series from the Rockall Trough
J. D. Gage,P. A. Tyler +1 more
TL;DR: The present study of the revised data shows that settlement of Ophiura ljungmani (Lyman) occurs in summer when disk-size frequencies are dominated by the newly metamorphosed postlarvae.
Journal ArticleDOI
Growth, diet and condition of goldsinny on the west coast of Scotland
TL;DR: There were differences in Ks, GSI, HSI and dietary trends associated with variation in season, sex and location and the implications of this variation are discussed in relation to the management of a sustainable goldsinny fishery.
Journal Article
Age and growth in two marine portunid crabs, Portunus (Portunus) sanguinolentus (Herbst) and Portunus (Portunus) pelagicus (Linnaeus) along the southwest coast of India
K K Sukumaran,B Neelakantan +1 more
TL;DR: The size frequency analysis indicated that the growth rate was high and more or less uniform in juveniles, while the adults showed relatively low rate of growth and marked variation in males and females.
Journal Article
Population dynamics of Nemipterus japonicus (block)In the trawling grounds off Madras
E Vivekanandan,D B James +1 more
TL;DR: Both the annual stock and the standing crop are higher than the estimated annual catch, indicating that the present fishing effort can safely be increased without the stock being affected.
References
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Book
On Growth and Form
TL;DR: This book is an application of some of the concepts of physical science and sundry mathematical methods to the study of organic form and is like one of Darwin's books, well-considered, patiently wrought-out, learned, and cautious.
Journal ArticleDOI
Latitude and Relative Growth in the Razor Clam, Siliqua Patula
TL;DR: Current mathematical expressions for the course of growth are discussed and a formula used which emphasises Minot's conception of a growth-rate constantly declining with age is found to graduate the extensive data in clam growth with significant accuracy.