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
Growth and size structure in a baltic Mytilus edulis population
TL;DR: This ability of M. edulis to “respire away its own biomass” and its apparent tolerance of weight loss has important implication for maintaining the strongly food-and space-limited Baltic M.Edulis population at the carrying capacity of the area.
Journal ArticleDOI
Reparameterizing, Fitting, and Testing a Simple Growth Model
TL;DR: In this paper, the von Bertalanffy growth model is used to statistically compare the properties of growth in two spatial regions by examination of the estimates of the growth parameter k and the asymptotic length parameter L∞.
Journal ArticleDOI
Large-scale intraspecific variation in life-history traits of European freshwater fish
Aurelie Blanck,Nicolas Lamouroux +1 more
TL;DR: Latitude, in contrast to habitat type, is an important factor influencing several traits of geographically widely dispersed populations of multiple European freshwater fish species, and traits such as growth rate, mortality rate and length of breeding season varied more between populations than between species.
Journal ArticleDOI
Variation in the life span and size of the freshwater pearl mussel
TL;DR: Within the distribution area of the freshwater pearl mussel, the maximum observed life span attained in a population varies from 30 to 132 years and the maximum shell length from 80 to 145 mm.
Elasmobranchs as living resources: advances in the biology, ecology, systematics, and the status of the fisheries. Proceedings
TL;DR: This report owes its genesis to the foresight and enthusiam of Dr. Kazuhiro Mizue, who contacted me in 1983 with his visionary ideas on cooperative programs.
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.