Ludwig von Bertalanffy was a key figure in the advancement of theoretical biology. His early considerations already led him to recognize the necessity of considering the organism as a system, as an organization of parts and processes. He termed the resulting research program organismic biology, which he extended to all basic questions of biology and almost all areas of biology, hence also to th...

The growth of Biomphalaria glabrata, B. schrammi, Drepanotrema lucidum and D. kermatoides was studied in three habitatis on Guadeloupe. Theortical growth curves were calculated for each species by applying the Walford method and the von Bertalanffy equation. On Guadeloupe, the growth of B. glabrata was faster in the ponds of Grand Terre than in the small high altitude streams of Basse Terre. Th...

This article offers a concise survey and glimpse of the vast literature presently available in the field of systems thinking and cybernetics. The first part discusses the areas of systems philosophy, systems analysis (mathematical systems theory), empirical systems research, and systems engineering, while the second part offers some details about the contributions of the following selected scho...

We consider three individual-based models describing growth in stochastic environments. Stochastic differential equations (SDEs) with identical von Bertalanffy deterministic parts are formulated, with a stochastic term which decreases, remains constant, or increases with organism size, respectively. Probability density functions for hitting times are evaluated in the context of fish growth and ...

Graphical representations of the response surface of the ELEFAN I software for estimation of the von Bertalanffy growth parameters L_ and K are given, based on length-frequency data on Engraulis ringens, Upeneus moluccensis and Sarda chiliensis. These 3D plots of a goodness-of-fit index us. L~ and K, obtained using a CRAY XMP/48 supercomputer, illustrate several problems associated with paramet...

The objective of this work was to evaluate the Nelore beef cattle, growth curve parameters using the Von Bertalanffy function in a nested Bayesian procedure that allowed estimation of the joint posterior distribution of growth curve parameters, their (co)variance components, and the environmental and additive genetic components affecting them. A hierarchical model was applied; each individual h...

in this study, 160 fishes were randomly collected from commercial catch by a cone net in babolsar port from january to october 2010. the biological features of specimens were measured. 2 + years old fishes made the dominant age group with 33.75% and 1 + and 5 + years old had the least frequency (8.75%). relationship between length and weight indicated negative allometric growth pattern (b=2.581...

The tambaqui, Colossoma macropomum, is one of the most commercially valuable Amazonian fish species, and in the floodplains of the region, they are caught in both rivers and lakes. Most growth studies on this species to date have adjusted only one growth model, the von Bertalanffy, without considering its possible uncertainties. In this study, four different models (von Bertalanffy, Logistic, G...