title: Lévy processes and stochastic von Bertalanffy models of growth, with application to fish population analysis.
abstract: The study of animal growth is a longstanding crucial topic of theoretical biology. In this paper we introduce a new class of stochastic growth models that enjoy two crucial properties: the growth path of an individual is monotonically increasing and the mean length at time t follows the classic von Bertalanffy model. Besides the theoretical development, the models are also tested against a large set of length-at-age data collected on Atlantic herring (Clupea harengus): the mean lengths and variances of the cohorts were directly estimated by least squares. The results show that the use of subordinators can lead to models enjoying interesting properties, in particular able to catch some specific features often observed in fish growth data. The use of subordinators seems to allow for an increased fidelity in the description of fish growth, whilst still conforming to the general parameters of the traditional von Bertalanffy equation.
authors.affiliation: Laboratorio di Ecologia Sperimentale e Acquacoltura, Dipartimento di Biologia, Università di Roma Tor Vergata, Italy. Tommaso.Russo@Uniroma2.it
authors.forename: Tommaso
authors.initials: T
authors.lastname: Russo
authors.forename: Paolo
authors.initials: P
authors.lastname: Baldi
authors.forename: Antonio
authors.initials: A
authors.lastname: Parisi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Magnifico
authors.forename: Stefano
authors.initials: S
authors.lastname: Mariani
authors.forename: Stefano
authors.initials: S
authors.lastname: Cataudella
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D003627:Data Interpretation, Statistical; D005399:Fishes / Q000033:anatomy & histology / Q000254:growth & development*; D008954:Models, Biological; D013269:Stochastic Processes