Early development and allometric growth patterns in Siberian sturgeon and their ecological significance

Early development of Siberian sturgeon Acipenser baeri was divided into two different phases. the prelarval stage between hatching (10.4-11.1 mm L-T) and first feeding (19.6-21.0 mm L-T), and the larval stage: between the ini tiation of external feeding and metamorphosis (28.6-32.4 mm L-T). Morphogen esis and differentiation were more intense during the prelarval than larval and early juvenile stages;the prelarval period was characterized by the re placement of embryonic adaptations and functions by definitive ones, such a s branchial respiration, exogenous Feeding, and active swimming. The positi ve allometry of the head for feeding, sensorial and respiratory functions ( inflexion point at 20.0 mm L-T), and the tail for reducing costs of transpo rt, routine swimming and escape reactions from predators (inflexion point a t 20-2 mm L-T) confirmed the hypothesis that growth patterns of early life stags closely match specific needs. (C) 1999 The Fisheries Society of the B ritish Isles.