Comparative allometric growth of rare minnow (Gobiocypris rarus) in two culture environments

Abstract

Allometry, a growth pattern in which different parts of an organism grow at defined rates, is a common feature of fish and can be influenced by environmental factors. The rare minnow Gobiocypris rarus Ye et Fu, 1983 undergoes allometric growth, and this study investigated its allometry patterns and assessed whether the culture environment affects them by comparing growth patterns in conventional (CV) and specific pathogen-free (SPF) stocks using 14 morphological characters. A U-shaped pattern of allometric growth was found in both groups, characterized by higher growth rates of the head and caudal regions than the trunk region. Although the overall allometric growth pattern was similar between these two inbred groups of rare minnows, allometric coefficients for morphometric characters before inflection were higher for SPF fish than CV fish. Growth rates of total length and body mass were also higher for SPF than CV individuals. These results indicate that the environment does play a vital role in rare minnow growth and development, and that a clean culture environment and a U-shaped pattern of allometric growth are highly beneficial for its early growth.