Temperature adaptation in the early ontogenesis of decapod crustaceans in the Humboldt Current

Abstract

The Humboldt Current System is a highly productive ecosystem supporting one of the world's largest fisheries. The oceanographic characteristics with year-round upwelling, low seasonality, and comparably low latitudinal changes allow wide distributional ranges of species. One of these species is the hairy crab Cancer setosus (Molina 1782) with a distributional range from 2 13'S to 46 00'S, which corresponds to a temperature range from ~10 to ~20 degree Celsius. The relatively temperature stable habitat is subjected to the El Nino Southern Oscillation, which might lead to drastic temperature changes of up to 10 degree Celsius. Temperature is one of the most important determining factors of species distribution. The early ontogeny of brachyurans was detected to be the bottleneck for survival, as the early life stages are especially sensitive to temperature changes. The pelagic phase presents the dispersal stage of the life cycle and influences biology, ecology, evolution and recruitment of a species. This study analyzed the influence of temperature changes on different levels of biological organisation at different simulated habitat temperatures ranging from 12 degree Celsius (LN temperature) to 24 degree Celsius (EN temperature). Results of this thesis show that C. setosus Zoeal instars react highly sensitive to temperature changes which is reflected in the whole organism function as well as in lower levels of organism complexity.