Aquatic Ecophysiology: Physiological adaptations of high-latitude fish

In the first part of the course basic and general mechanisms of adaptation/acclimation and signal transduction is reviewed, with emphasis on endocrine regulatory mechanisms, including how hormonal signaling is regulated on different levels; production/secretion; plasma concentration and protein binding; receptor kinetics; second messenger regulation; clearance. The second part of the course is devoted adaptive mechanisms of high-latitude fish, in particular the anadromous life-strategy of the arctic charr and the physiological challenges and regulation of this life strategy, and the seasonally changes in food intake and growth characteristic for the anadromous charr. The regulation of the latter is revealed in relation to current knowledge on the endocrine regulation of long-term energy homeostasis in non-seasonal mammals (humans) and in relation to the photoperiodic regulation of a ¿sliding set-point¿ for energy homeostasis in seasonal mammals. The last part of the course is devoted the occurrence of persistent, organic pollutants such as polychlorinated biphenyls in high latitude animals and how these lipophilic pollutants behave in animals going through marked seasonal cycles in body fatness.

The aim of the course is to give the students a basic understanding of how regulatory signals are transduced and perceived in vertebrates, and how these signals regulate adaptations of fish living in a strongly seasonal environment in the north.

In addition the students will gain experience in reviewing and dissecting scientific publications.

Students who has completed the course should:

• Know how endocrine information is transduced between body compartments in vertebrates and how such information are perceived and output appropriate responses.
• Understand the challenges of living in an environment with strong seasonal changes in food availability and how long-term energy homeostasis is regulated in general (humans), in animals with regulated changes in seasonal food intake and growth (e.g. ground squirrel) and in fish.
• Understand the evolutionary background for the anadromous life strategy of salmonid fish, the physiological challenges of this life-strategy and the preparatory changes they undergo before seaward migration.
• Know the facts about the pollutant load in Arctic animals and the toxicokinetics of lipophilic pollutants (e.g. PCB) in animals undergoing strong seasonal changes in body fatness.
• Understand how research projects are conceived, accomplished and published.
• Evaluate established truths, and conclusions based on single studies.
• Understand that biological mechanisms and adaptations are multiple and complex.

Language of instruction and examination

Written exam (6 hours). The labreport must be approved. Alphabetical grades (A-F).