Dr. Sjannie Lefevre from the University of Oslo, Norway, is visiting UAA to work with Dr. Jonathan Stecyk on the physiology of the Alaska blackfish, Dallia pectoralis. The Alaska blackfish is the only air-breathing fish known to inhabit arctic regions, and it is puzzling why the fish has evolved to air-breathe when the behaviour is restricted by the ice covering lakes and rivers half of the year, though air-breathing would be beneficial during the higher temperatures and low oxygen levels during the summer. The purpose of the project is therefore is to investigate how the air-breathing fish copes with low oxygen levels at different temperatures. Dr. Lefevre uses a special form of respirometry, which simultaneously measures the oxygen consumption of the fish from air and water, thus revealing the importance of air-breathing in different situations, and how oxygen consumption is impaired when access to air is restricted.

Fig. 1. Drs. Lefevre and Stecyk catching Alaska blackfish at Little Campbell Lake.

Fig. 1. Drs. Lefevre and Stecyk catching Alaska blackfish at Little Campbell Lake.

Fig. 2. The Alaska blackfish.

Fig. 2. The Alaska blackfish.

Fig. 3. A schematic of the dual-phase respirometer utilized to measure the aerial and aquatic oxygen consumption of the fish.

Fig. 3. A schematic of the dual-phase respirometer utilized to measure the aerial and aquatic oxygen consumption of the fish.