Capture, husbandry, and oxygen consumption rate of juvenile Pacific sleeper sharks ( Somniosus pacificus )

Few published studies have measured the oxygen consumption rates of elasmobranchs larger than 1.5 m, with only one measured at temperatures below 10 °C. This study provides initial measurements of the metabolic rate of three juvenile Pacific sleeper sharks, SP1904, SP1908, and SP2005 (199 cm, 162 cm, 144 cm), which were caught and temporarily housed at the Alaska SeaLife Center in Seward, Alaska. While at the Center, multiple respirometry trials were performed utilizing an intermittent-closed system respirometer to measure oxygen consumption. The average routine metabolic rates for each individual were calculated at 17.8 ± 1.3 mgO 2 kg −1 h −1 , 20.5 ± 1.6 mgO 2 kg −1 h −1 , and 4.0 ± NA mgO 2 kg −1 h −1 , respectively, while the resting metabolic rate of SP1908 was calculated at 14.3 ± 2.4 mgO 2 kg −1 h −1 . Oxygen consumption rates were measured between 6.0 and 8.8 °C. Both the active and resting metabolic rates for the Pacific sleeper shark were like those of the previously measured and closely related Greenland shark ( Somniosus microcephalus ) and the temperate zebra shark ( Stegostoma fasciatum ) when scaled to the temperature in this study. Therefore, Pacific sleeper shark metabolic rate is not unusually low compared to other shark species. These initial measurements of the metabolic rate of Pacific sleeper sharks enhance deep-sea and polar physiology knowledge by filling gaps in respirometry research for large, Arctic elasmobranchs.