Pond Loach Survival in Low Dissolved Oxygen

Authors: William Tobias, Charles Cotton

SUNY Campus: SUNY Cobleskill

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 57

Timeslot: Session B 10:15-11:15 AM

Abstract: Pond loach (Misgurnus anguillicaudatus) are facultative air breathers known to survive periods of low dissolved oxygen by gulping air at the surface. They highly resilient fish are able to survive in extreme conditions such as hypoxia, as well as a wide range of pH and water temperatures, making them a hardy invasive species when found outside their native range in Eastern Asia. In this study, we tested the hypothesis that pond loach could not survive in hypoxic conditions if they were prevented from reaching the water’s surface. Three replicated treatments were set up in glass aquaria, including surface-obstructed, unaerated, and control with supplemental aeration. Mortality, dissolved oxygen, and pH were measured every 4 hours for 2 weeks. Within 5 days, no fish from the surface-obstructed group survived, while all fish from the other two groups survived until the end of the experiment. Therefore, we concluded that pond loach survival during periods of hypoxia was prohibited if loach are trapped underwater and prevented from air-breathing. These results present a possible control method for invasive pond loach versus more common and expensive methods such as rotenone, which is largely ineffective for species that can tolerate low dissolved oxygen.