CONSERVATION AQUACULTURE FOR ENDANGERED KLAMATH BASIN SUCKERS Deltistes luxatus AND Chasmistes brevirostris

Lost River suckers (LRS, Deltistes luxatus )  and shortnose suckers (SNS, Chasmistes brevirostris) native to the upper Klamath Basin were determined  to be endangered in 1988.   Loss of  habitat, degradation of water quality including increased nutrient load contributing to increased algal growth, increased suspended sediment and increased  water temperature are considered some of the reasons for their decline along with overharvest and entrainment in water management structures.   The remaining populations continue to show poor survivorship and low recruitment .  In addition to habitat restoration c onservation aquaculture has become a very important element for maintaining biodiversity and  prevent  extinction by  supporting refugia populations.

Preliminary  work has begun to establish a conservation aquaculture protocol for the suckers .  Larval suckers are  collected as they move out of their stream spawning sites into the lakes.   These fish  are started on feed in aquaria then  stocked  outside in to ponds where they  are raised  for up to 2 years to a size (200 mm+) that will allow for increase survival in their native lakes.  One of the c ritical needs for this culture is a  knowledge of the nutrient requirements of the suckers from first feeding to grow-out size to  be able to produce fish that are fit and have high survivability.  This presentation will provide a  current  summary of the diet evaluation research for these fish.