Habitat Selection by Two Species of Cleaner Fishes That May be Beneficial in Removing Sea Lice From Cultured Salmon

Abstract

Sea lice are detrimental ectoparasites that attach to Atlantic salmon causing physiological damage and costing farmers millions in inventory loss and treatments. Cleaner fishes have been introduced into sea cages to act as a biological control of sea lice which is likely a solution for Canadian salmon aquaculture industries. To improve cleaner fish foraging efficiency, this study seeks to determine the optimal habitat for cleaner fishes in Canadian aquaculture. I hypothesized that to be effective cleaner fishes, both the cunners and the lumpfish require habitats that provide them with shelter and places for rest because neither species live solely in the water column. My second hypothesis was that the cunners and the lumpfish require different habitats due to their different morphologies. Habitat comparisons were conducted with three habitats and a control in each individual fishes tank for a total of 8 cunners and 25 lumpfish. It was determined that only cunners required shelter, possibly due to the lumpfish’s ability to adhere to the glass tank walls for rest. Moreover, there was no significant difference in habitat preference between the two species. However, the lumpfish were less preferential between habitat and preferred three of the four habitats equally. It should be noted that the lumpfish and the cunners utilized the same habitats in separate ways to better fit their species-specific requirements; so future research on the co-existence of the two species could lead to increased foraging efficiency through two-species cleaner fish systems.