The widespread used antiparasitic Ivermectin disrupts swimming behavior on the freshwater fish Prochilodus lineatus (Teleostei, Characiformes)

LOZANO, I.; DE LA TORRE F.; BABAY, P.; PIAZZA, Y.; LO NOSTRO, F.

Texas

Congreso; SETAC YES; 2020

Society of Environmental Toxicology and Chemistry

Ivermectin (IVM) is an antiparasitic drug widely used to treat parasites of humans, livestock, and fish. IVM is excreted unchanged (90 %) in dung of treated animals. Residues may affect nontarget organisms living in water bodies close to dung depositions areas. Laboratory toxicity tests provide inexpensive and accurate methods for assessing a chemical?s potential to affect fish behavior; however endpoints related with locomotor activity have not been previously analyzed. We analyze the swimming behavior on the Argentinian native fish Prochilodus lineatus exposed to sublethal concentrations of IVM. Water renewal and IVM stability time were evaluated by HPLC-UV. Four treatments were tested: control (C), vehicle (Cv), 0.5 µg / L (IVM 1) and 1.5 µg / L (IVM 2), both environmental relevant concentrations. At the end of the exposure, using Ethovision XT14 and Tracker 5.04 software, each aquarium was video-recorded during 10 minutes assessing: routine swimming speed, total distance traveled, % of movement, water column use and burst swimming. In a tablet pc-mounted in a side of the aquarium, a black oval animation simulating a frontal silhouette of an attacking predator was projected to trigger the escape response. The escape motion for the burst swimming was recorded at 400 fps in order to determine the acceleration and speed during evasion. Results were evaluated using one way ANOVA and principal component analysis. Routine swimming, total distance and burst swimming showed significant decrease (IVM 2). IVM impairs swimming activity and displacement that might have direct effects on fitness and consequences at population level.