Invasive lionfish learn to avoid a “spicy” prey fish — ASN Events

Invasive lionfish learn to avoid a “spicy” prey fish (#403)

Lillian J. Tuttle 1 , Mark A. Hixon 2
  1. Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
  2. Department of Biology, University of Hawaii at Manoa, Honolulu, HI, USA

Invasive red lionfish (Pterois volitans) are voracious, generalist predators of Atlantic coral-reef fishes.  There is concern that lionfish may consume cleaner gobies (Elacatinus spp.): ubiquitous, conspicuous, and ecologically important species that clean parasites off of other reef fishes.  We conducted two laboratory experiments to test whether or not (1) juvenile lionfish and native groupers eat E. genie, and (2) lionfish learn not to eat E. genie, which have a putative skin toxin.  Nearly half of invasive lionfish (n=14 of 31) and native graysby grouper (Cephalopholis cruentata, n=11 of 23) ate E. genie, all of which hyperventilated for several minutes post-consumption.  During the second experiment, most lionfish (n=18 of 24) either successfully ate the goby, or ate it and spit it out immediately, hyperventilating in either case.  After eating E. genie, lionfish experienced elevated ventilation rates over twice as vigorous (mean±SEM = 140.7±1.9 vs. 64.3±1.4 opercular beats/minute) and for 6 times as long (mean±SEM = 11.8±5.4 vs. 1.6±0.2 minutes) as those experienced after eating similarly sized and shaped non-toxic prey (bridled goby Coryphopterus glaucofraenum).  During subsequent exposures of the same lionfish to E. genie over the course of two weeks, lionfish would often approach the goby closely, then turn away without striking.  These data are consistent with those of manipulative experiments conducted on coral patch reefs that found no effect of lionfish on Elacatinus spp. abundance.  Due to their distastefulness, E. genie may be one of the few fishes on Atlantic coral reefs that escape the jaws of invasive lionfish.