 Spotfin killifish have a diet similar to the mummichog, consisting of detritus, diatoms, foraminiferans, rotifers, insects (dipterans–including mosquitoes and larval chironomids, homopterans, coleopterans, hymenopterans, lepidopterans, odonates, and hemipterans), collembolans, arachnids (spiders, pseudoscorpions, and acarina), crustaceans (copepods, tanaids, ostracods, cladocerans, isopods, and amphipods), annelid worms, mollusks (gastropods), and fish eggs.Fundulids in general are known for high tolerance to extreme environmental fluctuation of parameters including temperature, salinity, and dissolved oxygen.In the wild, "F. luciae" have been collected in salinities ranging from 0–46 ppt, although medium to high salinities are preferred.