Endemic to the islands of Bermuda and listed as a protected species in the Bermuda Protected Species Act 2003. Killifishes were described as abundant and widespread in the wetland communities of Bermuda during the late nineteenth and early twentieth centuries, but are now only found in nine isolated ponds. Two of these populations are F. relictus. Petersen population estimates in 2004 suggested that 8,508 fish were Lover’s Lake and 1,793 fish were in Bartram’s Pond (Ref. 59051). Local populations could include more undescribed Fundulus species (Ref. 35505).

In addition to one naturally occurring Fundulus relictus population in Bermuda, there is one other population living in a man-made pond, (created by dredging), where F. relictus was intentionally introduced in the 1980s as a precaution against a possible extinction event (Ref. 59051). Also Ref. 27139.