Fundulus


Fundulus is a genus of ray-finned fishes in the superfamily Funduloidea, family Fundulidae. It belongs to the order of toothcarps, and therein the large suborder Cyprinodontoidei. Most of its closest living relatives are egg-laying, with the notable exception of the splitfin livebearers.
They are usually smallish; most species reaching a length of at most 4 in when fully grown. However, a few larger species exist, with the giant killifish and the northern studfish growing to twice the genus' average size.
Many of the 40-odd species are commonly known by the highly ambiguous name "killifish", or the somewhat less ambiguous "topminnow". "Studfish" is a quite unequivocal vernacular name applied to some other Fundulus species; it is not usually used to refer to the genus as a whole.
Fundulus have evolved to occupy a wide range of aquatic ecosystems, including marine, estuarine, and freshwater, making it a good comparative model system for studying evolutionary divergence between marine and freshwater environments. To assist with this research, Oxford Nanopore long-read reference genomes have been sequenced for F. xenicus, F. catenatus, F. nottii, and F. olivaceus''.''

Species

There are currently 39 recognized species in this genus:Fundulus albolineatus C. H. Gilbert, 1891 Fundulus bermudae Günther, 1874 Fundulus bifax Cashner & Rogers, 1988 Fundulus blairae Wiley & D. D. Hall, 1975 Fundulus catenatus Fundulus chrysotus Fundulus cingulatus Valenciennes, 1846 Fundulus confluentus Goode & T. H. Bean, 1879 Fundulus diaphanus
The following fossil species are also known:
The Cuban killifish was formerly placed in Fundulus''.