Fundulidae is the family of topminnows and (mainly) North American killifish

Killifish

A killifish is any of various oviparous cyprinodontiform fish . Altogether, there are some 1270 different species of killifish, the biggest family being Rivulidae, containing more than 320 species...

es. The 46 species are native to North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 as far south as Yucatan

Yucatán

Yucatán officially Estado Libre y Soberano de Yucatán is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 106 municipalities and its capital city is Mérida....

, and to the islands of Bermuda

Bermuda

Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...

 and Cuba

Cuba

The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

, occurring in both freshwater and marine environments.

Members of the family are all small; while the giant killifish Fundulus grandissimus and northern studfish Fundulus catenatus reach 20 centimetres (7.9 in) in length, but most species are under 10 cm.

The distinguishing characteristic of the family is the maxillary bone, which is twisted instead of being straight.

Species

FishBase

FishBase

FishBase is a comprehensive database of information about fish species . It is the largest and most extensively accessed online database on adult finfish on the web...

 lists 45 living and one recently extinct species in four genera:

• Genus Adinia
  • Diamond killifish, Adinia xenica (Jordan
    David Starr Jordan
    David Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
    
     & Gilbert, 1882).
  • Adinia multifasciata
• Genus Fundulus
  Fundulus
  Fundulus is a genus of ray-finned fishes in the superfamily Funduloidea, family Fundulidae . They belong to the order of toothcarps , and therein the large suborder Cyprinodontoidei...
  
  (39 living species, 1 recently extinct)
• Genus Leptolucania
  • Pygmy killifish, Leptolucania ommata (Jordan
    David Starr Jordan
    David Starr Jordan, Ph.D., LL.D. was a leading eugenicist, ichthyologist, educator and peace activist. He was president of Indiana University and Stanford University.-Early life and education:...
    
    , 1884).
• Genus Lucania
  Lucania (genus)
  Lucania , is a genus of small ray-finned fishes in the family Fundulidae.-Species:FishBase lists 3 species:* Bluefin killifish, Lucania goodei Jordan, 1880* Cuatrocienegas killifish, Lucania interioris Hubbs & Miller, 1965...
  
  (3 species)