Mangrove Rivulus


Mangrove rivulus: Rivulus marmoratus

Taxonomic Classification

Kingdom: Animalia
Phylum: Chordata
Class:  Actinopterygii 
Order: Cyprinodontiformes
Family: Rivulidae
Genus/Species: Kryptolebias marmoratus
Common Name: Mangrove rivulus

Listing Status

Federal Status: Not Listed
FL Status: No longer listed in Florida as of January 11, 2017, but is part of the Imperiled Species Management Plan.
FNAI Ranks: Not ranked
IUCN Status: LC (Least Concern)

Physical Description

Mangrove rivulus are the only member of the rivulus family that occurs in North America (Taylor and Snelson 1992).  This species can reach a body length of 2.4 inches (6.1 centimeters).  Mangrove rivulus are olive-colored with a flat back body, rounded tail fin, and small black dots located throughout the body surface (sometimes) (National Oceanic and Atmospheric Association 2009).

Life History

The diet of the mangrove rivulus primarily consists of worms, copepods (small crustaceans), mosquito larvae, and their own eggs when held captive (National Oceanic and Atmospheric Association).

Mangrove rivulus are self-fertilizing hermaphrodites (have both male and female reproductive organs), which makes them the only known vertebrate to practice this style of reproduction.  However, a small non-hermaphroditic population has been discovered in Belize.  Eggs hatch two to four weeks after being laid (National Oceanic and Atmospheric Association 2009). 

Habitat and Distribution

Mangrove Rivulus Distribution MapThe mangrove rivulus inhabits mangrove forests from southeastern Brazil through the Antilles and Central America to Florida (Taylor 1999).  In Florida, this species is found on the Atlantic coast from the Keys to Volusia County and from the Keys to Tampa Bay on the Gulf Coast (Taylor 1999, Briggs and Brown 1986, S. Taylor pers. comm. 2012).  They are an amphibious/fossorial species (they are capable of living on land and water, burrowers on land).  Most of their time is spent on land where they can be found hidden in rotten wet logs or under moist leaf litter (Taylor et al. 2008).                                                    


The main threat to the mangrove rivulus is the destruction and fragmentation of mangrove habitat caused by development, encroachment, and mosquito control (National Oceanic and Atmospheric Association 2009).  Other threats include habitat pollution from pesticides (Taylor 1999).

Conservation and Management

The mangrove rivulus is protected from take by 68A-4.001, F.A.C.

Florida’s Endangered and Threatened Species Rule External Website.

Biological Status Review (BSR) Adobe PDF
Supplemental Information for the BSR Adobe PDF

Species Action Plan Adobe PDF

Other Informative Links

International Union for Conservation of Nature  External Website
National Oceanic & Atmospheric Administration  External Website
Smithsonian Marine Station at Fort Pierce External Website



Printable version of this page Adobe PDF


Briggs, J. C. and Brown, J. E. 1986. Effect of reditching mosquito control ditches on the fish community of the mangrove habitat in Tampa Bay, Florida. Report to Pinellas County Mosquito Control District. 10 p.

National Oceanic and Atmospheric Association. (2009). Mangrove rivulus. Retrieved April 21, 2011, from NOAA National Marine Fisheries Service.

Taylor, D. S. 1999. Rivulus marmoratus status review: consideration for listing under the  Endangered Species Act. National Marine Fisheries Service. Final Report. 46 p.

Taylor, D. S., Turner, B. J., Davis, W. P., and Chapman, B. B. 2008. A novel terrestrial fish habitat inside emergent logs. American Naturalist 171(2):263-266.

Image Credit FWC

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