Mangrove rivulus

Rivulus
Conservation status
Least Concern (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cyprinodontiformes
Family:	Rivulidae
Genus:	Rivulus
Species:	R. marmoratus
Binomial name
Rivulus marmoratus Poey, 1880

The mangrove killifish or mangrove rivulus, Kryptolebias marmoratus (formerly Rivulus marmoratus)^[1], is a species of fish in the Aplocheilidae family. It lives along the east coast of North, Central and South America, from Florida to Brazil. It is about 75 mm long.

The mangrove rivulus is a U.S. National Marine Fisheries Service Species of Concern. Species of Concern are those species about which the U.S. Government’s National Oceanic and Atmospheric Administration, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act (ESA).

Ecology

Scientists have recently discovered that Mangrove rivulus can spend up to sixty-six consecutive days out of water, which it typically spends inside fallen logs, breathing air through its skin.^[2] It enters burrows inside the trees created by insects where it relaxes its territorial, aggressive behavior. During this time it alters its gills so that it can retain water and nutrients, while nitrogen waste is excreted through the skin. The change is reversed once they re-enter the water.^[3][4]

The species consists mostly of hermaphrodites which usually reproduce by self-fertilisation, but males do exist,^[5] and there is strong genetic evidence for occasional outcrossing.^[6]

Conservation

This species is extremely vulnerable to habitat modification and fragmentation, environmental alteration, and human development/encroachment.

Conservation designation

• IUCN: Least Concern
• American Fisheries Society: Vulnerable
• Species of Greatest Conservation Need: Florida

Status reviews

Taylor (1999) is the last status review for the species.

See also

• Walking catfish
• Climbing perch
• Androdioecy

References

1. ^ Ong, K. J.; Stevens, E. D.; Wright, P. A. (2007). "Gill morphology of the mangrove killifish (Kryptolebias marmoratus) is plastic and changes in response to terrestrial air exposure". Journal of Experimental Biology 210 (7): 1109. doi:10.1242/jeb.002238.  edit
2. ^ "Tropical fish can live for months out of water", Reuters, Wed Nov 14, 2007 9:05pm GMT
3. ^ "The fish that can survive for months in a tree", Daily Mail, 17 October 2007
4. ^ "Tropical fish can live for months out of water", Reuters, Wed Nov 14, 2007 9:05pm GMT
5. ^ Lublnski, B.A.; Davis, W.P.; Taylor, D.S.; Turner, B.J. (1995). "Outcrossing in a Natural Population of a Self-Fertilizing Hermaphroditic Fish". The Journal of Heredity 86 (6): 469-473. http://jhered.oxfordjournals.org/content/86/6/469.full.pdf. 
6. ^ MacKiewicz, M.; Tatarenkov, A.; Turner, B. J.; Avise, J. C. (2006). "A mixed-mating strategy in a hermaphroditic vertebrate". Proceedings of the Royal Society B: Biological Sciences 273 (1600): 2449. doi:10.1098/rspb.2006.3594.  edit

External links

• IUCN Red List: Rivulus marmoratus.
• Froese, Rainer, and Daniel Pauly, eds. (2006). "Kryptolebias marmoratus" in FishBase. April 2006 version.
• NMFS: Species of Concern Fact sheet
• Grupo Rivulus