Kryptolebias marmoratus, (Poey, 1880)


This species was first described by Poey as Rivulus marmoratus but W. Costa (2004) moved them into the new genus Kryptolebias based on typical ostelogical characteristics. Hensel 1868 published the description of Kryptolebias (than known as Rivulus) ocellatus which was seen by many scientist as synonyme to Kryptolebias marmoratus that was described later in 1880. But, if both species would be really the same ... Kryptolebias marmoratus should not have the status of synonymy to Kryptolebias ocellatus but the other way around . Costa (2006) revised the group and found several meristic and osteologic differences between Kryptolebias marmoratus and Kryptolebias ocellatus and for this reason he gave Kryp. ocellatus the status of valid species next to Kryptolebias marmoratus.

First discovery of this scientific very ancient species was by D. Rafael Arango. Poey used the name Rivulus marmoratus in reference to the marbled (latin = marmoratus) red stains he saw at the males sides.

The type locality was Cuba but the species can be found in marin marches and mangrove biotopes all over the islands of the caraibben sea including the shore- areas of southern North America, east coast of Middle America and coastline of northern South America. More to the east along the coast of South America, the species changes in colour pattern and by that some scientists described these color variations as new species.

Kryptolebias marmoratus - "primary" male. Terra Cein - Florida, USA. Image made by F.Vermeulen.
Kryptolebias marmoratus - hermafrodite. Terra Cein, Florida, USA. Image made by F.Vermeulen.

Here we consider names as : K. bonairensis, K. heyi as synonymes till more rechearch is done to prove these are valid or not. Taking DNA from all the species in the group could make things more clear in the future.

See also Kryptolebias ocellatus page and the <introduction> page on the genus Kryptolebias.

I believe a species like Rivulus roloffi needs to be examined to find out if they are Kryptolebias as well.

Look at the small movie from Scott Taylor as he breaks open a log in K. marmoratus - land. Amazing footage send to me by Prof. Bruce Turner, USA. I like to thank both scientists for their effort to help me with all kind of written material and this short fotage.

PDF click this !


Reproduction is unique as K. ocellatus and K. marmoratus are the only fishes that can produce fertile eggs by a single hemafrodite female as the result of self fertilasation.. Reproduction can also occur by fertilasation by primary males that evolved under extreme bad environmental conditions. Eggs develop between 14 and 16 days, sometimes can get spawned a few days after fertilasation itself or as embryonal development is in a furder stage.


The species is known to be able to survive even dry periods of months in hollow moisture trees. They live in crabholes at the outer edges of marine enviorments and temporary marine swamps that are affected by the daily tidal change of sea level.


Kryptolebias marmoratus - hermafrodite. Terra Cein, Florida, USA. Image made by F.Vermeulen.
Kryptolebias marmoratus - hermafrodite. South Florida, USA. Image made and donated by Tony Pinto, USA.




Max. size 7.5 cm.
Dorsal 8.6,
Anal 11.2,
D/A 0.0,
LL scale count (average)47.3
Pre- dorsal length to % SL – 76.8 %
Depth to % SL – 19.9 %



Poey, F. 1880. Revisio piscium cubensium. Anal. Soc. Espanola Hist. Nat., 9: 248.

Costa, W.J.E.M., 2006. Redescription of Kryptolebias ocellatus and Kryptolebias caudomarginatus. PDF right-click to open in new window!

Bruce J. Turner,1* Michael T. Fisher,1‡ D. Scott Taylor,2
William P. Davis3 and Bambi L. Jarrett1. 2006. Evolution of ‘maleness’ and outcrossing in a population of the self-fertilizing killifish, Kryptolebias marmoratus. PDF right- click to open in new window!

Edenbrow M. & D.P. Croft. 2012. Sequential Hermaphroditism and Personality in a clonal Vertebrate: The Mangrove killifish. Behavioural Processes, Volume: 90, Issue: 2: 229-237.

LeBlanc, D.M., M. Wood, S. Douglas, A. Wright.   A Fish Out of Water: Gill and Skin Remodeling Promotes Osmo- and Ionoregulation in the Mangrove Killifish Kryptolebias marmoratus. marmoratus (Kryptolebias) Physiological and Biochemical Zoology, 83 (6): 932-949,