Common name: Péten molly
Synonyms and Other Names: Molliensia petenensis, Poecilia petenensis, swordtail molly, spiketail molly
available through www.itis.gov
Identification: This species is part of the Poecilia latipinna complex. Distinguishing characteristics and identification keys that include this species were given by Miller (1983) and Greenfield and Thomerson (1997). In general, it can be distinguished from other species in the sailfin molly complex (P. latipinna and P. velifera) by the number of scales around the caudal peduncle, lateral line scales, and number of dorsal fin rays (table below derived from Miller 1983):
| Species || Scales around caudal peduncle || Lateral scales || Dorsal fin rays |
| P. kykesis || 20 || 28-29 || 12-16 |
| P. latipinna || 16 || 25-29 || 12-16 |
| P. velifera || 20 || 26-27 || 16-21 |
A photograph appeared of this species appeared in Wischnath (1993).
Size: Females 10 cm; males 13 cm.
Native Range: Middle America from southeastern Mexico to Belize and Guatemala (Miller 1983; Greenfield and Thomerson 1997).
Hydrologic Unit Codes (HUCs) Explained
Puerto Rico &
Interactive maps: Point Distribution Maps
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Poecilia kykesis are found here.
Table last updated 5/26/2022
† Populations may not be currently present.
Ecology: Poecilia kykesis, similar to other species in the Poecilia latipinna complex, occurs in shallow, brackish to freshwater coastal areas such as tidal lagoons, lakes, creeks, and pools. It is found across a range of turbidity (clear to muddy) and substrate types (mud, sand, clay) and is sometimes associated with submerged or emergent aquatic vegetation (Miller et al. 2005)
Means of Introduction: Probable aquaculture escape or aquarium release.
Status: This molly has been reported from Florida. It has been suggested that introduced populations may have survived for brief periods and possibly reproduced but did not succeed as no established populations are known (Courtenay et al. 1974).
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Courtenay, W. R., Jr., H.F. Sahlman, W.W. Miley, II, and D.J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6(4):292-302.
Greenfield, D.M., and J.E. Thomerson. 1997. Fishes of the continental waters of Belize. University Press of Florida, Gainesville, FL.
Dawes, J.A. 1991. Livebearing fishes. A guide to their aquarium care, biology, and classification. Blandford Press, London, England.
Miller, R.R. 1983. Checklist and key to the mollies of Mexico (Pisces: Poecilidae, Poecilia, subgenus Mollienesia) Copeia 1983(3):817-822.
Miller, R.R., W.L. Minckley, and S.M. Norris. 2005. Freshwater fishes of Mexico. The University of Chicago Press.
Poeser, F.N. 2002. Poecilia kykesis nom. nov., a new name for Mollienesia petenensis Günther, 1866, and redescription, revalidation and the designation of a lectotype for Poecilia petenensis Günther, 1866 (Teleostei: Poeciliidae). Bijdragen tot de Dierkunde 70(4):243-246.
Wischnath, L. 1993. Atlas of livebearers of the world. TFH Publication, Inc., Neptune City, NJ.
Leo Nico, and Matt Neilson
Revision Date: 11/14/2012
Peer Review Date: 11/14/2012
Leo Nico, and Matt Neilson, 2022, Poecilia kykesis Poeser, 2002: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=862, Revision Date: 11/14/2012, Peer Review Date: 11/14/2012, Access Date: 5/26/2022
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.