The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Poecilia kykesis
Poecilia kykesis
(Péten molly)

Copyright Info
Poecilia kykesis Poeser, 2002

Common name: Péten molly

Synonyms and Other Names: Molliensia petenensis, Poecilia petenensis, swordtail molly, spiketail molly

Taxonomy: available through www.itis.govITIS logo

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
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

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.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
FL197119742Everglades; Tampa Bay

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.

Remarks: Males of this species are characterized by a sail-like dorsal fin, similar to that of P. latipinna, and a short sword in the caudal fin (Dawes 1991). This species was formerly designated as P. petenensis, but was reassigned to P. kykesis because of nomenclatural problems (Poeser 2002). True P. petenensis Günther, 1866, formerly placed in synonymy with P. sphenops, appears restricted to Lake Petén (Poeser 2002).

Voucher specimen: UF 138406.

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.

Other Resources:
FishBase Summary

Author: Leo Nico, and Matt Neilson

Revision Date: 11/14/2012

Peer Review Date: 11/14/2012

Citation Information:
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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2022]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [5/26/2022].

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