Endler's Livebearer ( ELB )

The "Cumana guppy"

Heather J. Alexander - Graduate - PhD Department of Biological Sciences on the Canadian Simon Fraser University 2007 graduated on the thesis: Population differentiation and sexual isolation among Poecilia reticulata populations.

She concluded that there was "no evidence of genetic incompatibility" between ELB ( Endlers Live Bearer ) and Poecilia reticulata ( Guppy ) . Also was found that the population in Cumana has had DNA introgressed ("hybridized") from regular guppies.

However the differences between the fysical appereance of the males of both variations are that big that it looks that this could be a different species and/or subspecies, and although the latest thesis ( 2007 )of Alexander e.a. seems to confirm this, basically the suggestion is made that this fish is a geographical race of guppy, and so named according to the geographic location as Cumana guppy. Its not been thought of as a species by Alexander and Breden.

For her PhD-thesis she made a thorough survey of an approximately 100 km radius around Cumana, Venezuela, in more than 20 rivers and canals including all adjacent drainages in 2000 and 2001, together with ( among others..) her promotor Felix Breden.
Only in three locations West of the City of Cumana she could find the typical Endler-variant. The original location where Prof. Endler did his discovery is not mentioned in her thesis..

An array of males retrieved from a single population of the Cumaná guppy ( Collected from the Rio Manzanarez ) reveals the diversity of male coloration in these fish, which is controlled by more than 40 sex-linked loci.

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