A new species of livebearer from the poeciliid genus Priapella has been described from Mexico.
Manfred Schartl, Brigitta Wilde and Manfred Meyer of the University of Wurzburg named the new species as Priapella chamulae in a paper in the latest issue of the journal Zoologische Abhandlungen Dresden.
The new livebearer was found in various parts of Tabasco, Mexico, including the Rio Tacotalpa and Rio Pichucalo on the border of Tabasco and Chiapas, where it occurs in a small gravel-bottomed fast-flowing brook about 50-100cm/20-39" wide.
The water in the stream was crystal clear, warm and alkaline with a temperature of 26°C, a pH of 8.0 and a conductivity of 360mS (around 10-15°GH).
P. chamulae is large for the genus, with a maximum stated size of just under 5cm/2", and has a predominantly silver-beige base colour with a yellowish ventral surface.
It can be distinguished from other Priapella via a range of characters including its short gonopodium which has a membranous hook on the third ray and is bent semicircularly, as well as a number of other features:
"P. chamulae is also distinguished by the following unique combination of characters: length of gonopodium short; frequency distribution of SL/GL radius 3.30-3.50, vs. 2.60-2.75 in P. olmecae, 3.00-3.20 in P. compressa, 2.60 in P. bonita and 3.50-3.60 in P. intermedia; 10 to 12 gill rakers, vs. 15-16 in P. bonita, 12 to 13 in P. compressa, 12 to 14 in P. compressa; 9 dorsal fin rays, vs. 8 in P. bonita, 10 in P. compressa."
For more information on the new species see the paper: Schartl M, Meyer MK and B Wilde (2006) - Description of Priapella chamulae sp. n. - a new poeciliid fish from the upper rio Grijalva system, Tabasco, Mexico (Teleostei: Cyprinodontiformes: Poeciliidae). Zoologische Abhandlungen Dresden. 55: 59-67.