 The genus Austrofundulus, |
Austrofundulus Myers, 1932 was erected in the description of A. transilis. The name is a combination of the terms "Austro" , which means "southern", and the North American genus Fundulus.
Austrofundulus spp. live in dry mostly open areas along the northern coast from Venezuela, more inland close to rivers connected to the Orinoco and the northern part of Colombia. The genus is often found sympatric with members of the genus Rachovia, Gnatholebias and Rivulus. For those who go out and collect species from this genus it is best to know that these live in murky waters and never in clear pools.
Austrofundulus is closely related to Rachovia. However, according to Hrbek et al. (2006), and www.killi-data.org, they differ in several ways.
In any case they differ by their overall appearance, their behavior and life cycle. Besides these major differences there are some features which are seen in Rachovia only, like there are: the dark pigmented genital papillae and the dark colored spot just behind the gill cover.
In his revision of the genus Hrbek et al. (2005) described a remote southern component in the Rupununi savannah in the Cooperative Republic of Guyana. This new described taxon with the name Austrofundulus rupununi occurs far away from all other Austrofundulus in temporary waters that are connected during floods to the Rio Takatu, and thus to Rio Branco, a major tributary of the Amazon River.
This Rupununi species, and three more components were added to the three known species at that time. This brings the total of species to seven. The distribution seems however sometimes overlapping at many places and it is not easy to recognize which species you have at hand without a proper diagnostic evaluation or better a DNA- sequence.
Costa recently proposed to "lump" Austrofundulus with Rachovia based on assumptions that nobody can understand or verify. Despite Costa's own doubts about this "lump" Costa prefers to propose this anyway. Based on earlier DNA research and personal investigations regarding the remarkable differences in life cycle, behavior and appearance in both genera we cannot follow Costa's move herein.
Behavior:
Austrofundulus becomes rather robust, and males can be very aggressive to each other and to females. They are not difficult to breed but breeders need patience because the eggs need a period of 2-12 months to develop. Only very high (30-35C) incubation temperatures, with a very moist medium, can force some of the eggs to develop in 4 weeks. Normally the male and female dive into the substrate which is soft clay in their natural environment; but if this is too they can also put their eggs on the substratum.