A single male of the Tequila Splitfin was sampled in 1955 by Miller and Greenbank, but identified erroneously as Zoogoneticus quitzeoensis, with which species it was collected and found sympatrically . Many years later, the mistake was detected, the fish identified as a new species and finally, 43 years after the first capture, described by Webb and Miller.

In 2001, a wild population of this species was rediscovered in a very small spring pool (3 x 4m in diameter). The population there was composed of only a handful of adult fish and a few tens of juveniles (De la Vega-Salazar et al., 2003). In 2007, N. W. Bailey et al showed, that the allelic richness of this population (though it was comparable in size to an aquatic stock) was higher than in any aquatic stock. In 2013 the loss of this population was reported (pers. comm. Domínguez), so there is not much hope that this species is still persisting in the wild.

Occurs naturally in Brazil, Paraguay, Uruguay and Argentina with feral populations in Australia, New Zealand, Ethiopia and Malawi which were purportedly introduced for purposes of mosquito control but are now considered invasive.

Following Lucinda (2008) its natural range comprises the Lagoa dos Patos system, lower rio Uruguai, rio Tramandaí, and rio Mampituba in Rio Grande do Sul st…

Endemic to the Río Atrato drainage in Choco and Antioquia departments, northwestern Colombia, where the full extent of its range is somewhat unclear.

Type locality is ‘Río Truandó, a tributary of Lower Río Atrato, Colombia’, and it may be restricted to that system.

This species has a somewhat confusing taxonomic history and it remains unclear whether it is conspecific with S. izecksohni (Da Cruz, 1983) or not.

The latter is considered to represent a synonym of S. myersi by Costa (2007), but the majority of authors do not follow the conclusions of that study (see below) and continue to view both as valid.

Tends to be most common in brackish to hypersaline environments such as coastal salt marshes, lagoons and estuaries.

On San Salvador Island, Bahamas, it appears to be the parent of a species group occurring in sympatry and exploiting diverse but specific resources with some spectacular morphological adaptations.

Endemic to San Salvador Island in the Bahamas where it’s known from six hypersaline lakes; Crescent Pond, Osprey Lake, Oyster Lake, Little Lake, Wild Dilly Pond and Moon Rock Pond.

Type locality is ‘San Salvador Island, Bahamas: Crescent Pond, 1 km SE of the Gerace Research Centre, lat 24°06’45″N, long 74°27’28″W’.

This species is a specialised lepidophage with approximately 50 % of the diet comprising the scales of other fishes.

Physical adaptations to this behaviour include its elongate body and jaw mechanism permitting a fast biting action.

The surrounding area is semi-arid and the Bolsón de Sandia was once a beautiful oasis with a number of springs, abundant vegetation and diverse wildlife but has dried up over the last twenty to thirty years due to indiscriminate water extraction for agriculture and other human uses.

Three endemic species of Cyprinodon, namely C. veronicae, C. longidorsalis and C. ceciliae, have been described from separate springs within the system…

Need not be too complicated so long as there are plenty of broken lines-of-sight.

Provide plenty of cover in the form of aquatic plants, wool mops, etc., and if using filtration air-powered, sponge-type units are best as these will not harm eggs or fry.

Lighting is unimportant but can be use…

El Pandeño de los Pando has a surface area of around 287 m² with depth ranging from 40-80 cm but there is an abandoned artificial channel which has an area of approximately 437 m².

Water temperature fluctuates between 38-48°C/100.4-118.4°F and the spring is considered one of the hottest environments inhabited by fish in the world.