This species was included in the genus Aphanius prior to 2020 (Freyhof and Yoğurtçuoğlu 2020).

The Baetican Killifish is endemic to Spain where it is has a restricted range (area of occupancy (AOO) c. 260 km²), which meets the threshold for the Endangered category under Criterion B2 (AOO < 500 km²), and the extent and quality of habitat are estimated to be declining, driven by water abstraction, pollution, artificial modification and drought. However the population is not considered to be severely fragmented and it occurs at at least 15 locations.

Therefore, this species is assessed as Near Threatened (B2b(iii)) as it is close to qualifying as Vulnerable under Criterion B.

This species is restricted to the lower Guadalquivir River drainage and small coastal streams in the provinces of Sevilla and Cádiz, Andalusia, southern Spain.

It has been introduced to single sites outside of its natural range in Cádiz and the adjacent province of Huelva.

This species' current population size is believed to exceed 10,000 mature individuals, while its ongoing population trend has not been quantified. Genetic variability within and between the identified subpopulations is very low.

As of 2022, an introduced subpopulation formerly established at Tarifa (Cádiz) appears to have been extirpated due to habitat modification (M. Ford, pers. comm.)

This species is euryhaline and inhabits freshwater to hypersaline lagoons, tidal channels, the lower reaches of small rivers, tributary streams and artificial salt pans. Aquatic vegetation is mostly sparse, and substrates comprise silt or mud.

Many of its habitats undergo significant inter-seasonal or inter-annual fluctuations in abiotic factors such as salinity, temperature and water-level. For example, many streams within its range largely dry out during summer and autumn, with the fish surviving in disconnected remnant pools which function as refugia until flow is restored after heavy rainfall. The number of individuals in each subpopulation can therefore fluctuate significantly on an annual basis, depending on environmental conditions.

This species is a fractional spawner, reproducing throughout the spring and summer. It exhibits early sexual maturity and rapid growth, both of which are considered adaptations to unstable environments.

It is omnivorous, with the diet dominated by detritus plus small invertebrates such as copepods, amphipods and chironomids.

This species is threatened by habitat degradation driven by water abstraction, pollution, artificial modification and drought.

The widespread introduction of non-native fish and crustacean species, particularly Common Carp (Cyprinus domestic strain), Eastern Mosquitofish (Gambusia holbrooki), Mummichog (Fundulus heteroclitus) and Red Swamp Crayfish (Procambarus clarkii) is also a concern, since all are considered invasive and can exert detrimental pressures on native freshwater fauna through increased competition, depredation or habitat degradation.

Some of its habitats are entirely surrounded by intensive agriculture, while livestock grazing during dry months of the year is responsible for the accumulation of potentially harmful nitrogenous waste into refuge pools since the animals use them for drinking and bathing.

It is plausible that its habitats could be adversely affected by extended periods of dry weather driven by climate change.

This species is not used or traded.

This species is included (originally as Aphanius iberus) in Appendices II and III of the Bern Convention and Annex II of the European Union Habitats Directive.

It is also listed in Regional Andalusian Law 8/2003 which covers conservation of flora and fauna. It is included in both national and regional red lists of threatened species, and several subpopulations occur within the boundaries of protected areas, including Doñana National Park and several sites included in the European Union's Natura 2000 network.

From 2007-2011 it was the subject of a conservation plan financed by the Andalusian regional authority, during which management actions at selected sites including habitat restoration, creation of new refuge zones, removal of alien species, fencing of sites subjected to pressure from livestock and introduction of new populations.

Ex situ reproductive populations are maintained at El Acebuche Visitor Centre in Doñana National Park, and the University of Córdoba.

Regular subpopulation monitoring should ideally be carried out in order to assess ongoing trends.