Aplocheilus spp. are surface-dwelling predators preying on both aquatic and terrestrial invertebrates.

In the aquarium they will learn to accept dried foods in most cases but should also be offered regular meals of small live or frozen fare such as Artemia, Daphnia, chironomid larvae (bloodworm), etc.

This species is euryhaline and mostly inhabits lowland, often coastal, habitats containing still or slow-moving brackish or freshwater.

It displays a preference for habitats with surface vegetation or overhanging cover and is commonly found in mangrove swamps and rice paddies.

P. arnoulti has been in the aquarium hobby for many years but was identified as the congener P. omalonotus prior to its description.

It appears in the majority of older aquarium literature under that name and as a result a degree of hybridisation has undoubtedly occurred.

The majority of original populations have already been extirpated due to introduction of invasive species such as Gambusia holbrooki and Poecilia reticulata, ongoing deforestation of the Ambohitra Massif, and physical diversion of the source of the Sakaramy River for domestic use by locals.

An additional population may exist in a stream on the southern slope of the Ambohitra Massif on the road between Bobasokoa and Anivorano, near the village of Andranotohiliny, but this requires verification.

For a number of decades this species was thought to occur throughout much of Madagsacar’s western slope but populations immediately to the north and south of the range described above (see ‘Distribution’) are currently considered to represent unidentified species, while a number of populations from the Mahavavy du Sud and Betsiboka riv…

Type locality is given simply as ‘Seychelles’ and this species was originally endemic to the Granitic Seychelles, i.e., those islands in the centre of the group composed chiefly of granite rock.

A translocated population now exists on Zanzibar while in the Seychelles it’s known from the islands of Mahé, Praslin, Silhouette and La Digue.