Aphanius fasciatus Breeding Guide

Breeding the Mediterranean killifish Aphanius fasciatus: a brackish-tolerant seasonal spawner that lays eggs on the bottom and submerged plants.

Overview

Aphanius fasciatus, the Mediterranean killifish (family Aphaniidae), ranges across the Mediterranean basin from Europe (France, Italy, the Balkans, Greece, Turkey) to North Africa, where FishBase and Wikipedia report it from coastal lagoons and hypersaline to fresh, still or slow-flowing waters. It tolerates salt, brackish and fresh water and the IUCN lists it as Least Concern (2022).

Sexing

Wikipedia notes males reach about 5.5 cm and females up to 6 cm, with males showing 10-15 broad dark transverse bands on olive-green-bluish flanks and females more subtly coloured with indistinct narrow bands.

Conditioning

Maturity is reached by the end of the first year (Wikipedia). The species suits cooler water; FishBase lists 10-24 C (optimum near 18.9 C), pH 6.5-7.5 and 8-10 dH. Condition adults on small live and frozen foods in slightly brackish hard water.

Breeding Setup

A cool, slightly brackish biotope tank with a sandy bottom and submerged vegetation provides the spawning sites this species uses. Fine-leaved plants and algae give the females places to attach eggs.

Spawning Behaviour & Trigger

Spawning is seasonal, running from April to September (FishBase). FishBase notes spawning takes place on the bottom and in submerged vegetation, and Wikipedia adds that females lay their eggs on the bottom, preferably on aquatic plants and algae.

Egg & Fry Care

Wikipedia gives incubation of 10-15 days until hatching. Eggs can be left on the substrate and plants in a low-predation tank or moved for separate incubation; free-swimming fry take small live foods.

Common Challenges

FishBase notes the species can be difficult to maintain. Cool, stable, slightly brackish hard water and protection of eggs and fry from adult predation are the main keys to consistent fry production.