Mediterranean Killifish

The Mediterranean killifish is a small killifish that lives in the coastal lagoons, salt pans and estuaries of the Mediterranean; it is also found on the Aegean and Mediterranean coasts of Türkiye. It is known for tolerating environments whose salinity ranges from fresh water to several times that of seawater. Males are recognized by their bodies with dense dark vertical bands and their yellow-orange fins, females by their larger, spotted bodies. It is among the protected species in Europe; the draining of coastal wetlands and the invasive mosquitofish are the main threats. It should not be collected from the wild, nor released into the wild.

• At least 60 liters for a group of 4–6.
• Brackish water is ideal: a salinity of roughly a quarter to a half of seawater; the transition to fresh water should be made slowly.
• No heater is needed; 22–26°C in summer, and cooling down in winter is natural.
• Salt-tolerant plants or rocks, good lighting, a tight lid.

Omnivorous. In the wild it eats small crustaceans, insect larvae and algae. In the aquarium it is fed brine shrimp, mysis shrimp, daphnia and spirulina flakes.

Males are territorial; they chase each other and are persistent towards females. A divided layout reduces tension. It lays its eggs on plants or algae.

Good companions: a group of its own species; calm species suited to brackish water.

Avoid: freshwater community fish (salt incompatibility), other toothcarp species (hybridization), large and aggressive fish.