Aphanius Fasciatus

– Mediterranean Killfish –

The Mediterranean killifish, Mediterranean banded killifish or South European toothcarp (Aphanius fasciatus) is a species of fish in the family Cyprinodontidae. It is found in Albania, Algeria, Bosnia and Herzegovina, Croatia, Cyprus, Egypt, France, Greece, Israel, Italy, Lebanon, Libya, Malta, Morocco, Montenegro, Slovenia, Syria, Tunisia, and Turkey. Its natural habitats are saline lakes, saline marshes, and coastal saline lagoons.

Distribution

This specie is well-distributed around central and western parts of the Mediterranean coastline, including the Adriatic Sea, and has been recorded from the countries of France, Italy, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania, Greece, Turkey, Syria, Lebanon, Israel, Egypt, Libya, Tunisia and around the islands of Sardinia, Corsica, Sicily and Malta. 

There are also a handful of inland freshwater populations, most notably in Lake Bafa, Turkey (although this is gradually becoming saline) and some oases of western north Africa. In the Egyptian oasis at Siwa it apparently occurs sympatrically with A. dispar.

The fish exhibit notable variations in colouration and patterning depending on locality. It is therefore important that the different forms be labelled with the collection details by hobbyists and scientists alike in order to preserve bloodlines and maintain accuracy e.g. “Lake Bafa”, “Saline di Cervia” etc. While it is not currently at risk of extinction at species level many individual populations are sadly threatened for various reasons.

Habitat

Found in numerous habitat types although it mostly inhabits shallow coastal waters such as lagoons, salt marshes and first order streams in areas where submerged vegetation and/or filamentous algae grow thickly. It is highly adaptable and tolerant of a wide range of salinities from pure freshwater to hypersaline conditions. For example near the town of El Agheila in Libya it inhabits warm springs containing high levels of calcium sulfate and hydrogen sulfide making them inhospitable to other fish species.

Like most Aphanius it is being outcompeted by Gambusia and other introduced species across some parts of its range while habitat degradation and pollution continue to affect others; some populations have probably been wiped out already and studies suggest the situation is only likely to deteriorate in the future.

Aquarium Size

A pair or trio can be kept in a container with base dimensions of 60 cm x 30 cm or so but as a general rule members of this genus do best when maintained as a larger group in a space measuring upwards of [dimensions]. It is advised to find a filter which has a water flow between 4-5 times the volume of your aquarium. At a volume of 108 litres, the filter we recommend can be found here. Other aquarium filters which have been recommended highly by customers in your area can be found here.

Maintenance

Even for long-term maintenance a simple set-up will suffice. The most important factors are the provision of many broken lines of sight and a suitable medium in which the fish can deposit eggs. Female and subdominant male individuals must be offered the opportunity of respite from the aggressive alpha males during the spawning season so much of the available space can be filled with acrylic wool mops (use a fine grade if available), clumps of java moss or Ceratophyllum and ideally filamentous algae. There is no need to add a substrate although inert sand or gravel can be added if you preferand filtration need not be too strong either.

It is possible, and preferable, to maintain it outdoors all year round in many countries and it will show better colours and overall condition if exposed to at least a few hours of natural sunlight each day. Try to find out the origin of your fish as some populations will do best in freshwater but if in doubt we recommend the addition of marine salt in the ratio of 1-3 g/L as most will need it. Those from hypersaline locations are likely to require concentrations in excess of 20 g/L in order to breed.

Water Conditions

Temperature: Active over a wide temperature range of 2 – 30 °C. Artificial heating is not required in all but the coldest climates and it should be provided with a ‘winter’ period of several months during which it is maintained at low temperatures or it is likely to suffer both reduced fecundity and a shortened lifespan. 

Hotter conditions are tolerated, at the Messolongi coastal lagoon in Greece the water temperature was recorded at 104°F/40°C in July, but we don’t recommend maintaining the fish like this for any period of time in aquaria because in nature they experience a daily fluctuation depending on the position of the sun.

pH: 7.5 – 9.0. It will probably not survive under acidic conditions.

Hardness: 179 – 536 ppm Click here to find the heater we recommend for an aquarium of this size. To search for other high quality aquarium heaters in your area, click here.

Diet

Aphanius species are basically micropredators feeding on small aquatic crustaceans, worms, insect larvae and other zooplankton although algae and other plant material is also taken at times. 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 or bloodworm. This is particularly important during the months of spring and summer due to their high reproductive effort throughout this period. If the aquarium or container does not contain filamentous algae try to introduce a good quality dried product with added Spirulina content to the diet. Click on the following links to search for high quality live, frozen and dry food: Bloodworm, Artemia, Daphnia. To find other high quality, highly recommended foods click here.

Behaviour and CompatibilityTOP ↑

Its particular water requirements make A. fasciatus a poor choice for the community aquarium. Given its rarity in the hobby the emphasis should also be on captive reproduction and we strongly recommend maintaining it alone. It should be kept in a group with a ratio of two or three females to each male being the ideal.

Sexual Dimorphism

As with all members of the genus sexual dimorphism is pronounced. Males exhibit a series of 8-15 blue/greyish vertical bars on the flanks. The anal fin usually contains some dark streaking and the dorsal some spot-like markings near the base and the finnage in general is usually a yellow/green colour. Females are larger and much plainer possessing only a series of brown vertical bars on the body (which the occasional specimen may lack) along with some irregular dark spotting above the lateral line and completely hyaline finnage.

Depending on the population the number and width of the vertical bars in males can vary and there may or may not be a dark submarginal band in the caudal fin.

Reproduction

Captive reproduction is not difficult if the tank or container is properly arranged and maintained (see ‘tank set-up’). It is a fractional spawner with females depositing eggs on a more-or-less continuous basis between the months of April and September. Males form temporary territories which they defend against rivals while attempting to entice females to spawn. Dominant individuals will show more intense colouration. Eggs are released singly or in small batches and are attached to algae or other surfaces by means of small filaments. Aphanius typically eat their eggs/fry and the medium should therefore be checked on a daily basis during the spawning period.

The eggs are very small and must be treated carefully. Use a fine pair of forceps to gently remove pieces of medium with eggs attached whilst avoiding contact with the eggs themselves. Alternatively the entire medium can be removed and replaced every couple of days. The medium/eggs should be transferred to a container with water of the same chemistry and temperature as that of the adults. The incubation period can vary a little with the temperature but is usually between 10 – 15 days with the fry being large enough to accept Artemia nauplii, microworm etc. immediately after they become free-swimming.

From Wikipedia, the free encyclopedia