Aphanius fasciatus
Classification
Order: Cyprinodontiformes Family: Cyprinodontidae
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.
Maximum Standard Length
50 – 55 mm.
Aquarium SizeTop ↑
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].
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
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.
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.
NotesTop ↑
A 2003 phylogenetic study by Hrbek and Meyer showed that in genetic terms specimens of A. fasciatus collected from different localities do not vary as much as with other members of the genus. The latter tend to exist in geographically separated populations and exhibit localised differentiation. While A. fasciatus does show certain disparities in appearance depending on locality it is thought that periodic migration events have restricted the development of genetic diversity within the species to some extent.
The only exception was found in fish from Lake Bafa; this population is considered to have diverged from the others around 4 million years ago and is now isolated from the Mediterranean Sea by a mountain range which prevents genetic flow.
You are unlikely to find it on sale in aquatic stores although it may be available via specialist breeders or associations from time-to-time. While Aphanius are certainly not as colourful as some of their relatives their interesting behaviour and continuous activity make them fascinating aquarium subjects and well worth a try if you possess the dedication to take on a long-term maintenance project since conservation is key with all members of the genus.
It currently contains 22 species and subspecies which are thought to have derived from a common ancestor originally distributed around the periphery of the former Tethys Sea. None are particularly well-documented in aquarium literature although some are very beautiful and the majority are not too difficult to maintain and breed. Sadly most are on the verge of extinction for one reason or another with several existing only in remnant, highly-localised populations.
In practically all cases the root cause for this decline is the activity of humans and although some species are now protected by conservation law the mismanagement and degradation of their habitats continues at an alarming rate. A few species are still sometimes listed as members of Lebias although that name has long been considered a synonym of Cyprinodon by most authorities and an ICZN committee voted to suppress the name in favour of Aphanius as recently as 2003.
References
- Campo, J.P. 2008 - www.soesic.org
Salida de Observación y Colecta, Turquía - Hrbek, T. and A. Meyer. 2003 - J. Evol. Biol. 16(1): 17-36.
Closing of the Tethys Sea and the phylogeny of Eurasian killifishes (Cyprinodontiformes: Cyprinodontidae). - Leonardos, I. 2008 - Sci. Mar. 72(2): 393-401.
The feeding ecology of Aphanius fasciatus (Valenciennes, 1821) in the lagoonal system of Messolongi (western Greece). - Wildekamp, R.H., F. Küçük, M. Ünlüsayin, and W. V. Neer. 1999 - Turk. J. Zool. 23: 23-44.
Species and Subspecies of the Genus Aphanius Nardo 1897 (Pisces: Cyprinodontidae) in Turkey.
