The ide or orfe looks rather like a cross between a chub and a roach, with perhaps a bit of dace thrown in for good measure. It has a curved blue-green back, silver sides and a white belly. The golden variety is specially bred for its colour which ranges from pale yellow to a deep reddish orange.
The mouth is small and slightly upturned — ideal for surface feeding. The ide’s tail and dorsal fins are grey; the others are pink and (unlike the chub’s) concave. The dorsal fin starts behind the pelvic fin base. The surest method of identification is to count the scales along the lateral line; ide have 55-61, roach and chub 42-46.
Breeding and feeding
In April or May ide form into large shoals and migrate upstream to faster, shallow water with a sand or gravel bottom. Here spawning takes place with a great deal of leaping and splashing. The sticky eggs are laid on stones and weed, after which the ide return downstream in dense shoals.
After 15 to 20 days the eggs hatch, and the young ide move to calmer water. At first they feed on planktonic animals, but as they grow older they start to eat insects, crustaceans and molluscs – larger specimens also eat small fish.
The ornamental orfe has a similar lifestyle, but as it is mostly found in still waters it can only migrate to the shallow weedy margins for spawning. Those golden orfe that escape from domestic ponds and back into running water quickly revert to upstream migration for breeding.
Both varieties of ide/orfe reach sexual maturity at around five years old, by which time they are 30-40cm (12-16in) long, and weigh l1/2-21/2lb (0.7-1.2kg). Like the roach, the ide lives for about 12-15 years – a big specimen could reach 20 years or more and weigh up to 10 lb (4.5kg).
Finding the ide and orfe
The ide is widespread in northern Europe from the Rhine eastwards into Asia. It’s not found in southern Europe or northern Scandinavia, but has been introduced to a few waters in France, Holland, Denmark and Britain – notably the River Annan in The Borders and the Kennet in the south.
The golden orfe has been quite widely stocked in British lakes and ponds where it is popular as an ornamental fish — a lot of ‘goldfish’ are really orfe. Because it is primarily a surface feeder it doesn’t make the water as muddy as goldfish or carp.
Ide are found in still waters and the lower reaches of rivers (the bream zone), sometimes even the brackish water where the river meets the sea. They prefer weedy areas of moderate depth such as the edges of reed-beds.
This little-known fish has one of the most limited ranges known to any species. It is confined mainly to the basin of the Akheloos River on the mainland of Greece.
The Akheloos rises in the Notia Pindos mountain region and twists its way through arid land before it flattens off near the coast and enters the Ionian Sea opposite the island of Kefallinia.
The fish appears to be resident only in the lower part of the river which is, in any case, not particularly large; its numbers are therefore somewhat restricted.
The Aristotle’s catfish is much like the common European catfish or wels. It has the typical small dorsal fin with three to five rays, and a very long anal fin.
Like those of the wels, the Aristotle’s eyes are small and it is either muddy brown or dark grey. Its sensitive barbels indicate that it is a bottom-dweller, hunting more by touch than sight. The only significant difference between the two is in the number of barbels. The Aristotle’s has two long barbels on its upper jaw and a shorter pair under the chin. Its British counterpart also has two long barbels, but four (not two) short ones.
The Aristotle’s weighs less than the wels. Indeed, 300-335 lb (136-151kg) seems to be its limit, while the wels can reach as much as 700 lb (318kg) in weight.
However, this could simply be a reflection of the limitations of the river itself- and its scanty food supplies – rather than any incapacity on the part of the fish to grow larger.
Warm water spawner
The Aristotle’s spawns in July and August when the water begins to warm up after what can be quite a cold winter in that region.
The female lays her eggs in the typical catfish nest – in hollows under overhanging banks or among tree roots. They are then fertilized by the male who mounts guard on the nest and on the newly hatched fry. At birth they resemble tadpoles but their growth is swift and soon they are eating small crustaceans and worms in preparation for moving on to a fish diet.
The Aristotle’s food is like that of the wels: mainly fish, such as small carp, but also water birds and reptiles.
Various species of catfish are very important economically all over eastern and southern Europe and right down through the Balkans. In Greece fresh water netting is a major village industry and an Aristotle’s is a prize catch.
The fish’s flesh is highly valued and of course its great bulk – a maximum length of 5ft (1.5m) – makes it much sought after. However, recent estimates indicate that the pressure on the Akheloos River is now at such a high level that the future of the Aristotle’s catfish – already a very rare fish -must be in some doubt.