Umbra
Fam. Umbridae and Gen. umbra
Umbras are small fishes that live in slow-flow and stagnant waters of Euro-Asia and North America . They are mostly bound to a muddy bottom. They are characterized by a far back placed fin, not clearly visible little hump and a round chest fin near the throat. They spawn in spring. The Umbridae family has got three genera and five species, the two of which live in Europe – autochthonous Umbra krameri and introduced Umbra pygmaea. In Serbia there is only Umbra krameri.
The teeth are placed on both the palatal bones and the vomer in several rows. Besides the European species this genus also includes Umbra limi and Umbra pygmaea. The species of Umbra limi (Kirtland,1841) and Umbra pygmaea (Dy Kay,1842) are spread in the central and eastern parts of North America.
Biological Characteristics of the Species
The head is big. The side part of it and the grill lids are covered with scales. The eyes are big, placed closer to the top of the head. It can grow up to 13-15cm (the males are smaller) and the weight is not more than 30gr. The scales are big with no apparent centre or radial canals. The body is red-brown. Scattered dark spots can be seen on the head and on the sides. Along the upper part of the body there is a light-yellow stripe. The mouth is rather small and the proboscis is short. The teeth are not well developed. It has the ability to use the atmospheric oxygen so that it can stand without water over 10 hours. It lives in smaller schools, 5-6 fishes. It can float a few hours without moving under the angle of 60-70° with the head directed to the bottom waiting for the prey to come closer.
Feeding and Breeding
It eats insect larva, crabs, mollusks and sometimes fish. It attacks its prey from ambush, similar to pike.
It becomes sexually mature after two years, at length of 6-8cm. It spawns in spring during the night or at dawn, at the temperature of 12-18°C in the parts with thick vegetation. The female lays 75-2700 eggs at the bottom which she carefully takes care of. This lasts for 4-5 days .
Biotope and Living Area
They live in swampy waters with thick vegetation and at muddy bottoms. Bentopelagium with characteristics of water: pH 6,0-6,5; dH 5,0; t aq=5-24°C is very suitable for it. Being endangered by drought it digs itself into mud.
Nizider lake, downstream of the Dnepr, the part of Hungary , The Czech Republic and Slovakia). There are some data about the presence of Umbra in Croatia , in the Mura river. In Serbia it used to live in the mouth of the Danube, in the valley of the Mlava, the Pek and down the Tisa river. The first to give information about the presence of umbra in Serbia was Josif Pančić (1860) and the second was Medić (1896) in the flooded part of the Sava river, near Surčin. Today it can only be found in the water current of the Zasavica which was proclaimed to be the Special Nature Reserve in 1997.
Species Protection
In the whole of Europe umbra has the status of endangered species and is under the strict regime of protection (EN). It is on the list of protected species given by the Berne Convention Appendix I-Annex I. In the area of Serbia Umbra krameri is continually protected as natural rarity of Serbia according to the Regulation of Protection of Natural Rarities (Official Gazette of the Republic of Serbia number 50 from 09.07.1993.).
