Current status and length–weight relation of the European mudminnow, Umbra krameri (Actinopterygii: Esociformes: Umbridae), from Jieț River, Dolj County, southwestern Romania

Abstract

The habitat of the European mudminnow, Umbra krameri Walbaum, 1792, is continuously decreasing due to human intervention. The species has a “vulnerable” status according to the IUCN Red List. Thus, new information about the species is needed for conservation efforts. Minnow traps were used for capturing Umbra krameri and other small fishes in the Jieț River, Dolj County, southwestern Romania. Captured specimens of U. krameri were measured and weighed. Length–weight relations and relative condition factor were determined for the captured U. krameri specimens. A total of 94 fishes were captured using the minnow traps. They represented 7 species: European bitterling, Rhodeus amarus (Bloch, 1782), roach, Rutilus rutilus (Linnaeus, 1758), rudd, Scardinius erythrophthalmus (Linnaeus, 1758), Danubian spined loach, Cobitis elongatoides Băcescu et Mayer, 1969, weatherfish, Misgurnus fossilis (Linnaeus, 1758), tubenose goby, Proterorhinus marmoratus (Pallas, 1814), and U. krameri. The specimens of Umbra krameri represented 44% (41 specimens) of the total catch. The wet body weight (BW) of U. krameri ranged from 0.8 to 5.1 g, having a mean value of 2.102 g. The mean total length (TL) was 5.782 cm, ranging from 4.59 to 7.87 cm. According to the length–weight relation (LWR), the growth type of U. krameri was positive allometric based on the determined equation: BW = 0.0068TL3.277. The mean value determined for the relative condition factor (Kn) was 1.0056486. The growth condition of 46% of the specimens was poor (Kn < 1; n = 19), while the other 54% were in good condition (Kn ≥ 1; n = 22). The presently reported study provides information about the presence of U. krameri in the Jieț River (Dolj County, Romania), a location where the species has not been previously reported. The LWRs show an allometric positive growth. The relative condition factor shows that 46% of the specimens had poor growth, while the rest were in good condition. Minnow traps were an efficient tool for small fish capture.