New morphological data on the first-stage larvae of two Procamallanus species (Nematoda: Camallanidae) based on SEM studies

First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopyV článku jsou popsána první stádia larev of kamlanidních hlístic Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) a Procamallanus (Procamallanus) sp. z přirozeně infokovaných ryb Distichodus niloticus (Hasselquist) a Clarias gariepinus (Burchell), z jezera Turkana v Keni (nová lokalita).First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscop

Phases of the ontogenesis of the Mušov Reservoir of the waterwork Nové Mlýny - fish yield and condition parameters of silver bream (Blicca bjoerkna)

Overall yields of the carp and of the non-preferred group of coarse "other fish" exhibited in the Mušovská nádrž Reservoir (Fishing ground MRS Dyje 7) significant changes during 1981-2001. The decrease of yield during 1996-1999 is significantly correlated with a decreased fishing pressure (number of fishing visits per year and hectare of fishing ground) while it insignificantly correlates with the quantity of annually stocked carps. The length/weight relationship of the silver bream, if comparing the values from 1980 with those from 1996, exhibit a significant drop. It was concluded, that the reservoir is actually in a phase of stabilised production and characteristic by a feeding competition between the carp as a preffered game fish and the coarse fishes. Also an increased predation by wells exhibited on the non-predatory fishes including the stocked carp can not be excluded

Heavy metals in parasite-host systems: tapeworm vs. fish

Concentrations of heavy metals in two parasite-host systems (tapeworm vs. fish) were analysed. In the system Ligula intestinalis vs. common bream Abramis brama, white bream Blicca bjoerkna and roach Rutilus rutilus were found in the biomass of plerocercoids mean heavy metal concentrations ranging in Pb 3.20-4.51, in Cd 0.21-0.31, in Cr 1.13-3.16 mg/kg in the 100% dry matter. Regarding the values of accumulation ratio, the parasite accumulated 12.5-18.9 time more Pb, 2.3-3.0 times more Cd, and 4.4-14.1 times more Cr, compared to heavy metal concentrations in the muscles of intermediate hosts

Past and present of the "Angling Paradise" (fishing-ground of the Moravian Anglers Union, Dyje 7)

The comparison of fishery catches in the fishing-ground MRS Dyje 7 during the riverine (1953-1978) and lake (1981-2003) periods shows differences in species composition and quantity. Due to impoundment and fishery management (stocking), carp, bream, perch, pikeperch, asp and wels increased their production considerably. The area studied belongs presently to the most productive MRS fishing-grounds with a mean annual yield of almost 50 tones fish (95,8 kg.ha-1)

Genus Cyprinus Linnaeus, 1758 - actual review on species diversity

In the genus carp (Cyprinus) is included currently 22 taxons in species levels and his fission into two subgenus: Cyprinus s. str. (with 17 species) and Mesocyprinus (with 5 species). Typical taxon on first subgenus Cyprinus (C.) carpio evaluate as a polytypical (with 4 subspecies). From 17 species of subgenus Cyprinus are 8 endemics only in Chinese province Yunnan (=Jünan), 1 species (C. qionghaiensis) province Sechwan, 1 species (C. acutidorsalis) on island Hainan, 5 species in northern as far as middle Vietnam and 1 species (C. intha) in Burma. Geographical distribution of 4 subspecies (C. carpio) is conformable with former views (Kirpichnikov 1967) and number of 2 - 3 domestication centres (Baruš et al. 2002). In subgenus Mesocyprinus registered species are Chinese faunistic elements with C. multitaeniata, that the was ascertained also in northern Vietnam