Foreign brown trout in protected landscapes as a consequence of connectivity

Abstract To preserve the local genetic patrimony of wild aquatic species, population enhancement should be limited to supportive breeding of native lineages and controlled releases in target areas with depleted population size. This is the case of brown trout, Salmo trutta L., in northern Iberia, a species of high economic and cultural value in the region. Employing a combination of conserved and hypervariable genetic markers, illegal stocking of domestic brown trout in protected areas (National Park, Natural Reserve) within the Cantabric chain was detected. The most likely origin of the domestic individuals was determined by assignment tests to hatchery stocks as a result of past releases conducted downstream and out of the protected areas. Where connectivity exists along a water course, the entire drainage should be considered as a single management unit to preserve the native genetic diversity of upstream protected areas.     

Myopathies in a riding horse stable

In this case report on myopathies in 6 saddle-horses, a combined dietary vitamin E and selenium deficiency is presumed. Other disorders, such as exertional myopathy ("Monday morning disease") due to excessive energy intake or ionophore intoxication could be excluded by calculating the energy supply or by a simple colour test. The selenium requirement of horses is estimated to 0.1-0.2 mg/kg dry matter (Meyer 1986). If natural feed compounds are low in selenium, adequate amounts of this trace element can be supplied by means of supplemental feeds, sodium selenite (20 mg/500 kg BW/week) or bruised linseed (cooked, 200-500 g/d). In horses tolerance of increased selenium intake is low. After oral administration of sodium selenite lethal dose was 3.3 mg/kg bodyweight. In feedstuffs selenium concentration must be below 5 mg/kg dry matter (Traub-Dargatz et al, 1986). The intake of vitamin E should be 0.25-1 mg/kg bodyweight. The requirements are influenced by feed compounds, especially the concentration of dietary unsaturated fatty acids, and the performance of the horses (Meyer 1986). Foals, pregnant or lactating mares, and racing horses have higher requirements. In acute disease vitamin E and selenium are given parenterally (5 mg Se/horse) or by oral application of sodium selenite (46% selenium, 20 mg/horse), in addition to symptomatical treatment.     

High prevalence of betanodavirus barfin flounder nervous necrosis virus as well as red‐spotted grouper nervous necrosis virus genotype in shellfish

Using two serially executed PCRs, the discriminative multiplex two‐step RT‐PCR (DMT‐2 RT‐PCR) following the detection seminested two‐step RT‐PCR (DSN‐2 RT‐PCR), we found a high frequency presence of BFNNV genotype as well as RGNNV in various domestic and imported shellfish. This was definitely different from the previous reports of outbreaks and asymptomatic infection only by the RGNNV genotype in cultured finfish in Korea. Cultivation of NNV entrapped in shellfish was performed successfully by a blind passage. Thus, in an attempt to elucidate the epidemiology of betanodavirus, experiments conducted on 969 shellfish samples concluded that (i) distribution of NNV genotype, especially BFNNV, in shellfish is clearly different from that found in finfish of the world; (ii) unlike RGNNV, which showed a high rate in summer, BFNNV showed no seasonal variation and this result suggests BFNNVs in the marine environment remain fairly constant throughout the year; and (iii) the entrapped virus in shellfish was alive and culturable in vitro. These results are the first report of high level prevalence of in vitro culturable NNV in shellfish, for both BFNNV and RGNNV, which may present a potential risk in transmitting nodaviruses to host species in a marine environment.     

Shining a light on the loss of rheophilic fish habitat in lowland rivers as a forgotten consequence of barriers,and its implications for management

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Diagnosis of liver diseases in the horse

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