Preliminary telemetry data on the movement patterns and habitat use of European catfish (Silurus glanis) in a reservoir of the River Ebro, Spain

Abstract –  Knowledge of the movements and diel behaviour of the European catfish ( Silurus glanis ), the largest European freshwater fish, is limited to anecdotal information. In a preliminary telemetry study of European catfish, the spring diel movement patterns of five adult catfish were examined. After intraperitoneal insertion of the acoustic tags, the positions of the fish were recorded automatically in the Flix Reservoir (River Ebro, NE Spain). A marked nocturnal mobility pattern was observed throughout the study. During daytime, the catfish were consistently located in the littoral zone and spent extended periods of the day hidden in concealed habitats. Catfish movements were in a radial pattern, with upstream and downstream excursions followed by returns to a previously occupied location. Significant individual variations in movement pattern were observed among the tagged fish and within the 24 h cycle for each fish. Mean instantaneous swimming speed was 0.17 body lengths per second (BL·s⁻¹) at night but 0.09 BL·s⁻¹ during the daytime.     

Do early infant feeding practices vary by maternal ethnic group?

OBJECTIVE: To examine UK country and ethnic variations in infant feeding practices. DESIGN: Cohort study. SETTING: Infants enrolled in the Millennium Cohort Study, born between September 2000 and January 2002. SUBJECTS: A total of 18 150 natural mothers (11 286 (8207 white) living in England) of singleton infants. OUTCOME MEASURES: Breast-feeding initiation, breast-feeding discontinuation and introduction of solid foods before 4 months. EXPLANATORY VARIABLES: Maternal ethnic group, education and social class. RESULTS: Seventy per cent of UK mothers started to breast-feed, of whom 62% stopped before 4 months. Median age at discontinuing breast-feeding was 14, 13, 10 and 6 weeks in Scotland, England, Wales and Northern Ireland, respectively. Thirty-six per cent of UK mothers (34% in England) introduced solids before 4 months. White mothers were more likely to discontinue breast-feeding (62%) and introduce solids early (37%) than most other ethnic minority groups; those stopping before 4 months were more likely to introduce solids early compared with those continuing to breast-feed beyond this age (adjusted rate ratio (95% confidence interval): 1.3 (1.1-1.2)). Educated mothers were less likely to stop breast-feeding before 4 months (white mothers, 0.8 (0.8-0.9); non-white mothers, 0.9 (0.8-1.0)) than those with no/minimal qualifications but, among ethnic minorities, were more likely to introduce solids early (1.3 (1.0-1.6)). Socio-economic status was positively associated with breast-feeding continuation among white women, and with age at introduction of solids among non-white women. CONCLUSIONS: We have identified important geographic, ethnic and social inequalities in breast-feeding continuation and introduction of solids within the UK, many of which have not been reported previously. The factors mediating these associations are complex and merit further study to ensure that interventions proposed to promote maternal adherence to current infant feeding recommendations are appropriate and effective.     

Agricultural expansion: land use shell game in the U.S. Northern Plains

Land area planted to row crops has expanded globally with increased demand for food and biofuels. Agricultural expansion in the Dakota Prairie Pothole Region (DPPR), USA affects a variety of agricultural and non-agricultural land-use types, including grasslands and wetlands that provide critical wildlife habitat and other ecosystem services. The purpose of this study was to quantify recent changes in rural land cover/land use, analyze trends, and interpret results in relation to climate, agronomic practice, and ethanol production. The primary data sources were 1980–2012 statewide cropland data from the U.S. Department of Agriculture (USDA) National Agricultural Statistics Service, and the USDA Cropland Data Layer, produced annually for the DPPR from 2006 through 2012. Area planted to corn or soybean row crops increased, and small grain (e.g., wheat, barley) area decreased significantly over the analysis period. Corn and soybean expanded by 27 % in the DPPR between 2010 and 2012 alone, an areal increase (+15,400 km²) larger than the U.S. state of Connecticut. This expansion displaced primarily small grains and grassland (e.g., pastures, haylands, remnant prairies). Grassland regularly exchanged land with corn and soybean, small grains, and wetlands and water. Corn and soybean had high inter-annual self-replacement values (68–80 %), and continuous corn/soy row cropping was the second most common combination over a three-year period, ranking after continuous grassland. Small grain self-replacement values were only 22–35 %, indicating frequent relocation in the landscape. Temporary gains in wetland and grassland area were attributed to unusually wet climatic conditions and late snowfalls that prevented crop planting. Nearly all of the region’s ethanol refineries were located where corn and soybean crops constituted 50 % or more of the land area. Quantification of grassland losses in the U.S. Northern Plains requires evaluation of all land uses that interact with grasslands, and a longer term perspective that incorporates grassland as part of a normal land-use rotation.     

Escherichia coli challenge and one type of smectite alter intestinal barrier of pigs

An experiment was conducted to determine how an E. coil challenge and dietary clays affect the intestinal barrier of pigs. Two groups of 32 pigs （initial BW： 6.9 ± 1.0 kg） were distributed in a 2 x 4 factorial arrangement of a randomized complete block design （2 challenge treatments： sham or E. coil, and 4 dietary treatments： control, 0.3% smectite A, 0.3% smectite B and 0.3% zeolite）, with 8 replicates total. Diarrhea score, growth performance, goblet cell size and number, bacterial translocation from intestinal lumen to lymph nodes, intestinal morphology, and relative amounts of sulfo and sialo mucins were measured. The E. coli challenge reduced performance, increased goblet cell size and number in the ileum, increased bacterial translocation from the intestinal lumen to the lymph nodes, and increased ileal crypt depth. One of the clays （smectite A） tended to increase goblet cell size in ileum, which may indicate enhanced protection. In conclusion, E. coli infection degrades intestinal barrier integrity but smectite A may enhance it.     

Utilization of dietary starch and glucose tolerance in juvenile chinook salmon (Oncorhynchus tshawytscha) of different strains in seawater

Juvenile chinook salmon of three strains responded to inclusion of 28.7% of gelatinized starch in the diet with different degrees of reduction in growth rate and feed efficiency relative to control fish of the respective strains fed a low-starch, high-lipid diet of similar protein (46%) and estimated metabolizable energy content (16 mJ/kg). The productive protein value of the diet was not reduced to the same extent by the high intake of starch. Carcasses of fish fed the high-starch diet contained higher concentrations of protein and lower concentrations of lipid than control fish. The accumulation of liver glycogen in response to the high-starch diet differed among strains. Glucose tolerance curves also varied among strains but were poorly correlated with plasma concentrations of insulin. Tolerance to glucose loading was improved in fish previously fed the high-starch diet.     

Lysine uptake by mammary gland tissue from lactating sows

Kinetic properties and substrate specificity of the lysine transport system in porcine mammary gland were studied using mammary tissue explants from nine lactating sows. Sodium dependence of lysine uptake was determined by replacing sodium in the medium with choline. Kinetic parameters of lysine uptake were determined using lysine concentrations from 5 microM to 5.12 mM. Competition of lysine uptake by other amino acids was determined using the cationic amino acids, arginine and ornithine, and using other essential amino acids. Transport of lysine was time-dependent and was unaffected by replacing sodium with choline. Lysine uptake occurred by a transport mechanism with a Km of approximately 1.4 mM and a Vmax of 7.9 mmol x kg cell water(-1) x 30 min(-1). Lysine uptake was inhibited by arginine and ornithine and by high concentrations of L-alanine, L-methionine, L-leucine, cycloleucine, and D-lysine, but not by 2-(methylamino)-isobutyric acid. This transport mechanism is the primary system responsible for uptake of cationic amino acids in lactating sow mammary tissue. The relatively high Km, compared with physiological blood concentrations of lysine, indicates that the kinetic properties of the lysine transport system should not be limiting to milk protein synthesis. Transmembrane transport of lysine by lactating sow mammary tissue should be a direct function of plasma concentrations. However, interactions of other amino acids with the uptake system may affect lysine uptake.     

Iron storage disease in captive Egyptian fruit bats (Rousettus aegyptiacus): relationship of blood iron parameters to hepatic iron concentrations and hepatic histopathology.

This study evaluated the relationship between blood iron parameters and hepatic iron concentrations, and correlation of histologic findings with hepatic iron concentrations in a captive population of Egyptian fruit bats (Rousettus aegyptiacus) and island flying foxes (Pteropus hypomelanus). Blood samples were collected for complete blood counts, plasma biochemical profiles, serum iron concentrations, total iron-binding capacity, whole-blood lead concentrations, and plasma ferritin assays. Liver samples obtained by laparotomy were divided, with one half processed for histologic examination and the other half frozen and submitted for tissue mineral analysis. The histologic sections were scored by two blinded observers for iron deposition, necrosis, and fibrosis. The Egyptian fruit bats had significantly higher liver iron (mean = 3,669 +/- 1,823 ppm) and lead (mean = 8.9 +/- 5.8 ppm) concentrations than the island flying foxes (mean [Fe] = 174 +/- 173 ppm, mean [Pb] = 1.9 +/- 0.5 ppm). Hepatic iron concentrations significantly correlated with tissue lead concentrations, histologic grading for iron and necrosis, serum iron, transferrin saturation, and plasma ferritin (P < 0.001). Blood lead concentrations negatively correlated with tissue lead concentrations (P < 0.001). When the product of transferrin saturation and serum iron was greater than 51, an individual animal had a high probability of having iron overload. When the product of these two variables was greater than 90, there was a high probability that the animal had hemochromatosis. On the basis of this study, it appears that evaluation of serum iron, transferrin saturation, and plasma ferritin are useful and noninvasive methods for diagnosis of hemochromatosis in Egyptian fruit bats.     

Fungal diseases of rabbits.

Although fungal diseases in rabbits are reported, they are encountered infrequently in clinical practice. The most common fungal disease is a superficial dermatophytosis, with deep mycotic infections being rare. Rabbits can be asymptomatic carriers of dermatophytes and should be considered a potential source of zoonotic exposure. Treatment protocols often are based on common small animal regimes. Rabbits also have normal gastrointestinal yeast that often is found on routine fecal examinations.     

Contents Volume 132 2003

Volume Contents

Contents Volume 132 2003