Water parameters affect anaesthesia induced by eugenol in silver catfish,Rhamdia quelen

The present study investigated the effects of water pH (5.0, 7.0 and 9.0), hardness (0, 20 and 120 mg CaCO₃ L^?1) and temperature (15, 23 and 30 °C) on the induction of sedation and anaesthesia, and subsequent recovery, of silver catfish exposed to eugenol. Moreover, the blood gas tensions (PvO₂ and PvCO₂) and blood pH in silver catfish acclimated to these temperatures were investigated after exposure to eugenol. Water pH, hardness, temperature and fish size affect the efficacy of eugenol in silver catfish, particularly at the lower concentrations tested (20 and 30 mg L^?1). Sedation of this species can be induced at concentrations as low as 20 mg L^?1, but for anaesthesia, a concentration of at least 40 mg L^?1 of eugenol must be used to compensate for the influence of fish size and water quality. Blood gas tension and pH were affected by eugenol anaesthesia, but only in fish acclimated to 30 °C.     

Rapid salinity changes affect the survival and physiology of a penaeid prawn: Implications of flood events on recruitment to the fishery

Estuaries act as nurseries for many penaeid prawns, but these habitats are highly susceptible to salinity decline through flooding. The rate of salinity decline and duration of exposure to non‐optimal salinity may affect survival and subsequent recruitment of prawns to the fishery. This study aimed to determine the effect of salinity fluctuations observed in local estuaries during flood events using a novel dilution approach. Mortality of juvenile Melicertus plebejus (Hess) was assessed after 24 hr exposure to 24 rates of salinity decline ranging from 0.01% to 20% per hr. After the salinity decline, prawns were held at the final salinities for five days before again assessing mortality as well as aerobic metabolic rate and prawn water content. Salinity decline from 36 to ~0.8 led to 50% mortality, but continued exposure to low salinity for five days increased mortality at this salinity to 99% and shifted the 50% mortality point to salinity ~5. Aerobic metabolic rate and water content data suggested the cause of mortality due to exposure to salinities < 5 was osmoregulatory failure. Rapid salinity declines over 24 hr and sustained low salinity due to flooding could compromise the survival of juvenile prawns, potentially reducing recruitment to the fishery.     

Immune Status and Hepatic Antioxidant Capacity of Gilthead Seabream Sparus aurata Juveniles Fed Yeast and Microalga Derived β-glucans

This work aimed to evaluate the effects of dietary supplementation with β-glucans extracted from yeast (Saccharomyces cerevisiae) and microalga (Phaeodactylum tricornutum) on gene expression, oxidative stress biomarkers and plasma immune parameters in gilthead seabream (Sparus aurata) juveniles. A practical commercial diet was used as the control (CTRL), and three others based on CTRL were further supplemented with different β-glucan extracts. One was derived from S. cerevisiae (diet MG) and two different extracts of 21% and 37% P. tricornutum-derived β-glucans (defined as Phaeo21 and Phaeo37), to give a final 0.06% β-glucan dietary concentration. Quadruplicate groups of 95 gilthead seabream (initial body weight: 4.1 ± 0.1 g) were fed to satiation three times a day for 8 weeks in a pulse-feeding regimen, with experimental diets intercalated with the CTRL dietary treatment every 2 weeks. After 8 weeks of feeding, all groups showed equal growth performance and no changes were found in plasma innate immune status. Nonetheless, fish groups fed β-glucans supplemented diets showed an improved anti-oxidant status compared to those fed CTRL at both sampling points (i.e., 2 and 8 weeks). The intestinal gene expression analysis highlighted the immunomodulatory role of Phaeo37 diet after 8 weeks, inducing an immune tolerance effect in gilthead seabream intestine, and a general down-regulation of immune-related gene expression. In conclusion, the results suggest that the dietary pulse administration of a P. tricornutum 37% enriched-β-glucans extract might be used as a counter-measure in a context of gut inflammation, due to its immune-tolerant and anti-oxidative effects.     

Iridovirus infections in finfish – critical review with emphasis on ranaviruses

Viruses in three genera of the family Iridoviridae (iridoviruses) affect finfish. Ranaviruses and megalocytiviruses are recently emerged pathogens. Both cause severe systemic disease, occur globally and affect a diversity of hosts. In contrast, lymphocystiviruses cause superficial lesions and rarely cause economic loss. The ranavirus epizootic haematopoietic necrosis virus (EHNV) from Australia was the first iridovirus to cause epizootic mortality in finfish. Like other ranaviruses, it lacks host specificity. A distinct but closely related virus, European catfish virus, occurs in finfish in Europe, while very similar ranaviruses occur in amphibians in Europe, Asia, Australia, North America and South America. These viruses can be distinguished from one another by conserved differences in the sequence of the major capsid protein gene, which informs policies of the World Organisation for Animal Health to minimize transboundary spread of these agents. However, limited epidemiological information and variations in disease expression create difficulties for design of sampling strategies for surveillance. There is still uncertainty surrounding the taxonomy of some putative ranaviruses such as Singapore grouper iridovirus and Santee‐Cooper ranavirus, both of which cause serious disease in fish, and confusion continues with diseases caused by megalocytiviruses. In this review, aspects of the agents and diseases caused by ranaviruses are contrasted with those due to megalocytiviruses to promote accurate diagnosis and characterization of the agents responsible. Ranavirus epizootics in amphibians are also discussed because of possible links with finfish and common anthropogenic mechanisms of spread. The source of the global epizootic of disease caused by systemic iridoviruses in finfish and amphibians is uncertain, but three possibilities are discussed: trade in food fish, trade in ornamental fish, reptiles and amphibians and emergence from unknown reservoir hosts associated with environmental change.     

Dietary inclusion of detoxified <Emphasis Type="Italic">Jatropha curcas</Emphasis> kernel meal: effects on growth performance and metabolic efficiency in common carp, <Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.

Jatropha curcas is a multipurpose and drought-resistant shrub or small tree widespread all over the tropics and subtropics. Its seeds are rich in oil, and the Jatropha kernel meal obtained after oil extraction is rich in protein. However, presence of toxic and antinutritional constituents restricts its use in fish feed. Jatropha kernel meal was detoxified. Common carp, Cyprinus carpio, fingerlings (15; av. body mass 10.9 ± 0.65 g) were randomly distributed in three groups with five replicates. A 6-week feeding experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilisation and energy budget. Fish were fed isonitrogenous diets (38% crude protein): control diet (C _ontrol group) containing fish meal (FM) protein based protein and two other diets replacing 75% FM protein with detoxified Jatropha kernel meal (DJKM, J _atropha group) and soybean meal (SBM, S _oybean group). At the end of the experiment, body mass gain, metabolic growth rate, protein efficiency ratio, protein productive value, energy retention, efficiency of metabolised energy for growth and efficiency of energy retention were determined. These parameters were high and statistically similar for C _ontrol and J _atropha groups and significantly lower (P < 0.05) for S _oybean group. Whereas a reverse trend was observed for energy expenditure per g protein retained in fish body. No significant differences were found in heat released, gross energy uptake, metabolised energy intake, metabolisability, energy expenditure, energy expenditure per g protein fed and apparently unmetabolised energy. Conclusively, common carp–fed plant protein (DJKM and SBM) and FM protein–based diets exhibited equal average metabolic rate.     

Virucidal effects of various agents—including protease—against koi herpesvirus and viral haemorrhagic septicaemia virus

In a search for alternative, environmentally friendly and effective disinfecting agents, a commercially available protease—Neutrase^®—was tested in this work for inactivation of koi herpesvirus (KHV) and of viral haemorrhagic septicaemia virus (VHSV). For comparison, the stability of these viral pathogens in similar configurations at various pH values and concentrations of peracetic acid or quicklime, typically used for disinfection, was tested. Therefore, virus suspensions were incubated with various concentrations of different agents for 24 hr and the titre of the remaining infectious particles was determined by virus titration. Furthermore, the treatment of both viruses, with the agents at concentrations that were previously appointed as effective, was also examined in the presence of solid material (quartz sand). All procedures investigated in this study, including the protease treatment, were able to reduce the titre of KHV and VHSV below the detection limit of the titration. Although further studies are necessary, this is the first report of the application of a protease for the inactivation of the selected fish pathogens, demonstrating the great potential of the latter for disinfection.     

Effect of s-triazine and phenoxyalkanoic acid herbicides on UDP-glucuronosyltransferase in rat liver microsomes

Twelve herbicides, representatives of two chemical groups, substituted phenoxyalkanoic acids and s-triazines, were tested for their inhibitory effect on the glucuronidation of 4-nitrophenol (4-NP), phenolphthalein (PPh) and 4-methylumbelliferone (4-MU) by rat liver microsomes. One millimole MCPA, ametryn and cyanazine significantly decreased PPh UDP-glucuronosyltransferase (UGT) activity, while propazine was found to be a most potent inhibitor of 4-NP glucuronidation. Concentrations of 0.1 mM dichlorprop and cyanazine were still inhibitory against PPh-UGT. The inhibition of 4-MU glucuronidation by the herbicides was low and not specific. As a whole, s-triazine derivatives were more inhibitory than the substituted phenoxyalkanoic acids. Kinetic studies with propazine revealed a non-competitive type of inhibition towards the acceptor substrate 4-NP, with an apparent K_i value of 0.540 mM . With ametryn, an uncompetitive type of inhibition against PPh and a mixed type of inhibition towards UDPGA were found, with apparent K_i values of 0.330 mM and 0.380 mM , respectively. © 1999 Society of Chemical Industry     

Genetic diversity in cultivated yam bean (<Emphasis Type="Italic">Pachyrhizus</Emphasis> spp.) evaluated through multivariate analysis of morphological and agronomic traits

Yam bean [Pachyrhizus DC.] is a legume genus of the subtribe Glycininae with three root crop species [P. erosus (L.) Urban, P. tuberosus (Lam.) Spreng., and P. ahipa (Wedd.) Parodi]. Two of the four cultivar groups found in P. tuberosus were studied: the roots of ‘Ashipa’ cultivars with low root dry matter (DM) content similar to P. erosus and P. ahipa are traditionally consumed raw as fruits, whereas ‘Chuin’ cultivars with high root DM content are cooked and consumed like manioc roots. Interspecific hybrids between yam bean species are generally completely fertile. This study examines the genetic diversity of the three crop species, their potentials for breeding and the identification of useful traits to differentiate among yam bean genotypes and accessions. In total, 34 entries (genotypes and accessions) were grown during 2000?2001 at two locations in Benin, West Africa, and 75 morphological and agronomical traits, encompassing 50 quantitative and 25 qualitative characters were measured. Diversity between entries was analyzed using principal component analysis, cluster analysis, multivariate analysis of variance and discriminant function analysis. Furthermore, phenotypic variation within and among species was investigated. Intra- and interspecific phenotypic diversity was quantified using the Shannon–Weaver diversity index. A character discard was tested by variance component estimations and multiple regression analysis. Quantitative trait variation ranged from 0.81 (for total harvest index) to 49.35% (for no. of storage roots per plant). Interspecific phenotypic variation was higher than intraspecific for quantitative traits in contrast to qualitative characters. Phenotypic variation was higher in overall for quantitative than qualitative traits. In general, intraspecific phenotypic variation ranged from 0.00 to 82.61%, and from 0.00 to 80.03% for quantitative and qualitative traits, respectively. Interspecific phenotypic variation ranged from 0.00 to 95.02%, and 0.00?81.58% for the two trait types, respectively. The Shannon–Weaver diversity index (H′) was in general high and over 0.80 for most of the trait. Diversity within P. tuberosus was higher than within P. erosus and P. ahipa. Across the 50 quantitative and 25 qualitative traits, the Shannon–Weaver diversity index of intra- and interspecific variation was around 0.83 and 0.51, respectively and was lower for qualitative than for quantitative traits. Monomorphism was observed in eight qualitative traits and one quantitative character. The first, second and third principal components explained, respectively, 39.1, 21.3 and 8.3% of the total variation in all traits. Pachyrhizus erosus, P. ahipa, and P. tuberosus (‘Chuin’ and ‘Ashipa’) were clearly separated from each other by these analyses. Multivariate analysis of variance indicates significant differences between Pachyrhizus species for all individual or grouped traits. Discriminant function analysis revealed that the first two discriminant functions were almost significant. Biases due to unbalanced sample size used per species were small. Within each species a similar amount of diversity was observed and was determinable to 70% by only ten traits. We conclude that the cultivated yam bean species represent distinct genepools and each exhibits similarly large amounts of genetic diversity.     

Immunological responses following experimental endobronchial infection of badgers (Meles meles) with different doses of Mycobacterium bovis

The Eurasian badger (Meles meles) is a wildlife reservoir for Mycobacterium bovis infection in Ireland and Great Britain and has been implicated in the transmission of tuberculosis to cattle. Vaccination of badgers is an option that could be used as part of a strategy to control the disease. In this study we used an endobronchial infection procedure to inoculate groups of badgers with three different doses (3x10(3), 2x10(2) and <10 Colony Forming Units (CFUs)) of M. bovis. After 17 weeks the disease status of each animal was determined by post-mortem pathology and culture for M. bovis. Each of the inoculum doses resulted in establishment of infection in the badgers. The cell-mediated immune (CMI) responses were measured by lymphocyte transformation assay (LTA) of peripheral blood mononuclear cells (PBMCs) cultured with bovine tuberculin (PPD-B). In each infected group the CMI responses increased with a kinetic profile corresponding to the delivered dose and the post-mortem pathology. The serological responses were measured by ELISA and a multi-antigen print immunoassay (MAPIA) in order to investigate any changes in the antigenic repertoire associated with different infective doses. In contrast to the CMI responses, the ELISA and MAPIA showed that the recognition of antigens by the badgers was intermittent and not strongly influenced by the dose of M. bovis.     

Assessing the role of federal community assistance programs to develop biomass utilization capacity in the western United States

As forest biomass utilization becomes cost effective to harvest, more areas at risk of catastrophic wildfire can be thinned of dense brush and small diameter trees. In an effort to increase biomass utilization, the USDA Forest Service granted more than $36 million in National Fire Plan-Economic Action Program funds in the western United States during fiscal years 2001 to 2003. Interviews with program coordinators and grant recipients were used to characterize the types of investment strategies used and to assess accomplishments relative to national fuels reduction objectives. Findings include a strong emphasis on grants leveraging other funding sources, coordination of resources to increase utilization capacity, and the need for technical assistance to facilitate project design and implementation. We conclude that community assistance programs may help to create the type of utilization capacity necessary to reduce hazardous fuels, but that sustained progress will depend on synergistic activities on multiple fronts and improved demonstration of program accomplishments.