Aetiology of an ulcerative disease in goldfish, Carassius auratus (L.): characterization of the causative agent

Abstract. A bacterium resembling Aeromonas salmonicida and determined to be the aetiologic agent of a cutaneous ulcerative disease in goldfish Carassius auratus (L.) was further characterized in this study.
Forty-five isolates of the bacterium (43 from the United States and one each position (moles % guanine plus cytosine) and DNA homology. The bacteriological atypical A. salmonicida previously described. Several important biochemical characteristics distinguished the goldfish isolates from typical A. salmanicida , but the DNA binding experiments indicated a high degree of relatedness between the goldfish isolates and typical A. salmonicida strains.     

Comparative studies of PKX and Sphaerospora spp. from salmonids using lectin and monoclonal antibody staining techniques

The results of comparative immunohisto-chemical staining studies with two lectin probes, GS-I and SBA, and five monoclonal antibodies raised against the PKX myxosporean are presented. In order to investigate the postulated link between PKX and Sphaerospora spp., the lectins and monoclonal antibodies were tested against PKX, Sphaerospora renicola, Sphaerospora oncorhynchi, Sphaerospora elegam, Sphaerospora truttae and Sphaero-spora sp. from Atlantic salmon, Salmo salar L., and Ceratomyxa shasta. SBA appears a useful tool for tbe diagnosis of all Sphaerospora spp. infections and was also positive for C. shasta. GS-I and monoclonal antibodies (12, C5, D4 and A3) appear to be specific for both the extrasporogonic and sporogonic stages of PKX. Although MabB4 was raised to PKX, it appears to stain some of the sporogonic stages of Sphaerospora spp. but not C. shasta. The results of the lectin and monoclonal staining of PKX and Sphaerospora oncorhynchi indicated that further work was required to prove or disprove the hypothesis that PKX and S, oncorhynchi are the same organism.     

Single and composite influence of growth-related candidate gene polymorphisms on additive genetic variation of birth weight in charolais beef cattle

The objective of the present experiment work was to evaluate the effect of the inclusion of genomic information on the additive genetic variance of birth weight (BW) of Charolais cattle in Mexico. Variance components and heritability were estimated using four linear models. The first model was the base model (BM) from which single and composite effects of selected single-nucleotide polymorphism (SNP) markers were evaluated (BM1, BM2, and a composite BM3). Genetic markers were included in a regression model and analyzed by stepwise regression against adjusted BW from a panel of growth-related traits candidate gene markers. After two regression rounds, two SNPs (R ²?>?0.02) were chosen to include into the animal models as fixed effects. Growth hormone receptor gene GHR 4.2 and GHR 6.1 SNPs were selected from a panel of 39 SNPs. GHR 4.2 had a negligible effect on BW, whilst GHR6.1, interestingly, explained ～9 % of genetic variance (p?=?0.0877) with an α_G>A?=?0.509. The inclusion of markers in M2 and M3 reduced 19 and 15 % of the additive genetic variance, respectively. Both adjusted significantly better the linear model (LRT?=?p?<?0.01). Results obtained suggest that the previous selection of markers in a candidate gene approach and subsequent inclusion of selected SNPs into animal model might provide a better fit, avoiding the overestimation of genetic variance components and breeding values for BW.     

Larval lobster (Homarus americanus) distribution and drift in the vicinity of the Gulf of Maine offshore banks and their probable origins

Surveys for lobster larvae in offshore waters of the north‐eastern Gulf of Maine in 1983, 1987 and 1989 confirm that local hatching occurs mainly at depths <100 m over the banks, including Georges and Browns Banks. Detailed studies in the vicinity of Georges Bank in late July of both 1987 and 1989 indicate that the first and second moult stages were located primarily over the bank whereas stages III and IV lobster were collected both over and off the bank. At times stage IV lobster were more abundant off the bank than over it. The condition of stage III and IV lobster, as measured by a lipid index, was better off than over Georges Bank in 1988 and 1989 indicating a possible physiological advantage to being off the bank. In addition, the higher surface temperatures off Georges Bank would shorten larval development time to settlement. To determine the probable hatch sites of stage IV lobster collected off of Browns Bank in 1983 and off of Georges in 1987 and 1989, a 3‐D circulation model of the Gulf of Maine was used to simulate larval lobster drift backwards in time. In all cases, areas off Cape Cod, MA, and off Penobscot Bay, ME were suggested as the source of the larvae, although most of the larval trajectories never reached these near‐shore waters that are well‐known, larval hatching areas. The model‐projected larval release times match most closely the observed inshore hatch off Massachusetts but model uncertainties mean that coastal Maine cannot be ruled out as a source. Georges Bank is also a potential source because the present model does not take into account short‐term wind events, off‐bank eddy transport or the possibility of directed off‐bank larval swimming. Examination of weather records prior to and during our 1988 and 1989 sampling periods indicates that winds were not of sufficient intensity and duration to induce larval transport off Georges Bank. The shedding of eddies from the northern flank of Georges Bank into the Gulf of Maine are a relatively common phenomenon during summer but not enough is known about them to evaluate their contribution to possible cross‐bank transport of lobster larvae. Directed larval swimming is another possible source for the stage IV lobster found near Georges Bank. Plankton distributions across the northern frontal zone of Georges Bank in 1988 were used as proxies for the scarce larval lobsters. The more surface distribution of the microplankton, in particular, supports the possibility that wind and eddy events may be important in the transport of stage III and IV lobsters off of Georges Bank. Further studies are needed to evaluate these possible additional sources of advanced stage lobster larvae found off of the offshore banks.     

Variable impacts of reduced and zero tillage on soil carbon storage across 4–10 years of UK field experiments

Journal of Soils and Sediments - Reduced tillage has been advocated as a practical measure to increase soil carbon in long-term cropping soils. We examine three medium-term experiments in sites...     

Rib osteomyelitis in three foals

Three foals aged between 21 and 44 days were presented for evaluation of pyrexia and lameness. Each had subcutaneous abscessation associated with osteomyelitis of a rib at the costochondral junction and pathological fracture of the affected rib; one foal had more than one rib affected. Other localised sites of infection included other sites of osteomyelitis, omphalophlebitis, uveitis, enterocolitis, and calcaneal bursitis. The subcutaneous abscessation and rib osteomyelitis was treated surgically in two foals. Salmonella typhimurium was isolated from the subcutaneous abscess in one foal and from the faeces of another. Two of the three foals were euthanased. Ultrasonography was a more useful modality than radiography for establishing the diagnosis of costal osteomyelitis.     

Changes in the third metacarpal bone and frequency of bone injuries in young quarter horses during race training - observations and theoretical considerations

Fifty-three Quarter Horses were put into race-training at 18 mo of age. Changes in the third metacarpal were monitored by radiographic densitometry initially at 83 days prior to the commencement of training and at days 0, 62, 104 and 244 of training. A normal increase in density of the third metacarpal due to growth and mineralization was seen from the first set of radiographs until the horses began training at day 0 (P<.001). Bone density then decreased to day 62 (P<.001), remained low through day 104 before it began to increase to day 244 (P<.005). Differences in the most optically dense portion of each cortex of the third metacarpal were compared in horses completing the study without injury and those sustaining a bone-related injury. Horses experienced fewer injuries when they had greater cortical mass in the lateral (P<.05) and medial (P<.1) aspects of the third metacarpal, relative to the palmar aspect, at the commencement of training.