Effect of Stocking Density on Growth,Survival, and Condition of the Mexican Cichlid Cichlasoma beani

The Mexican cichlid Cichlasoma beani is currently exploited regionally as food and can be commercialized in the aquarium trade. Natural populations of C. beani may already be negatively affected by anthropogenic alteration of the areas in which it is distributed. The aim of the present study was to examine the effect on growth, survival, and condition of C. beani cultured in three stocking densities: three (D3), six (D6), and nine (D9) fish per each 40 L tank. At the end of a 6‐wk trial the fish cultured in D3 were longer, heavier, and grew faster than the rest of the treatments but their survival was the lowest compared to D6 and D9. The mortalities were caused by a strong aggressive behavior in D3.     

Theileria orientalis: a review

Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact.     

Clinical efficacy of diclofenac sodium and flunixin meglumine as adjuncts to antibacterial treatment of respiratory disease of calves

Objective To compare the efficacy of the non-steroidal antiinflammatory drugs, diclofenac sodium and flunixin meglumine as adjuncts to the antibiotic treatment of bovine respiratory disease (BRD). Procedure We randomly allocated 80 Holstein calves with BRD to three groups. All the calves received a dose of 2.5 mg/kg tulathromycin by single subcutaneous injection and two of the groups received, in addition, either 2.5 mg/kg diclofenac sodium as a single intramuscular injection (diclofenac group, n = 30) or 2.2 mg/kg flunixin meglumine as an intravenous injection on the first three consecutive days after tulathromycin administration (flunixin group, n = 30). All calves were given a clinical score prior to initial treatment (day 0) and after treatment (days 1, 2, 3, 7 and 14) by observing appetite, demeanour, rectal temperature, the rate and type of respiration, presence or absence of coughing, and nasal discharge. Results During the first 48 h, improvement of adverse signs of respiratory disease, such as pyrexia and elevated respiratory rate, and of a high clinical index score was significant in the two adjunct groups compared with the calves receiving antibiotic alone. The reduction in pyrexia was greatest in the diclofenac group. There were no statically significant differences between treatment groups with regard to eventual perceived recovery from respiratory disease in 14 days. Conclusion In this trial, a single intramuscular dose of diclofenac sodium was equally effective as three intravenous injections of flunixin meglumine given on consecutive days as adjunctive therapy for BRD.     

Biological control ofBotrytis cinerea in residues and flowers of Rose (Rosa hybrida)

Microbial isolates from living petals, petal residues and leaf residues of rose, and from laboratory collections, were evaluated for control ofBotrytis cinerea in rose. In leaf residues artificially infested withB. cinerea, isolates of the filamentous fungiGliocladium roseum, FR136 (unidentified) andTrichoderma inhamatum reduced sporulation of the pathogen by >90%, other filamentous fungi were 25–90% effective, and those of yeasts and bacteria were <50% effective. In artificially inoculated petal residues, no microbe reduced sporulation ofB. cinerea by >75%, but isolates ofCladosporium oxysporum and four yeasts were 51–75% effective, and three filamentous fungi, eight yeasts andBacillus subtilis isolates were 26–50% effective. Isolates ofT. inhamatum, C. oxysporum andG. roseum performed best againstB. cinerea among isolates evaluated in leaf residues naturally infested with the pathogen and indigenous microorganisms. Totals of ten isolates of filamentous fungi (includingC. oxysporum andC. cladosporioides), two of yeasts and five ofBacillus subtilis completely prevented lesion production byB. cinerea in detached petals, and a further six isolates of filamentous fungi (includingG. roseum) and six yeasts were 90–99% effective. Isolates ofC. oxysporum, C. cladosporioides andB. subtilis, the most effective microorganisms againstB. cinerea in flower buds, reduced number of lesions in the range of 42–65% compared with 59–89% for à standard fungicide (vinclozolin). It is suggested that application of leading antagonists Jo living rose leaves and flowers should optimize control of inoculum production byB. cinerea when the tissues die. Optimal biocontrol of lesion production in flower buds requires a better understanding of the microenvironment of petals.     

A comparison of the autecology of Quercus robur L. and Q. pyrenaica Wild.: present habitat in Galicia, NW Spain

The biotopes occupied by pedunculate oak (Quercus robur L.)and rebollo oak (Quercus pyrenaica Willd.) in Galicia were characterizedusing different parameters, enabling a comparative analysisof its habitats. Thirty-nine plots of pedunculate oak and 40of rebollo oak were inventoried and 25 ecological parameters(physiographic, climatic and edaphic) were measured to describethe biotopes, along with 14 stand parameters to characterizethe structure and the silviculture of these forests; some ofthem were used in previous works about the autecology of bothspecies. Quercus robur was found to occupy a wider range ofecological habitats and their distribution is oceanic; Q. pyrenaicapresents a more Mediterranean phytoclimatic position. The resultsindicated that the distribution of oak forests in Galicia ismore closely related to physiographic and climatic featuresthan to edaphic, because the nature of the substrates that theyoccupy is similar. Analysis of fragility/aggressiveness betweenboth species and chestnut shows that the aggressiveness of bothoaks, mainly pedunculate, was much higher, except at high altitudes,and in areas with a high mean temperature, where rebollo ismore aggressiveness. Comparison of the two Quercus shows formost of the parameters that Q. robur is the more aggressivespecies.     

Microbial origin of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L.

The aetiological agents of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L., were studied. Four Vibrio strains were isolated from larvae of S. aurata affected by this disease, and all strains reproduced the disease in healthy larvae under controlled infection experiments, producing a significant increase of the mortality rates compared to the control (non-inoculated larvae). Several enzymatic properties, which can act as .virulence factors, were demonstrated both in the extracellular products (ECPs) and In live cells of the strains tested. Histopathological examinations of the infected fish larvae revealed important changes of the anterior intestine and liver characterized by a marked hyperthrophy of the intestinal epithelium and hepatocytes, and by a separation of the mucosal and submucosal layers in the digestive tube. These histological alterations were associated with the constant presence of cocobacillar bacteria in the anterior intestine and in the liver. However, the precise pathogenic mechanisms of the strains tested have not been completely elucidated yet.