Filtration of Green Algae and Cyanobacteria by Freshwater Mussels in the Partitioned Aquaculture System

Abstract.— The freshwater mussel Elliptio complanata was provided water containing green algae and cyanobacteria delivered from the Partitioned Aquaculture System (PAS) at eight flow rates to determine algal filtration rates as mg of particulate organic carbon (POC)/kg wet tissue weight per h. The dominant taxon in cyanobacterial waters was Microcystis while the dominant taxa in green algal waters were Scenedesmus and Ankistrodesmus . The cell counts of Scenedesmus and Ankistrodesmus were the only algal taxa that were significantly different between the incoming water and water filtered by mussels. Filtration rates of POC obtained from green algal water were significantly greater than from cyanobacteria-dominated waters at all flow rates. A significant increase in mean filtration rate was observed as flow rates increased. The filtration rate of green algae increased as POC concentration increased, peaking at 28 mg C/L. A maximum filtration rate was not observed with cyanobacterial waters.     

Preliminary investigations into factors that affect plasma aldosterone concentrations in horses

The effect of feeding diets with low, adequate and high sodium contents on plasma aldosterone concentrations in horses and ponies was evaluated using human immunoassay kits. The effect of moderate to high intensity exercise of up to six minutes duration on plasma aldosterone concentrations in three thoroughbred- horses was also investigated. On an adequate sodium diet plasma aldosterone concentrations increased to a peak around four hours after feeding. Little daily variation was found in the pre-feeding aldosterone concentrations over three days. Feeding additional salt resulted initially in no increase in plasma aldosterone concentrations in three out of four animals. After five days all four animals had lower pre-feeding concentrations, an increase in the magnitude of the response to feeding but a decreased rise in absolute concentration. Feeding a diet with a decreased sodium content for several months did not result in a consistent change in the pre-feeding aldosterone concentrations although there were times when all three animals showed an increase in the magnitude of the aldosterone response to feeding. No correlation between changes in the fractional electrolyte excretion values determined and alterations in aldosterone response was found. Exercise resulted in a marked increase in aldosterone concentrations. The expected biological response to feeding and exercise was demonstrated with an acceptable level of reproducibility and repeatability. Samples had similar values when assayed by either of the kits evaluated.     

Releases in israel ofAphelinus perpallidus,a recently introduced parasite of the pecan blackmargined aphid,Monellia caryella

Six shipments totaling 3452 mummies of the blackmargined aphid,Monellia caryella (Fitch), parasitized withAphelinus perpallidus Gahan, were obtained by air freight during the years 1982-1985 from Texas A&M Research Center, El Paso, Texas. About two-thirds of the mummies did not yield parasites. A colony ofA. perpallidus was established in the laboratory. Under laboratory conditions the percentage of emerged parasites was higher than that in the imported mummies, and the parasite had very limited impact on the aphid population. Field releases of the parasite were made but no establishment ofA. perpallidus was observed through the years.     

Lung sounds in cattle, horses, sheep and goats

The purpose of this paper is to emphasize the importance of pulmonary auscultation for the clinician. It suggests a clarification and simplification of the terminology to be used which would be helpful to veterinary students and allow better communications between veterinarians. The interpretation of these sounds and the relationships to conditions and diseases of the lungs in cattle, horses, sheep and goats are discussed.     

Prevalence of Mycoplasma agassizii and Chelonian herpesvirus in captive tortoises (Testudo sp.) in the United Kingdom.

During the months of April to August in 1999 and 2002, oral swabs were collected from 146 tortoises (Testudo sp.) in private collections in the United Kingdom and tested by polymerase chain reaction (PCR) for the presence of Mycoplasma agassizii and Chelonian herpesvirus (ChHV). The presence of M. agassizii was confirmed by restriction digestion of the PCR product. A 307-bp fragment of the ChHV UL5 homologue gene was sequenced and found to show most similarity to equine herpesvirus type 1. A prevalence of 15.8 and 8.2% was found for M. agassizii and ChHV, respectively. Comparison of the carriage of both M. agassizii and ChHV in different species of tortoises correlated the presence of M. agassizii with Testudo horsfieldii and ChHV with Testudo marginata and Testudo graeca iberia. An association of ChHV with stomatitis was also found. Mixed infections with both agents were detected. The findings further demonstrate this pathogen-tortoise association and the cross transmission of these infections if different tortoise species are housed together.     

Micromorphology of soils in soliflucted materials,Okstindan, Northern Norway

The micromorphology of two soil profiles developed on turf-banked solifluction lobes and a third profile formed on a larger turf-banked solifluction terrace is described. Four elements common to the three profiles are identified.In the horizontal plane the apparent long axes of detrital grains show preferred orientation parallel to the azimuth of the line of greatest slope, and in slides cut in the vertical plane aligned with the slope direction a somewhat stronger preferred orientation (or apparent dip of the grains) is observed parallel, or sub-parallel to the ground surface gradient. Secondly, coatings of matrix material are observed on the upper surfaces of detrital grains at depths greater than 50 cm. Above this depth similar coatings also appear on the sides and lower surfaces of detrital grains. Roughly horizontal flattened patches of matrix enrichment are also observed in the three profiles. These become more frequent with depth, producing a banded pattern of matrix concentrations separated by detrital grains. Finally, large rounded pores, or vesicles, are observed in the upper 25 cm of the three profiles.These micromorphological elements are described, and suggestions are made as to their origins.