Renal myxozoanosis in weedy sea dragons, Phyllopteryx taeniolatus (Lacepède), caused by Sinuolinea phyllopteryxa n. sp.

Renal myxozoanosis was diagnosed histologically in 11 captive, wild caught, adult weedy (common) sea dragons, Phyllopteryx taeniolatus, from three separate public aquaria in the United States. Myxozoan spores were visible in wet mounts of kidney tissue and were associated with renal tubular dilatation and tubular epithelial cell hypertrophy. Light and electron microscopy revealed spore morphology consistent with the genus Sinuolinea. Spores were spheroidal, slightly dorso-ventrally compressed, length (L) 17.1 x width (W) 16.4 x thickness (T) 15.6 microm, with two shell valves joined at a distinct, sinuous sutural ridge, and had two nearly spherical polar capsules, L 5.5 x W 5.0 microm, with five to seven turns of the polar filament. There were no extra-valvular ridges or protrusions. DNA sequencing required the design of three new primers that yielded 1740 bp of 18S ribosomal DNA sequence. The parasite was determined to be novel based on morphological and molecular data, and was given the name Sinuolinea phyllopteryxa after its vertebrate host.     

Photosynthetic pathway and biomass energy production

The current interest in locating new or alternative sources of energy has focused attention on solar energy capture by crops that can be subsequently utilized as a substitute for fossil fuels. The very high productivity of sugarepane and the fact that it accumulates sugars that are directly fermentable to alcohol may have caused seemingly less productive crops to be overlooked. We show here that recoverable alcohol from achievable commercial yields of pineapple can actually equal that of sugarcane, with the pineapple crop requiring only a fraction of the water used by sugarcane. Pineapple is well adapted to the subhumid or semiarid tropics and thus is particularly well suited for exploiting large areas not now under cultivation with any crop of commercial value.     

Economic profitability of Nile tilapia (Oreochromis niloticus L.) production in Kenya

Economic profitability of Nile tilapia production in Kenya was analysed using a model that simulated individual fish growth and took fish population dynamics in the pond into account. The results suggest that the currently practiced mixed‐sex tilapia culture is economically unsustainable. It is suggested that research and extension efforts be geared towards developing monosex Nile tilapia production systems. Nile tilapia culture with African catfish predation should be viewed as an intermediate step towards all‐male Nile tilapia culture. This will allow accumulation of both physical and human capital to support all‐male tilapia culture. Under all‐male culture, economic returns are high enough to justify investment in Nile tilapia culture using borrowed capital. However, the success of monosex culture will depend on the availability and affordability of quality fingerlings and low‐cost fish feeds. The results have a wide application in Sub‐Saharan Africa where mixed‐sex Nile tilapia culture is common.     

Surface ices and the atmospheric composition of pluto

Observations of the 1.4- to 2.4-micrometer spectrum of Pluto reveal absorptions of carbon monoxide and nitrogen ices and confirm the presence of solid methane. Frozen nitrogen is more abundant than the other two ices by a factor of about 50; gaseous nitrogen must therefore be the major atmospheric constituent. The absence of carbon dioxide absorptions is one of several differences between the spectra of Pluto and Triton in this region. Both worlds carry information about the composition of the solar nebula and the processes by which icy planetesimals formed.     

Clostridium botulinum type B toxicosis in a herd of cattle and a group of mules

Clostridium botulinum type B toxicosis was diagnosed as the cause of generalized weakness and death in a group of cows and mules fed from the same batch of rye silage. One severely affected cow was treated and recovered, as did other less severely affected cows. All affected mules died. The remaining cattle in the herd were then vaccinated before continued feeding of the silage.     

Predicted Redistribution of Ceratomyxa shasta Genotypes with Salmonid Passage in the Deschutes River,Oregon

Abstract

A series of dams on the Deschutes River, Oregon, act as migration barriers that segregate the river system into upper and lower basins. Proposed fish passage between basins would reunite populations of native potamodromous fish and allow anadromous fish of Deschutes River origin access to the upper basin. We assessed the potential redistribution of host-species-specific genotypes (O, I, II, III) of the myxozoan parasite Ceratomyxa shasta that could occur with fish passage and examined the influence of nonnative fish on genotype composition. To determine the present distribution of the parasite genotypes, we exposed eight salmonid species—three native and five stocked for sport fishing—in present and predicted anadromous salmonid habitats. We monitored fish for infection by C. shasta and sequenced a section of the parasite ribosomal DNA gene from fish and water samples to determine parasite genotype. Genotype O was present in both upper and lower basins and detected only in steelhead Oncorhynchus mykiss. Genotype I was spatially limited to the lower basin, isolated predominately from Chinook salmon O. tshawytscha, and lethal for this species only. Genotype II was detected in both basins and in multiple species, but only as a minor component of the infection. Genotype III was also present in both basins, had a wide host range, and caused mortality in native steelhead and multiple nonnative species. Atlantic salmon Salmo salar and kokanee O. nerka were the least susceptible to infection by any genotype of C. shasta. Our findings confirmed the host-specific patterns of C. shasta infections and indicated that passage of Chinook salmon would probably spread genotype I into the upper Deschutes River basin, but with little risk to native salmonid populations.

Received April 20, 2012; accepted July 19, 2012