This article answers three questions of J. Almeida. Using combinatorial, algebraic and topological methods, we compute joins involving the pseudovariety of finite groups, the pseudovariety of semigroups in which each idempotent is a right zero and the pseudovariety generated by monoids M such that each idempotent of M\{1} is a left zero.

A nested polymerase chain reaction (PCR) assay was used to detect early stages of Myxobolus cerebralis in caudal and adipose fin samples from rainbow trout (RT). To determine sensitivity, groups of 10 RT were exposed to 2,000 M. cerebralis triactinomyxons/fish for 1 hour at 15 degrees C and subsequently moved to clean recirculating water. Fish were held for 2 and 6 hours and 1, 2, 3, 5, 7, 10, ...

The ascaridoid nematodes Dujardinascaris madagascariensis Chabaud & Caballero, 1966, Dujardinascaris dujardini (Travassos, 1920), Gedoelstascaris vandenbrandeni (Baylis, 1929) Sprent, 1978 and Multicaecum agile (Wedl, 1861) Baylis, 1923 were recovered from the stomach contents of Crocodylus niloticus Laurenti, 1768 from the Okavango River, Botswana, together with Eustrongylides sp., a dioctophy...

CIRKOVIC, M., N. MILOSEVIC, M. MARKOVIC and A. POTKONJAK, 2010. Brain myxoboliasis of common carp. Bulg. J. Agric. Sci., 16: 263-265 The common carp (Cyprinus carpio) originating from Serbian fish ponds was examined for presence of Myxobolus encephalicus. The spores of M. encephalicus were present in blood vessels and meningeal layers. Its presence has been noted in 32-days old carp fingerlings...

The hatchery and field performance of a whirling disease resistant strain of rainbow trout (Oncorhynchus mykiss) was compared to a traditional Utah strain: Ten Sleep (TS). The resistant strain consisted of progeny from a German strain (GR) x Harrison Lake strain (HA) backcrossed with the German strain, resulting in fish that were 3⁄4 German strain x 1⁄4 Harrison Lake strain. The disease resista...

Population and conservation genetics of two freshwater fish species, Notropis heterodon and Notropis heterolepis, were evaluated in north-eastern Illinois, U.S.A., where both species have severely declined. Fishes were sampled from two remnant populations occurring in small glacial lakes (source samples) and from two man-made ponds that had been stocked with fishes from those same lakes (sanctu...