Description of the digestive tract and feeding habits of the king angelfish and the Cortes angelfish

Morphologically, the digestive tracts of the king angelfish Holacunthus passer and the Cortes angelfish Pomacanthus zonipectus are similar, yet the king angelfish intestine is almost 30% longer than that of the Cortes angelfish. Both pomacanthids have a small mouth with villiform teeth, a short oesophagus, a well-defined stomach, and a terminal sac at the end of the digestive tract. The terminal sac, the acid pH in the stomach, and the long intestine may facilitate efficient use of seaweed nutrients. Stomach contents were analysed to determine diets and interspecific overlap. Seventy-one species were found in the stomachs of the king angelfish and 53 in the stomachs of the Cortes angelfish. Because of the wide range of species in their diets, both angelfish must be regarded as omnivorous. The most frequent foods were seaweed and sponges, but for the king angelfish, crustaceans were also important. A cluster analysis was done to determine whether the diets of these fish were similar by sex, size, or season. No similarities were found. Dietary overlap is high in relation to other pomacanthids.     

IS6501-anchored PCR for the detection and identification of Brucella species and strains

A new strategy was developed to analyse the polymorphism of the genome of Brucella spp. All species of the Brucella genus contain several copies (between 10 and 40) of an insertion sequence, IS6501 (known also as IS711). The position of copies of this insertion sequence appears to differ in each species and this can be used to discriminate between them. A new polymerase chain reaction test, called IS-anchored-PCR (IS-an-PCR) was developed. It was based on a combination of a primer bound on the sequence of IS6501 with a second primer chosen arbitrarily. The patterns obtained reflect the position of the insertion sequence in the genome. This method can be used to identify Brucella and to discriminate between different species, strains within a species and between the vaccine strain B19 and the corresponding 'wild-type' B. abortus A1.