The guppy and fish in the genus Xiphophorus have both been important model systems for the study of natural and sexual selection for over 50 years. Whereas the guppy is unique in the degree to which the environmental variables shaping phenotypic variation are known, Xiphophorus has the advantage that genomic resources have been developed due to the utility of this taxon for the study of melanom...

The major markets for ornamental fish are the Far East, the United States of America and the European Union (EU). Although the Far East is the principal source of both supply and demand for ornamental species, there is considerable movement of fish between these three areas. The author makes a detailed appraisal of the sources of supply and the destination for imports into EU Member States. Som...

The aim of this study was to perform various tests of the anesthetic efficacy of eugenol applied to different handling tasks such as artificial insemination, spawning induction, obtaining body weight and length, the conduct of operations, biopsies and transport of Xiphophorus helleri (Heckel, 1848). The tests were performed on 10 individual males and 10 individual females of X. helleri -1 (swor...

Fishes represent the stem vertebrate condition and have maintained several gene arrangements common to mammalian genomes throughout the 450 Myr of divergence from a common ancestor. One such syntenic arrangement includes the GPI-PEPD enzyme association on Xiphophorus linkage group IV and human chromosome 19. Previously we assigned the Xiphophorus homologue of the human ERCC2 gene to linkage gro...

The relative contribution of asymmetries in prior experience, size, and prior residency to the determination of dyadic dominance between unacquainted individuals was examined using pairs of green swordtail fish, Xiphophorus helleri. Four types of encounters were staged between an intruder and a smaller resident: (1) both had experienced prior victory; (2) both had experienced prior defeat; (3) ...