In 2014, infectious spleen and kidney necrosis virus (ISKNV), a member of the genus Megalocytivirus, was detected for the first time in ornamental fish in Germany. Since 2013, angelfish Pterophyllum spp. originating from Colombia have experienced significant epizootics in a number of German retailers' facilities. The diseased fish showed symptoms such as increased ventilation, swollen gills, an...

The evolution of complex signals via sexual selection is becoming a primary focus in mate choice studies. Male swordtail fish, Xiphophorus helleri, have a secondary sexual trait, the sword, which is a composite trait consisting of four components favoured by sexual selection via female mate choice. The components include three coloured stripes and size. Although a complete sword is most attract...

Several species of the genus Xiphophorus are polymorphic for specific pigment patterns. Some of these give rise to malignant melanoma following the appropriate crossings. For one of these pattern loci from the playfish Xiphophorus maculatus the melanoma-inducing gene has been cloned and found to encode a novel receptor tyrosine kinase, designated Xmrk. Using molecular probes from this gene in S...

The handicap theory of sexual selection posits that male display traits that are favored in mate choice come at a significant cost to performance. We tested one facet of this hypothesis in the green swordtail (Xiphophorus helleri). In this species, the lower ray of male caudal fin is extended into a 'sword', which serves to attract potential mates. However, bearing a long sword may increase dra...

To evaluate the effects of three non-conventional insects (cricket, grasshopper and mealworm) commercial diet (control) on growth, survival total carotenoid content ornamental fish, platy (Xiphophorus maculatus), a feeding trial was conducted in Zoology laboratory, Vidyasagar College, West Bengal, India, between November 2021 May 2022. A 250 juveniles (0.04±0.002 gm) were stocked 12 glass aquar...