The purpose of this study was to verify the hypothesis of feminisation of the freshwater mussel Elliptio complanata exposed for one complete reproductive cycle (1 year) to a municipal effluent plume. Mussels were harvested from a reference lake and placed in specially-designed cages adapted for long-term exposure to a suspended matter-rich river environment. After exposure, mussels were collect...

The allometric relationship between body mass and gonad mass in males of 23 fish species from 11 families was examined. There was no evidence of a single allometry for all fishes. A cross species analysis suggested a scaling coefficient of 1 04, which was significantly different from a previous study that reported a scaling coefficient of 0 904. A within species analysis generated scaling coeff...

Most studies which aim at detecting effects of parasites on fish show that intermediate stages of parasites affect their host while adult parasites are usually less virulent in the final host. We studied the effect of the acanthocephalan Acanthocephaloides propinquus on one of its final hosts, the fish Gobius bucchichii. This study showed that the adult parasites affect host fitness. Moreover, ...

Gonadotropin-releasing hormone (GnRH) neurons in the preoptic area (POA) of the hypothalamus play a key role in regulating reproductive function. These neurons in turn are modulated by environmental influences, including the social environment. In both the Old World cichlid Astatotilapia burtoni and the New World cichlid Amatitlania nigrofasciatus, the size of the soma of GnRH expressing neuron...

Recently, Mozambique tilapia (Oreochromis mossambicus Peters, 1852) were listed on the IUCN Red List as near-threatened as their populations are at risk due to hybridization. Another factor that potentially contributes to their population decline is that they are regularly infected by the invasive parasitic copepod anchorworm, Lernaea cyprinacea Linnaeus, 1758. Considering anchorworm-infected M...

This study provides fundamental information on some key aspects of the reproductive traits of qanati tailor fish, Alburnoides qanati, an Iranian endemic, poorly studied cyprinid fish species. Sampling was performed on a monthly basis during one year (from March 2011 through February 2012) from a tributary of endorheic Kor River Basin, Southern Iran. The results of data analyzing showed that the...