PURPOSE The authors examined the effects of both light and circadian phase on the synthetic activity of the dopamine producing enzyme, tyrosine hydroxylase (TH), in the retina of the Midas cichlid (Cichlasoma citrinellum). METHODS TH activity was assayed in the retina-retinal pigment epithelium (RPE) complex of fish entrained to cyclic light regimens. The animals were killed throughout cyclic...

In the retinas of many species of lower vertebrates, retinal photoreceptors and pigment epithelium pigment granules undergo daily movements in response to both diurnal, and in the case of teleost cone photoreceptors, endogenous circadian signals. Typically, these cone movements take place at dawn and at dusk when teleosts are maintained on a cyclic light (LD) regime, and at expected dawn and ex...

Objective- The present study describes the anesthetic effects of essential oil of Lavender (Lavandula officinalis) in Convict cichlid fish (Cichlasoma nigrofasciata) in comparison with clove powder (Syzygium aromaticum).Study Design- experimental studyAnimals- 25 Juvenile Convict cichlid fish with unknown sex and an average weight o...

Behavioral Efference is a hypothetical positive feedback from the performance of an aggressive display that augments the level of aggressive motivation. The hypothesis was proposed (Bond, 1989) to account for the occurrence of truthful communication during aggressive encounters, even in the face of a presumed selective pressure in favor of deceit (Maynard Smith, 1984). Evidence of Behavioral Ef...

Objective: In this survey, we have checked the effects of natural (red bell pepper and tomato) and synthetic (astaxanthin and β-carotene) pigments on bloods factors of Flower horn (Cichlasoma sp.). Methods: Five treatments (three replicates/treatment) were employed. Fishes were separated in fifteen equal groups and were fed for eight weeks with diets containing10 g kg–1 red ...