Post-spawning feed deprivation effects on testicular and ovarian maturation in the neotropical cichlid fish Cichlasoma dimerus.

Many teleost fishes can withstand long feed deprivation periods, either due to an eventual lack of food or because of their behavior during reproduction and/or parental care. In this work, the effects of total food restriction on the oogenesis, spermatogenesis, and reproductive hormones of the neotropical cichlid fish Cichlasoma dimerus were studied. Specifically, different pairs were isolated after having a spawning event and were feed-deprived or daily fed for 3 weeks.

Morphological colour adaptation during development in fish: involvement of growth hormone receptor 1.

Morphological background adaptation is both an endocrine and a nervous response, involving changes in the amount of chromatophores and pigment concentration. However, whether this adaptation takes place at early developmental stages is largely unknown. Somatolactin (Sl) is a pituitary hormone present in fish, which has been associated to skin pigmentation.

GH, IGF-I and GH receptors mRNA expression in response to growth impairment following a food deprivation period in individually housed cichlid fish Cichlasoma dimerus.

Cichlasoma dimerus is a social cichlid fish capable of growing at high rates under laboratory conditions, but knowledge on somatic growth regulation is still unclear. Growth hormone (GH)/insulin-like growth factor I (IGF-I) axis is the key regulator of somatic growth in vertebrates. Two types of growth hormone receptors have been described in teleost fish, named GH receptor type 1 (GHR1) and type 2 (GHR2).