title: Hormonal induction and semen characteristics of tambaqui Colossoma macropomum.
abstract: In the hatchery-bred tambaqui Colossoma macropomum, spontaneous semen release does not occur, and hand-stripping produces reduced semen volume. The goal of this work is to evaluate the effects of hormonal induction with carp pituitary extract (CPE) on both qualitative (visual aspect, pH, motility, viability and morphological abnormalities) and quantitative (volume, concentration and number of spermatozoa per ejaculate) traits of tambaqui semen. Eleven males were treated with CPE (induced), and 11 were left untreated as a control (non-induced). All analysed parameters except motility and percentage of viable spermatozoa presented significant differences (p < 0.05) between the induced and non-induced treatments. CPE induction resulted in a 25-fold increase in semen volume and a 10-fold increase in the number of spermatozoa collected. However, both sperm concentration and the frequency of sperm with morphological abnormalities (commonly detached heads or bent tails) were significantly lower in CPE-induced fish. The hormonal induction of tambaqui males with CPE is efficient and positively influences some qualitative and quantitative properties of semen. Additionally, semen collection via gentle abdominal massage occurs more readily in CPE-induced fish.
authors.affiliation: Laboratório de Biotecnologia da Reprodução Animal, Embrapa Tabuleiros Costeiros, Av. Beira Mar 3250, Aracaju, SE, Brazil.
authors.forename: Alexandre Nizio
authors.initials: AN
authors.lastname: Maria
authors.forename: Hymerson Costa
authors.initials: HC
authors.lastname: Azevedo
authors.forename: Jadson Pinheiro
authors.initials: JP
authors.lastname: Santos
authors.forename: Paulo César Falanghe
authors.initials: PC
authors.lastname: Carneiro
mesh_terms: D000818:Animals; D002347:Carps / Q000502:physiology*; D004542:Ejaculation; D006863:Hydrogen-Ion Concentration; D007273:Injections, Intramuscular; D008297:Male; D010907:Pituitary Hormones / Q000008:administration & dosage / Q000494:pharmacology*; D012661:Semen / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D013076:Sperm Count; D013079:Sperm Maturation; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology
chemical_list: D010907:Pituitary Hormones