title: Biological variables of Hypostomus francisci (Siluriformes: Loricariidae) from Itapecerica River, Minas Gerais State, Brazil.
abstract: Herein we determine for the first time the reproduction parameters and population structure of Hypostomus francisci in the Itapecerica River, São Francisco Basin. A total of 250 specimens was captured quarterly between March 2010 and February 2012. Body weight, total length and weight of the gonads were obtained in the laboratory. Gonad samples were submitted to histological and histochemical techniques. Females with spawning capable ovaries were used to determine the fecundity and relative fecundity. Sex ratio with 1:1.01 (female:male) was observed. Males were more numerous than females for individuals smaller than 170 mm, however the number of females was significantly greater for specimens larger than 330 mm. The length-weight relationship estimated for H. francisci indicates negative-allometric growth. Females spawning capable were observed mostly in November-December-January. Two cohorts of oocytes at a determined time evidencing the development type group-synchronic. The eggs reaching 3.4 mm and the fecundity ranged from 312-1,460 oocytes with an average of 585.81 ± 337.43 oocytes per female. The reproductive parameters and population structure of H. francisci from Itapecerica River suggested that this species showed singular reproductive tactics among congeners.
authors.affiliation: Universidade Federal de São João Del Rei, Campus Centro Oeste, Laboratório de Processamento de Tecidos/LAPROTEC, Rua Sebastião Gonçalves Coelho, 400, 35501-296 Divinópolis, MG, Brasil.
authors.forename: Camila F
authors.initials: CF
authors.lastname: Sales
authors.affiliation: Universidade Federal de Ouro Preto, Instituto de Ciências Exatas e Biológicas, Rua Quatro, 786, 35400-000 Ouro Preto, MG, Brasil.
authors.forename: Fabrício Flávio T
authors.initials: FF
authors.lastname: Domingos
authors.affiliation: Universidade Federal de Minas Gerais, Departamento de Biologia Geral, Avenida Presidente Antônio Carlos, 6627, 31270-901 Belo Horizonte, MG, Brasil.
authors.forename: Ludmila S
authors.initials: LS
authors.lastname: Brighenti
authors.affiliation: Universidade Federal de São João Del Rei, Campus Centro Oeste, Laboratório de Patologia Experimental/LAPATEX, Rua Sebastião Gonçalves Coelho, 400, Chanadour, 35501-296 Divinópolis, MG, Brasil.
authors.forename: Rosy I M A
authors.initials: RI
authors.lastname: Ribeiro
authors.affiliation: Universidade Federal de São João Del Rei, Campus Centro Oeste, Laboratório de Processamento de Tecidos/LAPROTEC, Rua Sebastião Gonçalves Coelho, 400, 35501-296 Divinópolis, MG, Brasil.
authors.forename: Hélio B
authors.initials: HB
authors.lastname: Santos
authors.affiliation: Universidade Federal de São João Del Rei, Campus Centro Oeste, Laboratório de Processamento de Tecidos/LAPROTEC, Rua Sebastião Gonçalves Coelho, 400, 35501-296 Divinópolis, MG, Brasil.
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Thomé
mesh_terms: D000818:Animals; D049628:Body Size; D001835:Body Weight; D001938:Brazil; D002397:Catfishes / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D005298:Fertility; D006066:Gonads / Q000033:anatomy & histology; D008297:Male; D012098:Reproduction; D045483:Rivers; D012621:Seasons; D012737:Sex Factors