Fish sperm subpopulations: Changes after cryopreservation process and relationship with fertilization success in tambaqui (Colossoma macropomum).
Fish tambaqui (Colossoma macropomum) is the native Brazilian fish with the highest agricultural production under intensive aquaculture in South America. However, the decrease in the genetic variability in fish farms has become necessary the improvement of cryopreservation process through new statistical studies of spermatozoa (like subpopulation studies). The evaluation of the kinetic data obtained with a computer-assisted sperm analysis system, applying a two-step cluster analysis, yielded in tambaqui three different subpopulations in fresh sperm: SP1, considered as a slow nonlinear subpopulation; SP2, considered as a fast nonlinear subpopulation, and finally; SP3, considered as a fast linear subpopulation. For cryopreserved sperm, the cluster analysis yielded only two sperm subpopulations: SP1', considered as a slow nonlinear subpopulation and SP2', which seemed to be an intermediate subpopulation (showing medium motility and velocity values) merged from SP2 and SP3 obtained from fresh sperm. Coefficients of correlation (r) and determination (r2) between the sperm subpopulations from fresh sperm and the fertilization rates were calculated, and SP2 and SP3 (the fast-spermatozoa subpopulations) showed a high-positive correlation with the fertilization rates (r = 0.93 and 0.79, respectively). In addition, the positive significant correlations found in curvilinear velocity (r = 0.78), straight line velocity (r = 0.57), and average velocity (r = 0.75) indicate that sperm kinetic features seem to be a key factor in the fertilization process in tambaqui, as occur in other fish species.
Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Valencia, Spain; Animal Reproduction and Biotechnology Laboratory - Embrapa Tabuleiros Costeiros, Aracaju, SE, Brazil.
V
V
Gallego
Programa de Pós-graduação em Zootecnia, Universidade Federal de Sergipe, São Cristovão, SE, Brazil.
S S
SS
Cavalcante
Animal Reproduction and Biotechnology Laboratory - Embrapa Tabuleiros Costeiros, Aracaju, SE, Brazil.
R Y
RY
Fujimoto
Animal Reproduction and Biotechnology Laboratory - Embrapa Tabuleiros Costeiros, Aracaju, SE, Brazil.
P C F
PCF
Carneiro
Animal Reproduction and Biotechnology Laboratory - Embrapa Tabuleiros Costeiros, Aracaju, SE, Brazil.
H C
HC
Azevedo
Animal Reproduction and Biotechnology Laboratory - Embrapa Tabuleiros Costeiros, Aracaju, SE, Brazil. Electronic address: alexandre.maria@embrapa.br.
A N
AN
Maria
D000818:Animals; D015415:Biomarkers; D015925:Cryopreservation / Q000662:veterinary*; D005260:Female; D005298:Fertility; D005306:Fertilization; D005399:Fishes / Q000502:physiology*; D008297:Male; D010063:Ovum; D012661:Semen / Q000502:physiology; D012662:Semen Preservation / Q000662:veterinary*; D013081:Sperm Motility; D013094:Spermatozoa / Q000145:classification / Q000502:physiology*
D015415:Biomarkers
CASA; Kinetic parameters; Motility; Sperm quality; Velocity