Banca de DEFESA: RENATA CATAO EGGER

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: RENATA CATAO EGGER
DATA: 22/08/2019
HORA: 16:30
LOCAL: Sala de Reuniões PPGCV
TÍTULO:

Sperm cryopreservation throughout the spawning season in Prochilodus lineatus 

PALAVRAS-CHAVES:

Semen. Motility. Oxidative stress. Morphology. Neotropical fish.

PÁGINAS: 50
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
RESUMO:

Understanding the biology of fish species is crucial for fish culture. Association between the knowledge on fish reproductive biology and artificial propagation techniques improves fish production for both aquaculture and restocking programs. The aim of this study was to determine the quality of Prochilodus lineatus sperm cryopreserved throughout the spawning season (November to March). Males (n=43) were hand-stripped after carp pituitary treatment. Fresh sperm was subjectively analyzed for its motility rate, motility quality score, duration of motility and morphology. Semen was cryopreserved on 0.5 mL straws (n=258) using methyl glycol as cryoprotectant and glucose solution as extender. Post-thaw sperm was analyzed for its motility rate, velocities (curvilinear – VCL; straight-line – VSL; average path – VAP), and beat cross frequency (BCF) using a Computer-Assisted Sperm Analyzer (CASA). Frozen sperm morphology, oxidative stress (lipid peroxidation – LPO; reactive oxygen species – ROS; superoxide dismutase – SOD; catalase – CAT), and fertilization capacity (fertilization and hatching rates) were also evaluated. Seminal plasma was analyzed for pH, osmolality and ion concentration (Na⁺, K⁺, Ca²⁺ and Mg²⁺). P. lineatus fresh sperm presented good quality during the reproductive period, and sperm freezing ability was affected throughout the spawning season. Post-thaw sperm yielded higher motility and VCL on December to March. During this same period, CAT activity and sperm concentration were lower. Negative correlations were observed between sperm concentration and frozen sperm motility, sperm concentration and VCL, and Ca²⁺ concentration on seminal plasma and frozen sperm motility. Positive correlations were observed between sperm concentration and Ca²⁺ concentration on seminal plasma, and sperm concentration and CAT activity. A positive correlation was also observed between the minimum temperatures and LPO, indicating that climate factors influenced cryopreserved sperm. The lower temperatures registered before the spawning season negatively affected the quality of the sperm frozen at the beginning of the reproductive period (reduced motility rates and VCL observed on November). Although both fresh and post-thaw semen presented a lower percentage of normal sperm cells on March, samples yielded good quality parameters such as motility rate, motility quality score, and VCL on this month. Fertilization and hatching rates were similar throughout the spawning season. P. lineatus sperm cryopreserved from December to March presents better quality. Post-thaw sperm quality is influenced by seminal plasma ion composition, oxidative stress-related damage and climate factors. 

MEMBROS DA BANCA:
Presidente - LUIS DAVID SOLIS MURGAS (Membro)
Externo ao Programa - MARCOS FERRANTE - DMV (Suplente)
Externo ao Programa - CRISTINA DELARETE DRUMMOND - DSA (Membro)
Externo à Instituição - ALINE FERREIRA SOUZA DE CARVALHO - UNINCOR (Suplente)
Externo à Instituição - ALEXMILIANO VOGEL DE OLIVEIRA - EPAMIG (Membro)