Criopreservação de sêmen de Jundiá, Rhamdia voulezi e r. branneri (Siluriformes: heptapteridae) utilizando diferentes crioprotetores

Abstract

The species of catfish Rhamdia branneri and R. voulezi are endemic to the Iguaçu River Basin and have favorable characteristics which are interesting for fish farming. Semen cryopreservation technology has been widely used in aquaculture, especially in breeding and genetic conservation of endangered species. For these species had not yet studies on the subject. Thus, the objective was to conduct studies in order to compare different intracellular and extracellular cryoprotectants in semen cryopreservation catfish R. branneri and R. voulezi. Four cryoprotectant solution containing 10% of anhydrous glucose were tested (C6H12O6) as diluent. Solutions: 1 - DMSO (C2H6OS) and 10% egg yolk; 2 - methanol (CH3OH) 10% and 5% powdered milk; 3 - glycerol (C3H8O3) and 10% egg yolk and 4 - 10% glycerol and 5% milk powder, respectively intra and extracellular protector. Semen was collected and each species motility test performed for each sample, resulting in higher motility than 30 seconds considering just viable cryopreservation. Was performed semen pool of three males of R. voulezi and two males of R. branneri before submitting freezing, the solutions were tested ensuring the non-occurrence of activation by the extender solution. The activator solution was tested distilled water. The solution 1, containing DMSO was not effective for both species, showing no sperm motility after activation. For the motility time of R. voulezi the cryoprotectant solutions methanol + milk and glycerol + egg were similar to each other and higher glycerol + milk (P<0.05). For R. branneri the three solutions were efficient in cryopreservation no significant difference (P>0.05) for the time variable motility. Assessing the motility intensity scale, the best result was obtained by glycerol + egg solution to R. branneri and equating to the glycerol + milk to R. voulezi. The semen R. branneri and R. voulezi can be cryopreserved with the solutions presented except the use of DMSO. The best extender solution in sperm motility for these species is glycerol + egg.