Spawning induction and fecundity of commercial native fish species from the São Francisco River basin, Brazil, under hatchery conditions

In order to exploit native fish species for aquaculture, basic parameters of artificial reproducetion and estimates of reproductive potential for this fish must be determined to improve hatchery success. We analyze seven Brazilian commercial fish. Spawning was induced using the hypophysation method, with injection of crude carp pituitary extract (CCPE). Characiformes species signaled the spawning time with behavioral alterations (usually circular movements). The time of oocyte extrusion varied from 5.3 ± 0.3 h in Salminus franciscanus to 8.6 ± 0.1 h in Prochilodus argenteus after the second CCPE injection. The greatest diameter of a vitellogenic oocyte was registered for P. argenteus (873.9 ± 122.2 μm) and the smallest was for Pimelodus maculates (465.4 ± 36.3 μm). The diameter of vitellogenic oocytes was very similar among species belonging to the same family. The highest ROI values were registered for Prochilodus costatus(27.0 ± 3.5 μm) and P. argenteus (23.4 ± 3.7 μm), while the lowest values were found in Pseudoplatystoma corruscans (4.6 ± 0.9 μm) and P. maculatus (6.0 ± 1.3 μm). Absolute fecundity (number of oocytes released at spawning) was lowest in P. maculatus and highest in P. corruscans. Relative fecundity (RF) presented a high correlation (r = 0.98 to 0.99) with gonad weight, indicating high efficiency of spawning. The RF also presented a high correlation with body weight (r = 0.88 to 0.97) and total length (r = 0.86 to 0.92). The highest RF was registered for Leporinus obtusidens, and the lowest was for P. corruscans. Released fecundity had a negative correlation with the diameter of vitellogenic oocytes and with the height of the follicular cells, and a positive correlation with the thickness of the zona pelucida. These results indicate that the species studied herein are suitable candidates for aquaculture due to their reproductive and zootechnical characteristics.