Semen characteristics of Colossoma macropomum from three successive sample collections in the same reproductive cycle

Abstract

The objective of this work was to evaluate the semen characteristics of C. macropomum fish from three successive semen sample collections taken during the same reproductive cycle. Six breeders (6.4 AE 1.5 kg) induced with crude carp pituitary extract (2.5 mg kg À1 ) were used. Samples of semen were collected in graduated syringes after a period of 260 degree-hours. The semen was collected from the same males in September 2014 (sample 1), December 2014 (64 days after the first collectionsample 2) and February 2015 (86 days after the second collectionsample 3). The semen volume was higher (P < 0.05) in the sample 1 (6.7 mL) and sample 2 (3.4 mL) than in the sample 3 (1.0 mL). Sperm concentration and normal sperm did not significantly differ between samples. Likewise, sperm motility, curvilinear velocity, displacement velocity, oscillation and beat cross frequency did not vary, whereas straight-line velocity, straightness and progression were higher (P < 0.05) in sample 2 (December). In general, despite lower amounts, the semen appeared to be of good quality for all three samples collected during the same reproductive period.

Sperm quality of Colossoma macropomum after room‐temperature and cold storage

“…In addition to MOT, VCL, VAP and VSL are important sperm characteristics that can affect fertility. Values for these characteristics in the present study were similar to those obtained by Pires et al (). The association of these characteristics with fertility has not been established for C. macropomum .…”

“…The initial MOT of the sperm (98.2%) observed in the present study for the different treatments was close to that reported by Pires et al () (96.5%) and Gallego et al () (96.0%) (also using casa computer software) for C. macropomum immediately after semen collection. Therefore, the initial MOT observed in the present study was within the range expected for this species.…”

“…Although WOB was similar between the storage methods (except at 10 hr), only cooled semen showed WOB at 35 hr. The WOB of sperm cooled for 25 and 35 hr was close to those obtained by Pires et al () (82.9%) and Gallego et al () (85.0%) immediately after semen collection, suggesting that the semen quality was maintained even after this storage period, considering this characteristic.…”

“…These data indicate that semen quality improves when it is cooled during the storage times tested in this study. These values (even at 35 hr of cooling) were higher than the 72.6% observed by Pires et al () in the same species immediately after semen collection.…”

“…There are several studies on the reproduction of C. macropomum (Maria, Azevedo, Santos, & Carneiro, ; Martins et al, ; Varela Jr et al, ), some of which even examined sperm quality using ( casa ) in fresh sperm (Gallego et al, ; Maria et al, ; Melo‐Maciel, Nunes et al, ; Pires et al, ) and cryopreserved sperm (Gallego et al, ; Melo‐Maciel, Leite‐Castro et al, ). However, there are no reports on evaluation using casa software on the quality of cooled semen of C. macropomum .…”