Effects of cooling rates on the quality of Prochilodus lineatus (Valenciennes, 1836) sperm

Abstract

This study aims to investigate the effect of different cooling rates on the semen cryopreservation of curimba (Prochilodus lineatus). Nineteen ejaculates were obtained from adults males and cryopreserved at 15°C/min (CR15), 30°C/min (CR30) (controlled temperature inside and outside straw, speed was stable during freezing) and direct freezing in liquid nitrogen vapour (~35.6°C/min) (CRNV). The straws were thawed and seminal parameters evaluated. DNA fragmentation through the comet assay was assessed. A fresh sperm sample was not frozen and used for analyses. Data were submitted to an analysis of variance (ANOVA), and means were compared by Scott–Knott test (p < 0.05) using the R Software. Mean motility percentage was 100%, and motility duration was 39.5 ± 5.7 s for the fresh sperm (subjective analysis); 58.9 ± 8.0% and 24.5 ± 5.7 s for CR15; 64.8 ± 4.8% and 26.5 ± 7.1 s for CR30; and 50.1 ± 16% and 25.7 ± 4.7 s for CRNV, respectively. Motility percentages were higher and equal between CR15 and CR30 compared to CRNV (p < 0.05). Some sperm motion kinetics, namely average path velocity (VAP) and straight line velocity (VAS), were higher for CR30 (p < 0.05), while curvilinear velocity (VCL) and velocity progression (PRO) were lower for CRNV (p < 0.05). Straightness (STR) and wobble (WOB) were the same among treatments (p > 0.05). Sperm morphology results indicated higher means for total morphological sperm alterations in CRNV. All cooling rates caused sperm DNA fragmentation, although CR30 provided a less harmful effect. This is the first report for cryopreserved P. lineatus sperm preserved under different controlled cooling rates. The cooling rate of 30°C/min is indicated for the cryopreservation of this fish sperm as it led to the lowest detrimental spermatozoa effects.

Sperm cryopreservation of Prochilodus lineatus throughout the same reproductive season

“…The effects of cryopreservation on fish sperm have been addressed by different authors (Figueroa et al, 2019; Paula et al, 2019; Shaliutina‐Kolešová et al, 2015; Wang et al, 2016) with the objective to improve the use of this tool. In the present work, the association between techniques to study Prochilodus lineatus post‐thaw sperm throughout the reproductive season permitted a better understanding of sperm physiology.…”

“…The streaked prochilod Prochilodus lineatus (Prochilodontidae, Characiformes) is a migratory neotropical fish with a large distribution in the main hydrographic basins of South America (Castro & Vari, 2004). This species is well adapted to captivity and has been used in reproduction studies (Machado et al, 2019; Miliorini et al, 2011; Paula et al, 2019), proving it can be used as a model species for the study of other neotropical fish species, which are considered endangered. The annual migration and spawn of the P. lineatus occur during the rainy months when water levels rise, water temperatures are higher, and the day length is longer (Vazzoler et al, 1997).…”

Responses of aquaculture fish to climate change‐induced extreme temperatures: A review

“…In Northern pike, Esox lucius (Cejko, Krejszeff, Judycka, Targońska, & Kucharczyk, 2019), Atlantic salmon, S. salar (Taranger et al, 2003), rainbow trout, O. mykiss (Dadras, Dzyuba, Golpour, Xin, & Dzyuba, 2019) and hound, Mustelus schmitti (Elisio, Awruch, Massa, Macchi, & Somoza, 2019) inhibition of spermiation was observed during elevated temperature exposure. Sperm motility and quality were also affected by climate change‐induced temperatures in coruh trout, Salmo coruhensis (Tunçelli & Memiş, 2020), rainbow trout, O. mykiss (Dadras et al, 2019), sturgeon, A. brevirostrum (Gilroy & Litvak, 2019) and streaked prochilod, Prochilodus lineatus (Paula et al, 2019). Thus, from the above discussion we can assume that growth, reproductive performance, and physiological fitness of aquaculture species in captive environments and the wild will be affected by climate change‐driven extreme temperature events.…”