Sperm motility characteristics of wild Atlantic salmon (Salmo salar L.) and sea trout (Salmo trutta m. trutta L.) as a basis for milt selection

Abstract

The aim of the study was to determine the sperm motility parameters in wild Atlantic salmon and sea trout to define criteria important for selection of milt for controlled fertilisation. Parameters for these species were determined in the fish migrating into north-western rivers of Poland at spawning time. Eight motility parameters percentage of motile sperm (MOT), curvilinear velocity (VCL), average path velocity (VAP), straight line velocity (VSL), linearity (LIN), straightness (STR), amplitude of lateral head displacement (ALH), beat cross frequency (BCF) and motility duration were subjected to computer-assisted sperm analysis (CASA). Milt of most individuals studied representing both salmon and trout showed spermatozoa density of 12-22 · 10 9 ml )1 and a high percentage of motile sperm (>70%). In general, spermatozoa swim progressively with slightly curved trajectories (mean STR = 70%, LIN = 65%) and velocity VCL of 180 lm s )1 (salmon) and 190 lm s )1 (trout), at 10 s post-activation. Such sperm is easily accessible in the wild populations of salmon and sea trout and is recommended for use in reproduction trials. The spermatozoa of sea trout seem to show a greater tendency to follow curvilinear trajectories than those of salmon, both in the beginning and the final phase of motion. In the first phase of motility, the values and time dependencies of the motility parameters were similar in both species. In the end phase of movement differences in LIN and BCF time dependencies were found in the samples representing the two species. In salmon the linearity and beat cross frequency remained stable in this phase, contrary to the patterns in sea trout for which LIN decreased while BCF increased in the end period of movement. Durations of movement were similar in both species (ranges of 20-40 s).

<b>Cryopreservation of semen of Thailand tilapia (<i>Oreochromis</i> spp.) fed diet with different oil sources

“…Recent studies have been accomplished focusing the improvement of the potential of fish farming, but few studies have associated nutrition with reproductive parameters (EL-SAYED et al, 2005;BOMBARDELLI et al, 2010;NAVARRO et al, 2014).…”

“…These factors and the complexity of the cryopreservation process usually require developing species-specific protocol for cryopreservation (DZIEWULSKA et al, 2011).…”

“…The cryopreservation allows the sperm storage at −196°C for unlimited time, preserving its original conditions (CARNEIRO, 2007; VIVEIROS; GODINHO, 2009;DZIEWULSKA et al, 2011.…”

Comparative gonad histology and semen quality of normal (XY) and neo‐males (XX) of Atlantic salmon (Salmo salar)

“…Interestingly, the delayed maturity and non‐expression of semen by neo‐males, confers a practical advantage in their unmistakable selection from a mixed pool of normal and neo‐males, ensuring monosex (all female) seed production. However, the forced need to extract semen via gonad maceration contaminate mature semen with those immature and other impurities, conceivably accounting for relatively low fertilization efficiencies routinely encountered by hatchery managers (Dziewuslska et al, ; Trigo et al, ).…”

“…The videos were converted to required file format (*.avi, 10 frames/second) and then analysed using the ImageJ (Java) CASA plug‐in. Standardized handling methods and software configurations (Table ) suitable for Atlantic salmon semen (Dziewulska, Rzemieniecki, & Domagała, ; Parodi et al, ) were employed. The motility indices obtained were percentage of motile semen (MOT), percentage of linearity (LIN), progression (PROG, µm), straight line velocity (VSL, µm/s), curvilinear Velocity (VCL, µm/s), average path velocity (VAP, µm/s), percentage of wobble (WOB) and beat cross frequency (BCF, Hz; Gallego & Asturiano, ).…”