In gadoid species, such as Atlantic cod, lipids are stored primarily in the liver [16] making liver weight a measure of spawner quality [17].
Thus, whilst gravel jetting could improve spawning gravel quality for surface spawning fishes, including European barbel Barbus barbus, its effects are short-lived.
In fish, a lack of PUFAs at various stages affects negatively the eye development, pigmentation, vertebrae development, fecundity, spawning, egg quality and larval hatching rates (Bell et al., 2003; Lall and Lewis-McCrea, 2007; Rainuzzo et al., 1997).
These conditions include quality spawn, temperature, humidity and consider the addition of an additive that is readily available, cheap and proven to increase yield and produce high quality G. frondosa in a short period of time (Montoya et al. 2012; Kraisit et al. 2017).
On Quatsino Sound beaches that experience Pacific herring spawn however, the quality of Traskorchestia spp. amphipods can be significantly influenced.
For example, hatchery fish might tend to return to spawning locations near their point of release, and if these locations happen to be in poor quality spawning habitat then the relative fitness of the hatchery fish would be reduced compared to wild fish spawning in higher quality habitat.
In teleosts, numerous nutritional-related factors such as feed ration, nutrient levels and compositions have been shown to influence various reproductive parameters such as gonadal development, gamete quantity and quality, spawning success, hatchability and larval quality (Izquierdo et al. 2001; Hachero-Cruzado et al. 2009).
Hazards One of the main hazards that may appear at this stage is the arrival of a spawn batch with poor quality, with contamination symptoms from pathogen or altering microorganisms.
There was no significant difference in the quality of spawns between treatment groups.
We highly recommend waiting for optimal reproductive potential of females at 12 months to enhance spawning frequency and larval quality.
The influence of two levels of water-flow rates (Low-Flow: 0.8 ± 0.05 L/s and High-Flow: 2.4 ± 0.05 L/s) on the spawning, fecundity and egg quality was also investigated.
