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Atasever, M., & Bozkurt, Y. (2015). Effect of Different Photoperiod Regimes on Sperm Quality, Fecundity and Fertilization in Rainbow Trout (Oncorhynchus mykiss). Turk. J. Fish. Aquat. Sci., 15, 517–523.
Abstract: The present study was carried out to determine effect of different photoperiod regimes on sperm quality parameters,
ovulation/spermiation time and hatchery performance of rainbow trout (Oncorhynchus mykiss) broodstock. The designation
was done as combination of different long and short photoperiod regimes such as: 18L:6D and 18D:6L (group I); 14L:10D
and 14D:10L (group II) and natural lighting (control group). All treatments were carried out as three replications at each
As a result, the highest mean spermatozoa motility (83.0Â±2.1 %) and motility period (67.2Â±6.3 s) were determined in
control group. It was determined that the longest ovulation was occured in female rainbow trout broodstock at 265 days in
group I. Although the highest mean absolute egg productivity was determined as 3654.7Â±298.3 eggs/fish in group I, the
highest mean relative egg productivity was determined as 137.3Â±24.5 eggs/kg in control group. Furthermore, the highest mean
egg diameter (4.6Â±0.1 mm) and fertilization rate (87.0Â±2.5 %) were determined in control group. Statistical analyses revealed
that spermatozoa motility, spermatozoa motility period and spermatozoa density positively correlated with fertilization rate in
all photoperiod regimes (P>0.05). On the other hand, semen volume and semen pH negatively correlated with fertilization rate
in all photoperiod regimes (P>0.05). It is interesting to note that only statistically important positive correlation was
determined between relative fecundity and fertilization rate in 18L:6D/18D:6L photoperiod regime (r=0.452, P<0.05).
Consequently, results revealed that combined long and short artificial photoperiod regimes can advance ovulation and
spermiation and also can effect gamete quality and hatchery performance of rainbow trout during out-of-season spawning.
Bapary, M. A. J., Amin, M. N., Takeuchi, Y., & Takemura, A. (2011). The stimulatory effects of long wavelengths of light on the ovarian development in the tropical damselfish, Chrysiptera cyanea. Aquaculture, 314(1-4), 188–192.
Becker, A., Whitfield, A. K., Cowley, P. D., Järnegren, J., Naesje, T. F., & Crispo, E. (2013). Potential effects of artificial light associated with anthropogenic infrastructure on the abundance and foraging behaviour of estuary-associated fishes. J Appl Ecol, 50(1), 43–50.
Abstract: As a consequence of a positive phototaxic response, the findings of this study suggest that artificial light often associated with man-made structures has the potential to alter fish communities within urban estuarine ecosystems by creating optimal conditions for predators. Future coastal developments should consider the ecological implications of lighting on aquatic communities. We recommend that lighting be minimized around coastal infrastructure and the use of red lights, which have limited penetration though water, be considered.
Bos, A. R., & Gumanao, G. S. (2012). The lunar cycle determines availability of coral-reef fishes at fish markets. J Fish Biol, 81(6), 2074–2079.
Abstract: During 139 visits between March 2009 and May 2011, it was found that the availability of reef fishes at a local fish market in the Philippines was highly affected by the lunar cycle. The number of vendors selling reef fishes was significantly lower (13.4%) during third lunar quarters (full moon periods) than during the first, second and fourth lunar quarters (40.2, 25.0 and 30.0%, respectively). It is recommended that the influence of the lunar cycle on fish availability is considered when designing sampling strategies for catch surveys.
Bramm, M. E., Lassen, M. K., Liboriussen, L., Richardson, K., Ventura, M., & Jeppesen, E. (2009). The role of light for fish-zooplankton-phytoplankton interactions during winter in shallow lakes – a climate change perspective. Freshwater Biology, 54(5), 1093–1109.
Abstract: 1. Variations in the light regime can affect the availability and quality of food for zooplankton grazers as well as their exposure to fish predation. In northern lakes light is particularly low in winter and, with increasing warming, the northern limit of some present-day plankton communities may move further north and the plankton will thus receive less winter light.
2. We followed the changes in the biomass and community structure of zooplankton and phytoplankton in a clear and a turbid shallow lake during winter (NovemberâMarch) in enclosures both with and without fish and with four different light treatments (100%, 55%, 7% and <1% of incoming light).
3. In both lakes total zooplankton biomass and chlorophyll-a were influenced by light availability and the presence of fish. Presence of fish irrespective of the light level led to low crustacean biomass, high rotifer biomass and changes in the life history of copepods. The strength of the fish effect on zooplankton biomass diminished with declining light and the effect of light was strongest in the presence of fish.
4. When fish were present, reduced light led to a shift from rotifers to calanoid copepods in the clear lake and from rotifers to cyclopoid copepods in the turbid lake. Light affected the phytoplankton biomass and, to a lesser extent, the phytoplankton community composition and size. However, the fish effect on phytoplankton was overall weak.
5. Our results from typical Danish shallow eutrophic lakes suggest that major changes in winter light conditions are needed in order to have a significant effect on the plankton community. The change in light occurring when such plankton communities move northwards in response to global warming will mostly be of modest importance for this lake type, at least for the rest of this century in an IPCC A2 scenario, while stronger effects may be observed in deep lakes.