What are the main characteristics of a dense outbreak of fish fleas (water fleas)?
What are the characteristics of a dense outbreak of fish fleas?
Fish fleas grow in large numbers in nutrient-rich ponds and ditches near city suburbs, villages, towns and markets. When spring arrives, once the water temperature rises above 10°C, fish fleas begin to reproduce and increase; when the water temperature rises to 18°C, fish fleas multiply in large numbers and grow rapidly. From spring to summer, especially in midsummer, when environmental conditions are good, fish fleas reproduce quickly. In certain ditches and ponds, when red worms (bloodworms) break out in abundance they form huge populations, and at dawn a dense red layer can be seen on the water surface. By late autumn they gradually decrease. The rise and fall in fish flea numbers is closely related to factors such as season, water temperature, light and the content of nutrients in the water, and different species of fish fleas have different requirements for these conditions. Therefore, in different regions and different seasons, different species increase and decline. Experienced people can correctly grasp and apply these natural laws, choosing the appropriate place and time to catch them, thereby obtaining large quantities of fish fleas.
The seasonal pattern of fish flea reproduction and growth is particularly obvious, and growth is also extremely fast. In general, in early spring when temperatures are still low, mainly copepods grow in the water body; by late spring when temperatures rise again, cladocerans begin to multiply in large numbers; after entering summer, water temperature rises relatively quickly, and both rotifers and cladocerans reproduce rapidly, making them easier to catch at this time. After summer rain showers, scenes of dense fish flea outbreaks can often be seen in water-filled pits in wasteland by rural roadsides and in small water-filled pits by urban roadsides. One can go to ponds, lakes and other places to catch large quantities of fish fleas, which after sun-drying and processing can be sold as a commodity, used as bait for home aquarium fish keeping, and also partly exported for sale abroad. In autumn, with continuous autumn rain and temperatures gradually falling, the number of rotifers decreases and production declines; when winter temperatures continue to drop, cladocerans further decrease, and only a small amount of copepods can be caught.
Besides the seasonal pattern of numerical change, fish fleas also have a pattern of daily vertical migration. From night until before dawn, they move from the deep water layer toward the surface layer, which is very obvious in the water pits and ditches where fish fleas multiply and grow in large numbers. By dawn, they have all floated up to the upper and surface layers. Within 1-2 hours after sunrise, they move down again toward the lower water layers, returning to the deep layer. If the number of fish fleas is relatively small, this pattern is not obvious. According to analysis, the main reason for this daily rise and fall, sinking by day and floating by night, is insufficient dissolved oxygen in the water body. The huge populations of red worms need to consume large amounts of oxygen, and they crowd together and are difficult to disperse, so at dawn the dissolved oxygen in the lower water layer drops to its lowest value. Therefore, in the peak red worm season from June to August, red worms remain densely concentrated in the surface water layer for several hours after sunrise. As long as one understands this living habit of red worms - rising at sunset and sinking at sunrise - and goes to ponds, lakes and other places to catch them around dawn, one can capture large quantities of fish fleas.
The seasonal pattern of fish flea reproduction and growth is particularly obvious, and growth is also extremely fast. In general, in early spring when temperatures are still low, mainly copepods grow in the water body; by late spring when temperatures rise again, cladocerans begin to multiply in large numbers; after entering summer, water temperature rises relatively quickly, and both rotifers and cladocerans reproduce rapidly, making them easier to catch at this time. After summer rain showers, scenes of dense fish flea outbreaks can often be seen in water-filled pits in wasteland by rural roadsides and in small water-filled pits by urban roadsides. One can go to ponds, lakes and other places to catch large quantities of fish fleas, which after sun-drying and processing can be sold as a commodity, used as bait for home aquarium fish keeping, and also partly exported for sale abroad. In autumn, with continuous autumn rain and temperatures gradually falling, the number of rotifers decreases and production declines; when winter temperatures continue to drop, cladocerans further decrease, and only a small amount of copepods can be caught.
Besides the seasonal pattern of numerical change, fish fleas also have a pattern of daily vertical migration. From night until before dawn, they move from the deep water layer toward the surface layer, which is very obvious in the water pits and ditches where fish fleas multiply and grow in large numbers. By dawn, they have all floated up to the upper and surface layers. Within 1-2 hours after sunrise, they move down again toward the lower water layers, returning to the deep layer. If the number of fish fleas is relatively small, this pattern is not obvious. According to analysis, the main reason for this daily rise and fall, sinking by day and floating by night, is insufficient dissolved oxygen in the water body. The huge populations of red worms need to consume large amounts of oxygen, and they crowd together and are difficult to disperse, so at dawn the dissolved oxygen in the lower water layer drops to its lowest value. Therefore, in the peak red worm season from June to August, red worms remain densely concentrated in the surface water layer for several hours after sunrise. As long as one understands this living habit of red worms - rising at sunset and sinking at sunrise - and goes to ponds, lakes and other places to catch them around dawn, one can capture large quantities of fish fleas.