Focus on aquatic technology, dedication of practical fish farming information!
Water is the environment and carrier of fish life, as the saying goes: "fish can not do without water", "if you want to raise a pond of fish, you must first raise a pool of water". The importance of water to fish farming is fully illustrated. "Fish can't do without water!" The truth is known all over the world, but the water has different waters, different waters raise the same fish, the effect is not the same! This requires us to recognize as much as possible the properties of water, especially the discrimination of "water bloom" is very important.
First, "watch the water to raise fish" and algae blooms
The quality of the water environment directly affects the growth of fish and farmed animals and the occurrence of diseases. Pond fish farming in China is very rich in dissolved organic matter and nutrient salts in water, the amount of phytoplankton is very high, the water color is strong, or the polyculture variety is improper, and sometimes there are algae masses, floating membranes, etc., that is to say, there are often blooms, simply put, the water has a very obvious color. Blooms, also known as algal blooms, are obviously known to be algae will have blooms, blooms are a common phenomenon in pond culture, excellent blooms are based on the bait effect of filter-feeding fish, for the breeding ponds of filter-feeding fish (such as silver carp), any algae bloom may lead to deterioration of water quality, which is harmful.
It is generally believed that there are many types of algae that produce blooms, the cells of golden algae, yellow algae, diatoms and dinoflagellates are brown or brownish green, and their blooms are also close to the above colors, green algae and naked algae cells are green, their blooms are also close to green, common cyanobacterial blooms look like a layer of green paint on the surface of the water, the cells of cyanobacteria are dark green or dark blue, and their blooms are also close to dark green or blue-green. Cryptoalgae blooms are like a cloud of black water, and there are other species, each with different symptoms.
(Excellent water body)
Second, the complexity of algal blooms
Although the same phylum algae have their commonalities in pigment composition, there are also special cases, such as cyanobacteria species are generally blue-green or gray-green, and some species (Monsophilus, mud brown mat algae, etc.) because of the content of more melasma (caribrin and lutein) and red pigment (phycotex) and make the cells appear melasma, reddish brown and purple and other colors; naked algae are usually green, but there is a large amount of heme in the blood red naked algae and cells to make the water reddish brown; some algae have cyst shells, so that the water is shelled, the color of the shell and nail.
In addition, the pigment composition of the same species can also be changed when the living conditions change, especially cyanobacteria and green algae, when the population growth reaches the end of the exponential growth period, often due to insufficient nutrients (nitrogen, phosphorus, carbon or trace elements) or other reasons to cause the cells to appear cyanobacteria and green algae "aging" phenomenon, when the chlorophyll decreases and the amount of carotene and lutein increases, so that the algae body yellow or brown.
(Cyanobacteria "aging")
The phenomenon of changing the color of various algae to adapt to light conditions is more widespread. It has been observed that the blooms of golden algae, diatoms, cryptoalgae and dinoflagellates are almost all brown, brownish green or brownish blue, while the blooms of cyanobacteria, green algae and naked algae are not only green and blue-green, especially cyanobacteria may occupy a larger number in almost all kinds of water colors. It can be seen that it is difficult to accurately determine the composition of plankton simply from the color of water, and the quality of water quality is not only a matter of species composition.
3. The 15 basic types of water blooms
China's fish farmers have accumulated valuable experience in long-term production practice of "watching water and raising fish", and in production, they generally judge the excellent water quality by observing the water color and the activity status of fish, and the essence is to observe the color, appearance and changes of the water bloom. Regarding water color and phytoplankton species and their relationships, they can be divided into 15 basic types according to the dominant species.
(1) Cryptoalgae blooms.
Cryptoalgae bloom is a common bloom in pond fish farming in China, and its frequency of occurrence can reach 80% to 100% in fertilizer water, and the sub-dominant species are often called small ring algae, cyanobacterial algae and some species of chlorella. The water color is brown, reddish brown, brownish green and brownish blue. Available all year round.
(2) Knee-oral algae blooms.
Knee-mouth algae blooms, the most common blooms after summer fertilization in fish ponds, occur nearly 60% more frequently during the growth period. The dominant species are oblate knee-mouth algae, the sub-dominant species are cryptoflagellum and psilocyces, and sometimes there are more chlorella, aquamarine or brownish green.
(3) Naked dinoflagellate blooms, dinoflagellate blooms.
Psilocybinous algae blooms, which are caused by large numbers of blue-green dinoflagellates, are more common in fertile water and occur more often in summer and autumn. In summer, it coexists for a long time with oblate knee-mouth algae. Aqua brownish green, brownish blue or iron gray.
Dinoflagellate blooms, the emergence of "red water" in the pond is a common water quality problem encountered by farmers, of which dinoflagellates are considered to be one of the reasons for the redness of the cultured water body.
(4) Horn algae blooms.
Horn algae blooms, sometimes seen in carp ponds, are dominant species of flying swallow horn algae, the water color is uneven yellow-brown, and thick brown patches formed by flocks of flying swallow algae can be seen.
(5) Fibrillator or mat algae blooms.
Blooms formed by certain species of the genus Algae or Algae. The aqua color is blue-green to gray-green, but individual species can cause a special water color, such as the bloom of the Eropus algae is often yellowish brown, the reddish trilled algae bloom is red, and the mud brown mat algae bloom is reddish brown. It occurs mostly in the summer.
(This is a trembling algae, and in the microscope, he is vibrating all the time, just like trembling)
(6) Ichthyosaurus or ichthyophytes blooms.
Blooms caused by spirulina or other ichthymatous algae species and ichthymatoids. The dominant species is extremely prominent, accounting for more than 95% of the total biomass, aqua blue-green or dark green, visible emerald green yarn or blue-green floating film. Appears in summer.
(Fishy algae, the big cell in the middle is an alien cell, used for nitrogen fixation)
(Spirulina, spirulina is a spiral-shaped fishy algae, and larger alien cells can also be seen in the figure)
(7) Microcystic algae blooms.
Microcystis blooms, the dominant species are microcystis aeruginosa and powdery microcystis, aqua blue-green, dark green or yellow-green whitish. Microcystis aeruginosa often has a blue-green or yellow-green floating membrane on the surface of the water, which occurs mainly in summer.
(What microcysticles look like in a microscope)
(Microcystis blooms, the water surface is like sprinkling green paint)
(Microscopic microcystis aeruginosa)
(8) Tip-headed algae blooms.
Pointed algae blooms, blue-green or yellow-green in water, often with floating membranes on the water surface, appear in summer or early autumn.
(9) Micro-cyanobacteria blooms.
Blooms caused by some very miniature species of Cyanophylla. Dominant species are often cyanophyllum, stick algae, cyanofibrous algae, sticky chlorella and phylum, etc., with aqua dark green, blue-green, brownish green, brown and yellow-brown.
(10) Clugae blooms.
Blooms of the order Chlorella, usually formed by Chlamydomonas, Tetraflagellum, Hollow Bulbophyllum and Chlorella, etc., are also abundant in cryptogagae and other flagella species. The water color is green, and the water surface often has a green floating film.
(11) Chlorella blooms.
Chlorella blooms, usually composed of chlorella, gravis, tetragonal algae, cruciferous algae, chlorella and hollow algae, etc. blooms, yin algae and other flagella and small ring algae account for a certain amount, water color green or yellow-green, transparency is larger, easy to appear in shallow water and often fertilized fish ponds.
(12) Naked algae blooms.
Naked algae blooms, mainly formed by red naked algae, usually in large numbers of cryptoalgae and other flagellar algae. The aqua green is red, green or reddish brown, and the water surface usually has a red floating film.
(Naked algae are often very green in water, because there is a lot of oxygen production, and it will be hit with a lot of foam by the aerator)
(13) Cystic bare algae blooms.
Cyst nudibras blooms, usually formed by spiny sacs of naked algae and rotational sacs of naked algae, etc., water surface soot or reddish brown.
(14) Diatom blooms.
Diatom blooms, mainly formed by small ring algae, needle algae, boat-shaped algae and rhomboid algae. Cryptococcus and chlorella chlorococcus are also usually found in larger numbers. Aqua brown with greater transparency. Mostly appear in the spring and autumn.
(15) Golden algae blooms.
Golden algae blooms, often formed by brown flagella and single whip golden algae, usually more diatoms and cryptoalgae. The water color is golden brown with greater transparency. Occurs mainly in early spring.
Regardless of the water color shown in this article, because the presence of algae in the water body is not independent of any kind of algae, there are many kinds of algae coexisting in one water, and there are many subdivisions under one algae order, sometimes even the same algae, the water color displayed under different conditions is also different. Farmers can judge the algal phase of the cultivated water body by the water color and microscopic microscopy confirmation, which is much more accurate than observing the water color. Therefore, if you want to confirm a certain bloom phenomenon, you must rely on the algae seen under the microscope. The above list of figures is for reference only, and it may be difficult for rabbits to make mistakes!
4. Beneficial algae and harmful algae
There are many types of algae, usually some algae are beneficial to aquaculture, and some algae are harmful to aquaculture, but beneficial algae and harmful algae are not absolute, but relative. For example, chlorella, phylloxera and oocyst algae in green algae are all algae that are currently cultivated in large quantities, and sponge and bristle algae are also algae of green algae, but it belongs to the moss class, which is harmful to aquaculture. Another example is cyanobacteria, everyone talks about cyanobacteria algae are very panicked, afraid that it will multiply and cause harm, but the algae in cyanobacteria are not all harmful species, and some algae are beneficial algae, such as spirulina.
In addition, in our fishery production, we must focus on the identification of cyanobacteria, naked algae, golden algae, green algae, diatoms, etc. with prominent and common characteristics and blooms. In production practice, the various response plans and measures taken by farmers to water blooms sometimes do not necessarily have to be treated, and sometimes they may also be the performance of living water "red and night green". In addition, when the weather continues to be hot, although there is a temporary occurrence of bloom outbreaks, which is the inevitable force of climate change on water quality, as long as the fish are not abnormal, the aerator can be opened at night; if the silver carp is not put or less, then add some silver carp seedlings. In the hot season, the water quality has a bloom outbreak, as long as it does not continue to deteriorate, it is normal, the temperature can return to normal, and it is of course better to have additional water changes and water additions. Under normal circumstances, in principle, there will be no deterioration of water quality, such as changing more water, opening more aerators, and applying corresponding effective bacteria and algae. In reality, a person with a lot of experience and level of farming, his fish pond rarely has water quality deterioration, and most of the time his farming is profitable! Worth paying attention to!
See also:
A brief analysis of the causes and treatment methods of cyanobacterial outbreaks: it is annoying and cannot be avoided and lingering
From a "bad water quality" phenomenon to analyze the "open aerator is king!" "
Controlling the "breeding" of cyanobacteria is far more important than killing the "outbreak" of cyanobacterial blooms
"Magic elixir" can not be replaced: the regular opening aerator is a good water detoxification and water transfer measures
Common algae and their characteristics in aquaculture
Two kinds of algae that seem to be similar: it is easy to confuse naked algae with cyanobacteria! Tell us about the characteristics of naked algae
Complex algae-water color relationship: six typical water colors and their dominant algae
Cyanobacteria's past and present lives: precautions are far more important than prevention and control! Ideas and concepts are more important
(Comprehensive Editor: Southwest Fisheries Network)
Aquatic practitioners, conspire for the prosperity of the fishery! For more wonderful content, please pay attention to the headline number @ Fisherman Liu Wenjun, if this article is original, please indicate the source, if you have different opinions or content supplements, please share private messages or messages or comments! #Aquaculture##Farming##Farming##Feed##污水处理 #