The above is the common algae we encounter in the aquaculture process, especially in the hot weather of this season, if you are not careful, you will encounter the phenomenon of cyanobacterial blooms of algae, which will bring huge losses to farmers.
The following fisheries research agency brings you a detailed explanation of algae by consulting the materials and learning the relevant expert explanation videos, hoping to help the majority of farmers.
1. Definition and characteristics of algae
First of all, the definition of algae: algae is a group of individuals small, with chlorophyll, camp self-nourishing life, no real roots, stems, leaves differentiation, in the single cell spores or zygotes for reproduction of low-grade plants.
Algae characteristics:
Individual algae are very small, have simple morphological structure (can only be observed under the microscope) and have pigments (chlorophyll a);
Can absorb light energy and nutrient salts for photosynthesis to produce organic matter, there is no real root, stem, leaf differentiation, reproductive organs are simple, single-cell spores or zygotes, do not flower and bear fruit
Speaking of algae, it is necessary to mention the photosynthesis of algae in water bodies:
Photoenergy is the biochemical process of plants, algae and certain bacteria, under the illumination of visible light, using photosynthetic pigments to convert carbon dioxide (or hydrogen sulfide) and water into organic matter, and releasing oxygen (or hydrogen).
Through this reaction formula, we can see that algae can use carbon dioxide and water through chlorophyll in their own body to synthesize organic matter for aquaculture animals to grow.
2. Ecological taxa of algae
1 Planktonic algae:
Camp pelagic life, when the environmental conditions are suitable, rich in nutrients, algae multiply in large quantities, so that the water shows a bright color. Cyanobacteria is one of them.
2. Benthic algae
Standing algae refers to the surface of various substrates (submerged plants, stakes, stones, etc.) that grow in submerged water and hold a solid life.
Can be used as bait for omnivorous and scraped fish
3. Flowing algae
Composed of benthic and planktonic algae that live and reproduce in rapids;
Together with bacteria and micro-animals, a clay layer is formed, which has a huge adsorption force, can adsorb organic matter in polluted water bodies and mineralize them by biota, playing an important role in the purification process of polluted water bodies.
Third, the division of algae gates
According to the classification system of "Phytopodidae": 11 algae can be divided, 8 of which are freshwater algae and the rest are marine algae.
Isn't it a little panicky to see so many algae? However, through microscopic observation, the appearance shape of algae generally has three structures: single cells, populations, and filaments.
Internal structure of algal cells: cell wall, protoplasts: nucleus, cytoplasm (pigment bodies, protein nuclei, assimilation products, etc.).
1) There are cell wall species
Most cell walls are smooth, with a few walls with patterns, spines, and spinous processes.
Among them, the phylum green algae: composed of cellulose and pectin (pectin); the main component of the phylum diatom: SiO2 .nH2O, with patterns, protrusions or spines.
2) Species without cell wall
The body is completely bare, and the cells can be deformed, such as naked algae, cryptoalgae forming cyst shells or periplasts
Then there is the pigment component unique to algae, which can be divided into 4 categories: chlorophyll, carotene, lutein, and algal cholelin.
Each phylum algae has chlorophyll a and β- carotene; chlorophyll b, chlorophyll c, chlorophyll d, algal cholelin is endemic to some algal phylums.
Pigment is more important because the carrier of pigment, a pigment-containing protein, is the place where algae photosynthesize. The shapes are cup-shaped, disc-shaped, star-shaped, flaky, plate-like and spiral-like.
Fourth, the reproduction method of algae
(1) Vegetative reproduction can be divided into: cell division: single-cell algae; group fragmentation: population type; algal filament rupture: filamentous body.
(2) Asexual reproduction: Reproduction by producing different types of spores.
The mother cell that produces the spores is called the sporangia, and the spores are asexual and do not need to be combined, and a spore can grow into a new individual. Hence the name spore reproduction.
(3) Sexual reproduction can be divided into: homosexuality, heterosexuality, egg matching, and joint reproduction, of which the joint reproduction is unique to the green algae phylum: such as water wool.
The above is the classification of algae that will appear in the water body in the aquaculture process, among which the cyanobacteria that we are most concerned about are the most likely to erupt in this season due to their high temperature and good light characteristics.
And cyanobacteria like high pH and relatively static water environment, because of its own structure like low nitrogen and high phosphorus, so according to these characteristics will be targeted for our control of cyanobacteria.
Since cyanobacteria are more special, tomorrow will write a special lecture on cyanobacteria to provide some help for the majority of farmers in dealing with cyanobacteria.