Phytoplankton survey and identification experiments
Phytoplankton survey and identification experiments
Source: Experiments in Botany
Operation method
basic program
Principle
Phytoplankton is mainly composed of a number of species of algae, whose groups are mainly cyanobacteria, green algae, nudibranchs, golden algae, yellow algae, diatoms and methanobacteria seven categories. Phytoplankton is generally small, difficult to see with the naked eye, need to use a microscope to observe its fine structure. Among them there are unicellular bodies, groups, and some are filamentous (mostly unbranched). Most of the dynamic features in the water column, such as clarity, nutrient status, zooplankton and fish production, depend to a large extent on phytoplankton. Therefore, the investigation and identification of phytoplankton is closely related to fishery production and environmental protection.
Materials and Instruments
Algae Move 1 Phytoplankton survey and sampling (1) Survey and sampling gear: Plankton net: including qualitative net and quantitative net. The qualitative net is used for qualitative collection of plankton within 50cm of the surface layer and consists of three parts: a copper ring, a net bag and a net head; the quantitative net is used for quantitative collection of plankton within 50cm of the surface layer, and the net is slightly longer and has an additional set at the front end to minimize the loss of plankton when trailing the net. The net is slightly longer and has an additional sleeve at the front to minimize the loss of plankton when the net is being towed. ② Water collector: It is used to collect plankton in the water layer below 50cm. ③ Sedimentation device: used to sediment the fixed water samples, which can be replaced by 1000cm wide-mouth bottles or liquid-dispersing buckets. ④ Fixing solution: used to fix the plankton in the water sample, commonly used formalin solution and Lugol's solution. (2) Phytoplankton qualitative sampling: when collecting phytoplankton, 25# qualitative net can be used to collect the sample point on the horizontal towing, 'pole reservoirs and small and medium-sized lakes to collect, the qualitative net can be tied to the boat to slow towing I0-20m; n. If in small water bodies such as puddles and ponds, the qualitative net can be used to collect phytoplankton samples. Such as in the pit ponds and other small bodies of water, the net can be tied to the 2m long bamboo poles, so that the mouth of the net below the surface of the water at a depth of about 50cm, to do the "∞" shape repeatedly towed 3-5m;n. Then the net lifted and shaken, to be filtered out of the water, open the head of the net, poured into the labeled specimen bottles, plus the fixation of the liquid fixed. (3) Quantitative phytoplankton survey: At each sample point, stratified sampling was done with a water collector according to the depth of water. Each time the water sample is taken 1000mL, add 15ml of Ruggier's solution for fixation, and keep it for quantitative analysis indoors. The fixed water samples were put into a 1000mL precipitator for 24h, the upper layer of clear liquid was sucked out, and the remaining 20mL of sediment was transferred to a 30ml batch bottle, the precipitator was rinsed with the supernatant and transferred to a fixing bottle to be fixed to 30mL, if the specimen needs to be stored for a long time, formalin should be added to 3-4mL. A certain volume of sample was sucked up by a micro sampler, mounted on a piece, and counted under a microscope for phytoplankton counting. The phytoplankton were counted under microscope and the number of phytoplankton per liter of water was deduced. 2 Identification of phytoplankton Fresh or fixed water samples are left under the microscope for identification of genera and species and listing of phytoplankton in the site under investigation. Observation and identification of various phytoplankton is a very difficult work, microscope observed an algal plant, first of all, according to its morphology, structure and habits and other characteristics of its classification into the major phyla, and then can refer to the freshwater phytoplankton atlas, species identification: (1) Cyanobacteria: there are about 150 genera and 1500 species. The phytoplankton is usually blue or blue-green in color, with different body types such as unicellular body, group and filamentous body, and the cells constituting the phytoplankton are prokaryotic cells. It is widely distributed and is an important part of freshwater phytoplankton. Living in freshwater planktonic cyanobacteria, in the warm season, often reproduced in large quantities, gathered on the surface of the water to form a "water bloom". (2) Naked Algae: there are about 40 genera, more than 800 kinds of, in addition to the genus Gelidium, are no cell wall, have flagellum, can swim freely single-celled algae. Mainly distributed in freshwater, especially in organic matter-rich small puddles and small puddles of the most common, the camp planktonic life. This family of plants like strong light and high water temperature, in the warm season often reproduce in large quantities so that the water is green, and floating on the surface of the water to form a dark gray or yellow-green water. (3) Green Algae: It is the largest phylum of algal plants, with about 350 genera and 5000-8000 species. The plant body is usually grass-green in color with various forms, such as unicellular body, group rest, filamentous body and leaf-shaped body. Most of the species are distributed in freshwater, rivers, lakes, streams, ponds, ditches, and even puddles. Many unicellular, group and filamentous species float in the water and live a planktonic life, which is an important part of freshwater phytoplankton. Commonly found in freshwater are the order of Aphanizomenon, Tetrasporangium, Chlorophyceae, and Spliceophyceae, etc., of which the vast majority of species live a planktonic life. (4) Golden Algae: There are about 70 genera and 250 species, and the cypress objects are mostly unicellular bodies and groups, with flagella, and they live in planktonic life. The plant body of this phylum is often golden brown. Gold algae are mainly distributed in freshwater, planktonic life, most like to live in soft water and greater transparency of the water in the spring and fall seasons, mostly in the lower water temperature, the number of summer is most obviously reduced. Most of the species that can move in this phylum do not have cell walls, and it is not easy to preserve the collected specimens, so it is usually necessary to use live specimens for species identification. (5) Yellow Algae: There are about 75 genera and more than 370 species, the plant body is usually yellowish-green, and most of the species are non-motile unicellular bodies or groups. Most of the species are non-motile unicellular bodies or groups. The plants in this phylum are mainly freshwater producers and prefer to live in semi-fluid and cleaner soft water. (6) Diatoms: There are about 155 genera and more than 5400 species of diatoms with unicellular bodies or groups, and the groups are filamentous, banded, stellate and radial. The cell walls of the plants in this phylum contain silica, by the upper and lower shells into the freshwater diatoms to the plume diatoms in the order of the largest number of species, and it is common to have a number of planktonic species. Diatoms usually like low temperatures, in the extremely light and low temperatures in the spring and fall, often can be reproduced in large numbers. (7) Phylum Chlamydomonas: There are 135 genera and more than 1,000 species. Most of the plant body can swim for the unicellular body, slightly spherical oval, body color is usually yellowish green or golden brown wood door of freshwater planktonic species are from the Cryptophyta, mostly living in the organic matter, hardness of ponds, small lakes and reservoirs, warm and ambiguous season is especially common. For more product details, please visit Aladdin Scientific website.
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