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Seaweeds

Characteristics

  • All seaweeds are eukaryotic.

  • They can be unicellular and pluricellular.

  • Seaweeds have plastids, which contain chlorophyll and other pigments. Thus, algae are photosynthesizing autotrophs. Seaweeds inhabit environments that have moisture and light. This includes the moist soil and the aquatic environment.

  • Algae Aquatic algae can occupy the surface, forming phytoplankton, as do many Chlorophyceae, diatoms, and dinoflagellates. Certain algae are attached to the bed of the aquatic environment, forming part of the benthic. Certain Chlorophyceae, Phaeophyceae, and Rhodophyceae are benthic algae.

  • Seaweeds have several modes of reproduction. However, many unicellular algae reproduce asexually by bipartition. Through mitosis, the valves separate, and a smaller valve is always produced, which fits into the larger one. Thus, there is a reduction in size over a few generations. Subsequently, sexual reproduction occurs, generating individuals with the largest possible size for the species.

  • A peculiar case is the diatoms, which have a carapace made of two parts (called valves), a larger and a smaller one.

Variety of seaweeds

  • Chlorophyceae: these are the green seaweeds. Most species live in freshwater, but there are marine and moist soil representatives. They are considered the group closest to plants. And they share with them the form of glucose reserve: starch molecules. They include Ulva sp.; Volvox sp.; and Acetabularia sp.

  • Euglenophyceae: they are also known as euglenoid algae. The euglena is its best-known representative. These organisms are photosynthesizing and store glucose in the form of carbohydrates. When placed in places without light, they begin to consume organic matter from the environment, behaving as heterotrophs. They have a structure called the ocelli, which perceive the environmental luminosity.

  • Phaeophyceae: these are brown algae; they have the largest size of all algae.

  • Rhodophyceae: these are the red seaweeds. There are several species of food interest, and some are producers of agar, a substance used in the food industry to make culture media for bacteria. It has an energy reserve in the form of starch.

  • Chrysophyceae: are abundant in the phytoplankton; they are microscopic algae with a silica envelope with orifices (allowing for protection and the exchange of materials with the environment).

  • Pyrrophyceae: often called dinoflagellates are also abundant in the phytoplankton. Some species cause red tide, a phenomenon resulting from the release of toxins due to environmental stress, which can kill various marine organisms. The glucose reserve occurs in the form of starch and oil.

Importance of seaweeds

  • There are three main aspects to the importance of algae: food, industrial, and ecological.

  • Food Importance- Some seaweeds can be eaten by livestock and humans because they contain mineral nutrients, vitamins, and proteins. Among the edible algae are species of Chlorophyceae, Phaeophyceae, and Rhodophyceae.

  • Industrial importance- Seaweed represents sources of certain raw materials for industry. Agar is used in the production of food and culture media for bacteria. Alginate is extracted from certain Phaeophyceae, and it is in ice cream and various types of cosmetics.

  • Ecological importance- Seaweeds are components of the phytoplankton, the group of organisms responsible for most of the photosynthesis on the planet.

Seaweeds

Characteristics

  • All seaweeds are eukaryotic.

  • They can be unicellular and pluricellular.

  • Seaweeds have plastids, which contain chlorophyll and other pigments. Thus, algae are photosynthesizing autotrophs. Seaweeds inhabit environments that have moisture and light. This includes the moist soil and the aquatic environment.

  • Algae Aquatic algae can occupy the surface, forming phytoplankton, as do many Chlorophyceae, diatoms, and dinoflagellates. Certain algae are attached to the bed of the aquatic environment, forming part of the benthic. Certain Chlorophyceae, Phaeophyceae, and Rhodophyceae are benthic algae.

  • Seaweeds have several modes of reproduction. However, many unicellular algae reproduce asexually by bipartition. Through mitosis, the valves separate, and a smaller valve is always produced, which fits into the larger one. Thus, there is a reduction in size over a few generations. Subsequently, sexual reproduction occurs, generating individuals with the largest possible size for the species.

  • A peculiar case is the diatoms, which have a carapace made of two parts (called valves), a larger and a smaller one.

Variety of seaweeds

  • Chlorophyceae: these are the green seaweeds. Most species live in freshwater, but there are marine and moist soil representatives. They are considered the group closest to plants. And they share with them the form of glucose reserve: starch molecules. They include Ulva sp.; Volvox sp.; and Acetabularia sp.

  • Euglenophyceae: they are also known as euglenoid algae. The euglena is its best-known representative. These organisms are photosynthesizing and store glucose in the form of carbohydrates. When placed in places without light, they begin to consume organic matter from the environment, behaving as heterotrophs. They have a structure called the ocelli, which perceive the environmental luminosity.

  • Phaeophyceae: these are brown algae; they have the largest size of all algae.

  • Rhodophyceae: these are the red seaweeds. There are several species of food interest, and some are producers of agar, a substance used in the food industry to make culture media for bacteria. It has an energy reserve in the form of starch.

  • Chrysophyceae: are abundant in the phytoplankton; they are microscopic algae with a silica envelope with orifices (allowing for protection and the exchange of materials with the environment).

  • Pyrrophyceae: often called dinoflagellates are also abundant in the phytoplankton. Some species cause red tide, a phenomenon resulting from the release of toxins due to environmental stress, which can kill various marine organisms. The glucose reserve occurs in the form of starch and oil.

Importance of seaweeds

  • There are three main aspects to the importance of algae: food, industrial, and ecological.

  • Food Importance- Some seaweeds can be eaten by livestock and humans because they contain mineral nutrients, vitamins, and proteins. Among the edible algae are species of Chlorophyceae, Phaeophyceae, and Rhodophyceae.

  • Industrial importance- Seaweed represents sources of certain raw materials for industry. Agar is used in the production of food and culture media for bacteria. Alginate is extracted from certain Phaeophyceae, and it is in ice cream and various types of cosmetics.

  • Ecological importance- Seaweeds are components of the phytoplankton, the group of organisms responsible for most of the photosynthesis on the planet.