Difference Between Algae and Moss

Algae and moss are two types of organisms that are often studied in biology. While they are both classified as non-vascular plants, there are several significant differences between the two.

What are Algae?

Algae are unicellular or multicellular organisms that belong to the kingdom Protista. They are found in aquatic environments such as oceans, lakes, and ponds. Some species of algae can also be found in soil and on moist surfaces such as rocks and trees. Algae can be classified into three main groups based on their pigmentation: red algae, green algae, and brown algae. Red algae are found in deep waters and are known for their red coloration, while green algae are found in shallow waters and are green in color. Brown algae are found in colder waters and are known for their brown coloration.

Algae are subdivided to −

• Green algae − The predominant pigment in their cells is chlorophyll (Examples − Ulva, Spirogyra, Chlorella)

• Red algae − In their chloroplasts predominate red pigments (Examples − Lemanea, Audouinella, Coralline)

• Brown algae − In their chloroplasts predominate brown and yellow-brown pigments (examples − Laminaria, Sargassum, Ectocarpus)

• Diatoms − The cell wall is made of silicon dioxide. The cell cytoplasm contains yellowish-brown pigments (examples − Navicula, Melosira, Cyclotella)

The thallus of the algae can be filamentous, plate-like, branched, etc. Some brown algae reach up to 30-60 m in length.

Algae are a very ancient group of marine and freshwater plants. Some have adapted to live in humid soils, tree bark, wet rocks, etc. They can be floating or attached to the bottom of the water basins by special cells.

Different groups of algae inhabit different depths in the water basins. Green algae live in shallow waters. Brown algae are spread up to 40-50 m depth. Red algae can reach up to 100 m depth.

Algae exhibit a wide range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction.

Algae are actively involved in the circle of substances in the nature. They synthesize nutrients and enrich the water bodies with oxygen. Algae are an important part of the water ecosystems and provide oxygen and food for the aquatic animals.

What is Moss?

Mosses are a group of higher plants characterized by the absence of special tissues designed to conduct water. Unlike the other higher plants, mosses do not have roots, but rhizoids. The group is paraphyletic.

Mosses are relatively small plants (1 to 10-20 cm), very diverse in morphological terms. Most likely they have evolved from the green algae. They have a similar pigment complex and a close morphology of the gametophyte.

• There are more than 12000 species of mosses. The science that studies mosses is called bryology.

• The reproduction of mosses is asexual and sexual. The sexual reproduction requires water.

• The mosses are multicellular, perennial or annual plants. Perennial mosses are evergreen.

• Most mosses are terrestrial. There are also water mosses, which have adapted to this habitat secondarily.

Mosses are divided into −

• Hornworts − One of the oldest groups of existing today terrestrial plants. The cells in most of the species contain only one chloroplast, which is common for algae, but not for the higher plants. They attach to the ground with simple rhizoids.

• Bryophytes − Usually 1-10 cm high, most often growing in dense tufts in humid places. They have clearly distinct leaf and stem, and multicellular rhizoids.

• Liverworts − Small irregular tile-like plants covering large areas of the ground, rocks, trees, and other surfaces.

• Peat mosses − Mainly found in peat bogs. Most species are colored in red or brown. The stems grow in piles and carry a group and branches. The stem contains one or two layers of dead cells that transport water through the capillary path.

Examples of mosses are Notothylas, Megaceros, Bryum, Lunularia, Sphagnum, etc.

The peat is used for fertilizing and growing of plants, for heating, and for the treatment of rheumatoid diseases.

Differences: Algae and Moss

One of the most significant differences between algae and moss is their cell structure. Algae are unicellular or multicellular organisms that have a simple cell structure without roots, stems, or leaves. They do not have a well-defined nucleus and lack a true cell wall. In contrast, mosses have a more complex cell structure with a nucleus, chloroplasts, and a cell wall made of cellulose. Mosses also have a stem-like structure called a stipe, which is covered with small leaves called phyllids

Another major difference between algae and moss is their reproductive strategies. Algae reproduce asexually through cell division or sexually through the fusion of gametes. Some species of algae also have complex life cycles that involve both sexual and asexual reproduction. Mosses, on the other hand, reproduce sexually by producing male and female gametes that fuse to form a zygote. The zygote then grows into a sporophyte, which produces spores that are dispersed and grow into new moss plants.

In terms of ecological significance, algae and moss play important roles in their respective ecosystems. Algae are the primary producers in aquatic environments and are an important food source for many aquatic organisms. They also play a significant role in the global carbon cycle by absorbing carbon dioxide from the atmosphere through photosynthesis. Mosses, on the other hand, are important in maintaining soil structure and preventing erosion. They also provide habitat and food for a variety of organisms such as insects and small mammals.

The following table highlights the major differences between Algae and Moss −

Characteristics	Algae	Moss
Definition	Algae are a diverse polyphyletic group of lower thallus plants.	Mosses are a diverse polyphyletic group of higher plants characterized by the absence of special tissues designed to conduct water.
Number of species	There are more than 30000 species of algae.	There are more than 12000 species of mosses.
Science	The science, which studies algae, is called algology.	The science, which studies mosses, is called bryology.
Structure	Algae include unicellular, multicellular, and colonial organisms.	All mosses are multicellular organisms.
Divisions	Algae are subdivided into diatoms, green, red, and brown algae.	Mosses are divided into hornworts, bryophytes, liverworts, and peat mosses.
Size	From several micrometers (unicellular algae) to several tens of meters (some brown algae).	From less than 1 cm to 10-20 cm.
Habitat	Algae are mainly marine and freshwater plants. Some species have adapted to live in humid soils, tree bark, wet rocks, etc.	Most mosses are mainly terrestrial. Some species have adapted to live in the water.

Conclusion

In conclusion, algae and moss are two types of non-vascular plants that have several significant differences in their cell structure, reproductive strategies, and ecological roles. While algae are unicellular or multicellular organisms found in aquatic environments, mosses are small, non-vascular plants found in damp or shady environments.

Despite these differences, both algae and moss are essential components of their respective ecosystems and play important roles in the global carbon cycle.