''Acinetospora crinita'' is a species of

brown alga Brown algae (singular: alga), comprising the class (biology), class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the ...

in the family

Acinetosporaceae Acinetosporaceae is a family of brown algae in the order Ectocarpales Ectocarpales is a very large order in the brown algae (class Phaeophyceae). The order includes families with pseudoparenchymatous (Splachnidiaceae) or true parenchymatou ...

. It is found in the temperate northeastern Atlantic Ocean and the Mediterranean Sea.

Description

''Acinetospora crinita'' forms slender, irregularly branched filaments some 25 to 35 µm in diameter. These consist of strands of cells, each up to three times longer than they are broad, of a pale brown or yellowish-brown colour. Each cell contains several disc-shaped

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...

s and a pyrenoid. The tips of the filaments are rounded; the filaments are often tangled with other algae forming bushy tufts which can grow to a length of several metres. This alga can be distinguished from other similar species by the branches growing perpendicularly from the filaments, and often emerging from the middle of a cell.

Distribution and habitat

''Acinetospora crinita'' occurs in the temperate northeastern Atlantic Ocean and the Mediterranean Sea. It is also considered to be part of a cosmopolitan

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

, being reported from Bermuda, the Caribbean Sea, the Pacific Ocean and elsewhere, and has been described as "enigmatic". Where it does grow, it sometimes consists of fragments of as many as thirty different species intermingled, with the different strains thriving in varying conditions and at different times of year. It forms a more or less complete covering of filamentous algae over the rock, detritus, living animals and sea grasses on the seabed in its habitat; its depth range is .

Biology

Like other brown algae, ''Acinetospora crinita'' uses

chlorophyll Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to a ...

fucoxanthin Fucoxanthin is a xanthophyll, with formula C42H58O6. It is found as an accessory pigment in the chloroplasts of brown algae and most other heterokonts, giving them a brown or olive-green color. Fucoxanthin absorbs light primarily in the blue-green ...

and other pigments to fix carbon dioxide by

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

. The reproductive system is very complex and has not been fully elucidated; the method used can vary with the region, the time of year and the population concerned. Several stages are involved and at least five reproductive structures have been identified. The

sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cy ...

(reproductive organs) are inserted perpendicularly to the filaments. The alga can also reproduce asexually by fragmentation. ''Acinetospora crinita'' and other filamentous algae grow vigorously in spring and summer, covering the seabed and tending to swamp other organisms, reducing their ability to filter feed and sometimes killing them. The algae thrive with warm weather, calm seas and high levels of nutrients in the water. They are eaten by herbivorous fish, but grow at a faster rate than they can be consumed.

References

External links

* {{Taxonbar, from=Q29533024 Ectocarpales