Life cycle of Ectocarpus siliculosus. Both Ectocarpus sexual and asexual life cycles are displayed. Gametes (right side) released from WT male gametophytes . The life history of Ectocarpus fasciculatus var. refractus (Kiitz.) Ardis. from Roscoff , France, has been studied in culture. This species proved to be the sporophytic. the sexual pheromones and infection of Ectocarpus by viruses. A proposition to (the life cycle can be completed in three months) and the ease with which.

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In most species the eftocarpus threads exhibit diffuse growth. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. The cytoplasm contains many vacuoles, which are called physodes.

Life Cycle of Ectocarpus (With Diagram) | Algae

The protoplast of each compartment is metamorphosed into a single biflagellate zoospore. The zygospore germinates after days. The anterior flagellum is longer, pantonematic and directed forward while the posterior is shorter, acronematic and directed backward Fig.

Ectocarpus is word-wide in distribution particulary lifd colder seas and Polar Regions. These gametes are morphologically identical but one is less active, becomes passive after a short period and behaves as female gamete. These zoospores are haploid, they withdraw flagella and attach to the substratum by their anterior ends.

Quick Notes on Ectocarpus (With Diagram) | Algae

This stage is called clump formation Fig. These two types of zoosporangia may be produced on the same plant or on different plants. The sexual thalli of Ectocarpus are haploid. In Ectocarpus ectocarphs sporophytic and gametophytic plants are morphologically similar hence there is isomorphic alternation of generation Figs.


In Ectocarpus the sporophytic and gametophytic plants are morphologically similar hence there is isomorphic alternation of generation Figs. Each nucleus of the sporganiuin gets surrounded by protoplast segment and ultimately transforms into zoospores Fig. After sometime one male gamete fuses egg to make zygospore and other gametes detach themselves from female gamete.

Each protoplast then metamorphoses into a pear-shaped zoospore.

Anisogamy is very common. The cyfle gamete after liberation secretes a volatile sexual attractant sirenine. The former produce diploid zoospores and the latter produce haploid zoospores.

Answer Now and help others. This multicellular structure is called plurilocular sporangium. Zoospores from unilocular sporangia develop into gametophytes Fig. Reproductive Structures of Ectocarpus Algae. Plant body is filamentous, much branched and heterotrichous, having basal rhizoids and well-developed branched erect system.

The gametes are produced inside the plurilocular gametangia, developed on haploid plants. They do not fuse but develop new plant ectocarpjs. Most of the Ectocarpus species are anisogamous.

Life Cycle of Ectocarpus (With Diagram) | Algae

The gametes are liberated in water through terminal or lateral pore in gametangium. The zoospores discharge en-masse in gelatinous matrix through a terminal pore in sporangium. It repeatedly undergoes transverse divisions to form a row of cells Fig.

The single nucleus of the young unilocular sporangium divides and redivides producing 64 nuclei. Its diploid nucleus divides mitotically to make diploid Ectocarpus plant. The apical part of each filament generally terminates into hairs.

Cycld divisions are transverse and vertical in these cells to make hundreds of cubical cells arranged in transverse layers. These zoospores are produced in unilocular and plurilocular sporangia Fig.


Some cells of the prostrate filament become active and form erect filaments. The cells of the meristem cut off segments both above and below, the former add to the length of the terminal hair, while the latter give rise to branches.

The cell wall is differentiated into two layers, the inner firm layer is made of cellulose and the outer ectocarups layer contains alginic acid.

The two gametes of same gametangium or from two different gametangium of same thallus fuse to from zygospore. The formation of unilocular and plurilocular sporangia is affected by environmental conditions like temperature and salinity of water. A large number of male gametes are attracted and cluster around female gamete to make clump formation Fig. Some species like E. These diploid zoospores multiply only sporophytic plants and they do not play any role in alternation of generation.

Both haploid and diploid plants are morphogically identical Fig. The protoplast of each cubical cell in gametangium metamorphosis into single biflagellate pyriform gamete.

Life Cycle of Ectocarpus (With Diagram) | Phaeophyta

The cells are arranged in regular rows. The micro-and macrogametes after liberation fuse and form zygote, Fig. There is no reduction division during the formation of zoospore in plurilocular sporangium.

They are commonly available in both tropical and temperate seas.