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An order of algae in the division Chlorophyta in which the thalli are macroscopic, attached tubes or sheets.



an order of green algae. The thallus is lamellate (consisting of one or two layers of cells), tubular or saclike (consisting of a single layer of cells), or filamentous (consisting of two rows of cells). The cells are mononuclear, and the chloroplasts are lamellate and have pyrenoids. Vegetative reproduction is achieved with parts of the thallus; asexual reproduction is by means of zoospores having two or four flagella. The sexual process is iso-gamy or heterogamy. The zygote appears without a resting period, and meiosis occurs with the formation of the zoospores. The sporophyte and gametophyte have the same structure, or one may be multicellular or unicellular but considerably smaller than the other. Sometimes one of the forms is omitted from the developmental cycle.

The algae grow in seas and, less commonly, in brackish and fresh waters. Some species of the genera Viva, Monostroma, and Enteromorpha are used as food. Monostroma are cultivated in Japan.

The Russian common name for the order Ulvales is also used to designate a family of that order, Ulvaceae, which comprises the above-mentioned genera.


See references underALGAE.
References in periodicals archive ?
Los ordenes que presentaron mayor riqueza de especies fueron Ulvales y Cladophorales con ocho y siete especies respectivamente.
Mexico Afinidad # de Biogeografica Catalogo DIVISION CHLOROPHYTA CLASE ULVOPHYCEAE ORDEN ULVALES Familia Ulvaceae Enteromorpha intestinalis (Linnaeus) Link Cosmopolita 2130 Ulva lactuca Linnaeus Cosmopolita 2131 ORDEN CLADOPHORALES Familia Cladophoraceae Chaetomorpha linum (Muller) Kutzing Templado 2132 Cladophora columbiana Collins Templado 2133 Cladophora microcladioides Collins Templado 2134 ORDEN SIPHONOCLADALES Familia Siphonocladaceae Dictyosphaeria cavernosa (Forsskal) Borgesen Tropical 2135 ORDEN DASYCLADALES Familia Dasycladaceae Acetabularia calyculus Quoy & Gainard Tropical 2136 Neomeris annulata Dickie Tropical 2137 ORDEN CAULERPALES Familia Caulerpaceae Caulerpa racemosa (Forsskal) J.
Ecological Species Abundance zone Division Chlorophyta Class Chlorophyceae Order Ulvales Family Ulvellaceae Ulvella lens H.