Dictyosphaeria
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| Dictyosphaeria | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Division: | Chlorophyta |
| Class: | Ulvophyceae |
| Order: | Cladophorales |
| Family: | Siphonocladaceae |
| Genus: | Dictyosphaeria Decaisne |
Dictyosphaeria is a genus of green algae (class Ulvophyceae) in the family Siphonocladaceae.[1]
The genus Dictyosphaeria belongs to the order of Cladophorales and family Siphonocladaceae. It comprises a total of 13 taxonomically recognized species.[2]
Below is a list of taxonomically accepted species from the genus Dictyosphearia:
- Dictyosphaeria australis Setchell
- Dictyosphaeria cavernosa (Forsskål) Børgesen
- Dictyosphaeria enteromorpha Montagne & Millardet
- Dictyosphaeria intermedia Weber Bosse
- Dictyosphaeria mutica Yamada
- Dictyosphaeria ocellata (M.Howe) Olsen-Stojkovich
- Dictyosphaeria sericea Harvey
- Dictyosphaeria spinifera C.K.Tseng & C.F.Chang
- Dictyosphaeria ulvacea Kützing
- Dictyosphaeria valonioides Zanardini
- Dictyosphaeria versluysii Weber Bosse
General morphological description
Thalli
The thalli are composed of visibly hollow hexagonal or polygonal cells; and are monostromatic or polystromatic depending on species. They can be solid or button-shaped at around 1–5 cm; and spherical and club-shaped at 1 cm or more. The size of each cells are around 300 - 500 μm in diameter. Complex rhizoidal system is absent, however, basal cells are firmly attached to the substrate.[3]
The coloration of the macroalgae varies from grass green to bluish.[4]
Cells
Cells are visible to the naked eye. They are minutely determinate, simple or furcate, and tenacular[check spelling] that are structurally cushioned together. Occasionally, tenacular cells may also function as adventitious rhizoids.
Cells are multinucleated and have numerous discoid chloroplasts. Chloroplasts bear single pyrenoid surrounded by starch sheath and divided to two or more portions by traversing thylakoids.
Life history
The life cycle of Dictyosphaeria exhibits both biphasic and isomorphic alternation of generations. This involves quadriflagellate zoospores, as well as isogamous and biflagellate gametes. Asexual reproduction through thalli fragmentation and possible parthenogenesis of gametes results in smooth surface thalli textures.[citation needed]
In addition, since this macroalgae is a large cell unit, mitotic division and cytokinesis were observed in the development of the zoospores. The unique process of cell division in this genus is observed in a study by Hori and Enomoto (1978). The mitotic spindle is placed centrally at the early course of the zooid differentiation. Prophase nuclei with centrioles were observed to be present during this stage only. Other mitotic stages are observed together in the network cytoplasm [5]
Distribution and habitat
Dictyosphaeria is found in tropical regions in shallow intertidal to subtidal areas. They grow on coral or rocky rubbles in reef flats where they can be the dominant macroalgae.[6]
Economic use and natural products
Dictyosphaeria, particularly the species D. cavernosa, is used for fish bait and animal feed.[7]
Natural products such as the novel metabolite dictyosphaerin, a bicyclic lipid compound were extracted from Dictyosphaeria, particularly D. sericea. This compound is being studied for its potential application in both scientific and medical applications.[8] In addition, Dictyosphearia also harbors microorganisms such as the fungal species that belong to the genus Penicillium. A study by Bugni et al. (2008) has shown that isolated fungal specimens from the species D. versluysii were found to produce novel metabolites including the polyketides dictyosphaeric acids A and B, and the anthraquinone carviolin.[9]