Phyllophora nervosa (D.C. Grev., 1830)
Synonyms: Fucus nervosus De Candolle, 1805; Phylophora rubens (Good. et Wood.) Grev., F. nervosa Hauck, 1885; Phyllophora crispa (Huds.) Dixon.
Common names: Rom: Filofora; Russ: Fillofora; Turk: Filofora.
Order (Scientific): GIGARTINALES.
Family (Scientific): PHYLLOPHORACEAE.
Taxonomic description: The thallus is formed by brushes of 50 cm. The base consists of spreading on the ground suckers or a small foot (sole) provided with short and branch twigs (sprigs, shoots) which have often joined and grown together forming a thicker strata. From the base rise vertical suckers with a short stem (cylindrical in the base and flat on the upper site). The stem passes over the lamellate site of the thallus. The shape of the lamella is linear and linear-oval with a densely central zone and small waved margins, abundantly branched; new lamellas appear on the old ones surface especially in its more densely upper site-pair of leaflets; a forked cleavage is often observed. Lamellas length 2-8 cm, 1-2.7 mm breadth. In a cross section are some rangers of small cells with thick walls, close to one another, which are permanently transformed into cortical small strata; cell ranges in the place of the leaflet formation is double those of the margins. Tetrasporangium, spermatangia and cystocarps develop into lengthening enation spherical of nemathece shape provided with pedicels, on the stem surface along both sites of the leaflets and near the lamella margins. The surface of the cystocarps is wrinkle-waved folded.
Black Sea Regional level: VU
Subregion level: VU
Habitats type, Critical habitats, Limiting factors: “Zernov’s field”; On rocky, gravely-pebbly grounds at depth of 0 to 60 m, at greater depths there are many agglomerations; the species belongs to south part of the northern area. A deterioration in water transparency reduces light penetration.
Biology: The formation of crystocarps is observed in summer.
Population trends: Severe reduction; all three species have been estimated on the Romanian shelf as 5,900 t in 1971-72. In Zernov’s Phyllophora field in the 1950s, the total biomass reached about 107 tonnes. In 1980, the biomass declined to 14·105 tonnes and in 1990 to 3-5·105 tonnes.
Threats: Decline in light energy penetration; eutrophication.
Conservation measures taken:
Conservation measures proposed: Improve ecological conditions in the central northwestern Black Sea; areas of the main Phyllophora beds to be closed to dragged fishing gear disturbing the bottom; declare ecological sanctuaries to protect unique associated fauna.
Compiled by: A.Bologa. A.Bavaru, G.Minicheva.