Phyllophora nervosa (D.C. Grev., 1830)

Phyllophora nervosa imageSynonyms: 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.

Phyllophora nervosa arealIUCN Status:
    World level:
    Black Sea Regional level: VU
    Subregion level: VU

Distribution:

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.

References:

  1. Bavaru A., Bologa A. S., Skolka H. V., 1991 - A checklist of the benthic marine algae (except Diatoms) along the Romanian shore of the Black Sea. Rev. Roum. Biol. - biol. veget., 36, 1-2, 7-22.
  2. Bologa A. S., 1987-88 - Annotated bibliography on the macrophytobenthos along the Romanian Black Sea coast (1881-1986). Cercetari marine, 20/21, 353-384.
  3. Bologa A. S., Bodeanu N., Petran A., Tiganus V., Zaitsev Yu. P., 1995 - Major modifications of the Black Sea benthic and planktonic biota in the last three decades. Bull. Inst. oceanogr., Monaco, no. special 15, 85-110.
  4. Vasiliu F., 1984 - Cauze si consecinte ale starii actuale a populatiilor de alge perene de la litoralul romanesc al Marii Negre. Rev. Muz. Monument; 5.
  5. Vasiliu F., Bodeanu N., 1972 - Repartition at quantite d’Algues rouges du genre Phyllophora sur le platforme continentale roumain de la mer Noire. Cercetari marine, 3,47-52.
  6. Zaitsev, Yu., 1992 - Recent changes in the trophic structure of the Black Sea. Fishery oceanography, 1, 2: 180-189.
  7. Zinova A. D., 1967 - Opredelitel’ zelenykh, burykh i krasnykh vodoroslei iuzhnykh morei SSSR, Izd. “Nauka”, Moskva - Leningrad, 398 pp.
  8. Kalugina-Gutnik A.A. Phytobenthos of the Black Sea.-Kiev.:Naukova Dumka,1975.-245 p.
  9. Kaminer K.M. Degradation of the phytocoenoses of Dzharylgachskiy Bay of the north-western Black Sea as a result of several years anthropogenic load. In: Hydrobiological investigation on the Ukraine in XI Five-Year Plan.-Kiev, 1987.-P.41-42.
  10. Katukov A.B. Phyllophora`s field as indicators condition of the ecosystem. In : Systems analysis and modelling processes on the shelf of the Black Sea , 1983-Sevastopol.-Akad. Nauk.Ukr.SSR.-P.140-147.
  11. Zaitsev Yu.P. Recent changes in the trophic structure of the Black Sea // Fisheries Oceanography, 1992.-V.1,N2.-P.180-189.
  12. Zinova A.D. Definition of green,brown and red algae of the southern seas of the USSR.-Leningrad: Nauka,1967.-397 p.

Compiled by: A.Bologa. A.Bavaru, G.Minicheva.