Arroyo Hailuoto, N.L. (2002). Meiofauna asociada al alga "Laminaria ochroleuca" De la Pylaie en la isla de Mouro (Santander, Cantabria). [Meiofauna associated with the alga "Laminaria ochroleuca" De la Pylaie on the island of Mouro (Santander, Cantabria).]. Tesis Doctoral, Universidad Complutense de Madrid, Madrid, Spain. 179 pp. [In Spanish].
561291
Arroyo Hailuoto, N.L.
2002
Meiofauna asociada al alga "Laminaria ochroleuca" De la Pylaie en la isla de Mouro (Santander, Cantabria). [Meiofauna associated with the alga "Laminaria ochroleuca" De la Pylaie on the island of Mouro (Santander, Cantabria).]
Tesis Doctoral, Universidad Complutense de Madrid, Madrid, Spain.
Meiofauna constitutes a numerically significant element within benthic marine systems. On rocky shores, meiobenthic animals occur primarily within algal associations, although they are also abundant members of other types of microhabitats where sediment may accumulate—such as mussel beds, crevices, beneath boulders, or inside the empty shells of barnacles. They are sometimes found in facultative association with certain macrofaunal organisms, such as bryozoans or encrusting hydrozoans, within polychaete reefs, or within the mantle cavities of certain gastropods (Branch, 1974c).
Algal belts on rocky substrates offer a range of complex habitats that are heavily exploited by meiofauna. Even seagrasses—which possess a simpler structure than these algal belts—provide shelter to twice as many meiofaunal species as are found in the adjacent sediments (Hicks, 1986). A density of phytal meiofauna reaching approximately 10 million individuals per square meter is not uncommon and typically accounts for 10% of the macrobenthic biomass in these biotopes (Giere, 1993).
Meiofauna is invariably more abundant than macrofauna, although the latter generally dominates in terms of biomass. However, due to their rapid reproductive rates (Gerlach, 1978), meiobenthic organisms can be just as important in terms of secondary production, such as that of the macrofauna (Koop & Griffiths, 1982; McLachlan, 1983). Gerlach (1971) suggested that, for an equivalent biomass, the meiofauna accounts for approximately five times the total metabolism of the benthic macrofauna. Therefore, a biomass ratio of 5:1 is required for the energy requirements of the macrofauna to exceed those of the meiofauna. The biomass of the macrofauna in most systems is generally much greater than that required to reach this 5:1 ratio; however, in very shallow waters—where macrophytic communities are frequently found—the macrofauna-to-meiofauna ratio approaches 1 (Gerlach, 1971; Thiel, 1975), meaning that the meiofauna plays a significant energetic role in these environments (Coull & Bell, 1979). In a comparative study examining the distribution and abundance of macrofauna and meiofauna along a rocky coastline, Gibbons and Griffiths (1986) estimated that the macrofauna accounted for 75% of the total secondary production, while the meiofauna contributed 25%. In numerical terms, the meiofauna tended to be approximately three orders of magnitude more abundant than the macrofauna. Gibbons and Griffiths (1986) found that meiofaunal densities were closely linked to algal biomass; consequently, the meiofauna-to-macrofauna ratio varied in relation to this biomass, with the meiofauna being most abundant in areas characterized by high algal cover. Overall, the meiofauna constituted between 1.4% and 61% of the macrofauna, with the highest abundances observed in the upper barnacle zone. Meiofauna therefore represents the most abundant group of metazoans in the marine benthic system, extending from the intertidal zone to abyssal depths, with an average density on the order of ten million individuals per square meter—reaching values ??of up to 25 million in muddy sediments (Vernberg and Coull, 1981).
