Variaciones verano — invierno de la macrofauna de Arena en Playa Morrillos (Norte Chico, Chile)

Publisher Website
Google Scholar
Abstract
Summer and winter variations of the macrofauna of sandy beach in Morrillos, Norte Chico, Chile Vertical zonation, density and diversity of the macrofauna were studied in a sandy beach (Morrillos, Chile) during summer (January 1974) and winter (July 1975), to observe the fluctuations occurring in these seasons. Three faunistic fringes are described, according to the animals most frequently found in the samplings: (1) Upper Fringe, including Tylos sp. (Isopoda) and Orchestoidea tuberculata (Am‐phipoda); (2) Middle Fringe, where Hemipodus sp. (Polychaeta) and Excirolana braziliensis (Isopoda) predominate; (3) Lower Fringe, which includes Nephtys impressa (Polychaeta), Bathyporeiapus magellanicus (Amphipoda), Emerita analoga (Anomura) and Mesodesma donacium (Bivalvia). In January (summer), a density of 11,031 individuals in a sampling area of 25m2 were collected, of these animals 16 species were identified out of unidentified Oligochaeta, Nemertinea and insect pupae. The slope was 1:25 m. The well‐sorted sand had a mean particle size corresponding to fine sand. In July (winter), a density of 5,490 individuals in a sampling area of 17 m2 were found, belonged to 10 species and unidentified Coleoptera and Nemertinea. The slope was 1:22 m and the moderately sorted sand had a mean particle size corresponding to medium sand. The data are discussed and compared with similar studies carried out in Chile and in tropical and semitropical areas.