Composition and abundance patterns are described for the plankton assemblages in a shallow submarine cave on the Salento peninsula side of the Otranto Channel (SE Italy). A total of 232 taxa were recognized. The cave plankton appeared more affected by huperbenthos than the outside plankton. Mysidacea represented the most conspicuous component of the cave plankton , with two species typical of Salento caves. Harpacticoida, together with asexual algal propagules, dominated the plankton of the cave numerically, whereas Calanoida and Cyclopoida along with mollusc veligers, characterized the plankton in the outside sector. While the mysid Siriella jaltensis was found outside the cave in nocturnal samples, Hemimysis margalefi appeared to migrate simply along the axis of the cave, never leaving it during night. The community composition changed seasonally over the 1-year period. Therte was a clear horizontal partitioning of the plankton, with significant differences between the two stations inside the cave. Higher water turbulence probably explains the presence of asexual propagules even at the inner station. An explanation of the benthos impoverishment has been proposed as an alternative to the current “trophic depletion” theory.
THE PLANKTON OF A SHALLOW SUB-MARINE CAVE ("GROTTA DI CIOLO", SALENTO PENINSULA, S-E ITALY)
MOSCATELLO, Salvatore;BELMONTE, Genuario
2007-01-01
Abstract
Composition and abundance patterns are described for the plankton assemblages in a shallow submarine cave on the Salento peninsula side of the Otranto Channel (SE Italy). A total of 232 taxa were recognized. The cave plankton appeared more affected by huperbenthos than the outside plankton. Mysidacea represented the most conspicuous component of the cave plankton , with two species typical of Salento caves. Harpacticoida, together with asexual algal propagules, dominated the plankton of the cave numerically, whereas Calanoida and Cyclopoida along with mollusc veligers, characterized the plankton in the outside sector. While the mysid Siriella jaltensis was found outside the cave in nocturnal samples, Hemimysis margalefi appeared to migrate simply along the axis of the cave, never leaving it during night. The community composition changed seasonally over the 1-year period. Therte was a clear horizontal partitioning of the plankton, with significant differences between the two stations inside the cave. Higher water turbulence probably explains the presence of asexual propagules even at the inner station. An explanation of the benthos impoverishment has been proposed as an alternative to the current “trophic depletion” theory.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
