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Uttieri, Marco
(2006).
DOI: https://doi.org/2006%20Marco%20Uttieri
Abstract
Small planktonic copepods (< 1 mm) play a pivotal role in the functioning of marine ecosystems. Among them, the calanoid Clausocalanus furcatus is one of the dominant species in epipelagic waters of tropical and sub-tropical oceans. Its swimming motion is rather unique among planktonic copepods, being characterized by a continuous looping movement performed at very high speed.
The aim of this PhD thesis was to investigate some aspects of the swimming behaviour of C. furcatus adult female that could shed light on its small-scale interactions with the surrounding environment. In particular, the work was focused on the mechanisms regulating the perception and capture of prey items, in order to understand the success of this species in oligotrophic regions. To this purpose, four different approaches have been utilised:
- the numerical characterization of the trajectories performed by freely swimming C. furcatus adult females in presence of dinoflagellate cells and in association with capture events;
- the reconstruction of the perception area and of the mechanisms involved in the capture of prey items;
- the morphological investigation of the sensory structures present on the first antennae, which bear mechano- and chemo-sensors involved in the perception of external cues;
- the evaluation of the sensory performance of the mechanoreceptors on the first antennae by means of electrophysiological experiments.
The results of these investigations concur in depicting a coherent scenario. In C. furcatus, the modalities of detecting and capturing prey seem to be forged to efficiently exploit food particles when they are grouped in small patches, and are aimed at maximising the success of C. furcatus in oligotrophic environments.