Preprint volume - SIBM

Pre-print Volume - Oral presentations
Topic 2: MARINE ORGANISMS AND ECOSYSTEMS AS MODEL SYSTEMS
crustacean decapods voraciously consume few days-weeks old P. lividus.
Unexpectedly, we found profound differences in predation rates among different
hermit crabs and among different crabs. The difference in the predation patterns among
species might depend on species-specific morphological and/or behavioural traits and
may have profound repercussions on the mortality of early-post settlement sea urchins
in natural conditions. As expected, predators were significantly more abundant in the
erect macroalgae assemblage and almost absent in barren areas. Our findings strongly
support the hypothesis that the absence of erect algae in a barren system may cause the
reduction of predators of P. lividus young-settlers, thus enhancing sea urchin recruit
survival and representing a self-perpetuating process for the stability of Mediterranean
barren systems. This study suggests different and complementary roles of small
invertebrate species in controlling the abundance of sea urchin recruits and underlines
the importance of the functional diversity of small invertebrates in this process. We
encourage future research aimed to understanding the factors involved in the
interaction strength between sea urchin recruits and their small invertebrate predators.
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