@article {2279, title = {The behavioural and sensory ecology of Agaronia propatula (Caenogastropoda: Olividae), a swash-surfing predator on sandy beaches of the Panamic faunal province}, journal = {Journal of Molluscan Studies}, volume = {2012}, year = {2012}, pages = {1-11}, abstract = {

The genus Agaronia includes dominant predators in the eulittoral zone of dissipative sandy beaches of the tropical Eastern Pacific, which show specific adaptations to this environment such as swash-surfing locomotion. We studied A. propatula in its natural habitat in El Salvador and Costa Rica, and performed field experiments to obtain insights into its ecology, behaviour and sensory physiology. Agaronia propatula is not attracted by carrion and preys mostly on the ubiquitous beach snail Olivella semistriata. This, however, reflects community composition rather than prey specialization; A. propatula is an investigative hunter and will, quite literally, attack everything that moves (with the notable exception of echinoids). Prey is identified at short range by tactile and, to a lesser degree, by chemosensation located in the propodium. We found no evidence for long-distance sensory capabilities; A. propatula rather seems to rely on the regular physical structure of its wave-dominated environment when it moves between its shallow subtidal resting zone and its upper intertidal hunting grounds where potential prey predictably congregates. On the other hand, behavioural patterns such as the rapid yet haphazard cruising of foraging individuals, or the complex prey capture sequence in which the prey is transferred to a metapodial pouch, are similar in A. propatula and Oliva. Thus, our results lead us to speculate that the development of behavioural features that proved adaptive in the intertidal environment was essential in the evolution of Agaronia from Oliva-like ancestors.

}, keywords = {behaviour, ecology, Panamic, Recent}, url = {http://mollus.oxfordjournals.org/content/early/2012/04/28/mollus.eys006.full.pdf+html}, author = {Cyrus, A.Z. and Rupert, S.D. and Silva, A.S. and Graf, M. and Rappaport, J.C. and Paladino, F.V. and Peters, W.S.} } @article {2753, title = {What can we learn from confusing Olivella columellaris and O. semistriata (Olivellidae, Gastropoda), two key species in panamic sandy beach ecosystems?}, journal = {Biota Neotropica}, volume = {12}, year = {2012}, pages = {101-113}, abstract = {

Olivella columellaris\ (Sowerby 1825) and O. semistriata (Gray 1839) are suspension-feeding, swash-surfing snails on tropical sandy beaches of the east Pacific. While they often are the numerically dominant macrofaunal element in their habitats, their biology is poorly understood; the two species actually have been confused in all of the few publications that address their ecology. Frequent misidentifications in publications and collections contributed also to an overestimation of the geographic overlap of the two species. To provide a sound taxonomic basis for further functional, ecological, and evolutionary investigations, we evaluated the validity of diagnostic traits in wild populations and museum collections, and defined workable identification criteria. Morphometric analysis demonstrated that shell growth is allometric in O. columellaris but isometric in O. semistriata, suggesting that the species follow distinct developmental programs. The taxonomic confusion is aggravated by the existence of populations of dwarfish O. semistriata, which originally had been described as a separate species, O. attenuata (Reeve 1851). At our Costa Rican study sites, the occurrence of such dwarfish populations correlates with low wave energies but not with predation pressure and anthropogenic disturbances, indicating significant ecological plasticity in the development of O. semistriata.

}, keywords = {Panamic, Recent}, author = {Troost, A.I. and Rupert, S.D. and Cyrus, A.Z. and Paladino, F.V. and Dattilo, B.F. and Peters, W.S.} } @article {3753, title = {Autotomy of the posterior foot in Agaronia (Caenogastropoda: Olividae) occurs in animals that are fully withdrawn into their shells}, journal = {Journal of Molluscan Studies}, volume = {77}, year = {2011}, pages = {437-440}, keywords = {autotomy}, author = {Rupert, S.D. and Peters, W.S.} }