<span name="style_bold">Predator damage and shell size on the diadromous snail </span><span name="style_italic">Neritina virginea </span><span name="style_bold">(Gastropoda: Neritidae) in the Mameyes River, Puerto Rico. </span>We compared predators’ damage with shell size in live individuals and empty shells (n=5066) of the snail <span name="style_italic">Neritina virginea </span>in the Mameyes River (Puerto Rico, Greater Antilles). According to the literature and direct observations, damages on empty shells were attributed to predation by aquatic birds (e.g. <span name="style_italic">Gallinula chloropus</span>) and decapods (e.g. <span name="style_italic">Macrobrachium </span>spp<span name="style_italic">.</span>), while damages on live individuals were due to rasping by co-specifics and erosion. Predation by decapods and birds, as estimated by the proportion of empty shells, was low (2 and 0.36%, respectively). Shell size was significantly different between types of predators (range: decapods: 3.5-15.0mm, birds: 8.1-19.4mm). By comparing sizes of the empty shells and the live individuals, we concluded that decapods specialize on large groups of small migratory juveniles, while birds specialize on the largest resident individuals. Worn shells were highly frequent in both empty shells and live individuals, and sizes did not differ between samples. A comparison by slow-flow and fast-flow habitats showed that predators do not discriminate shell sizes between environments. However, the frequency of damage by birds and decapods was greater under slow-flow conditions. Despite of the little contribution of predation to the population dynamics in this species, predation might be an important driver of size-dependent behavioral responses such as upstream migration and microhabitat selection. Rev. Biol. Trop. 57 (4): 1069-1080. Epub 2009 December 01.), while damages on live individuals were due to rasping by co-specifics and erosion. Predation by decapods and birds, as estimated by the proportion of empty shells, was low (2 and 0.36%, respectively). Shell size was significantly different between types of predators (range: decapods: 3.5-15.0mm, birds: 8.1-19.4mm). By comparing sizes of the empty shells and the live individuals, we concluded that decapods specialize on large groups of small migratory juveniles, while birds specialize on the largest resident individuals. Worn shells were highly frequent in both empty shells and live individuals, and sizes did not differ between samples. A comparison by slow-flow and fast-flow habitats showed that predators do not discriminate shell sizes between environments. However, the frequency of damage by birds and decapods was greater under slow-flow conditions. Despite of the little contribution of predation to the population dynamics in this species, predation might be an important driver of size-dependent behavioral responses such as upstream migration and microhabitat selection. Rev. Biol. Trop. 57 (4): 1069-1080. Epub 2009 December 01.

Neritina virginea; gasterópodos migratorios; efectos dependientes de la talla; daños de conchas; depredación