Habitat-modulated shell shape and spatial segregation in a Patagonian false limpet (Siphonaria lessonii)

LIVORE, JP; MENDEZ, MM; BIGATTI, G; MÁRQUEZ, F

MARINE ECOLOGY PROGRESS SERIES

INTER-RESEARCH

Año: 2018 vol. 606 p. 55 - 63

0171-8630

Environmental stressors that characterize intertidal habitats, such as exposure to air,thermal amplitude and wave action, influence biological patterns of distribution. The effects ofthese stressors on intertidal organisms are often associated with their shape and size. Rocky intertidalshores in Patagonia are particularly stressful environments in which a species of false limpetoccurs abundantly in 2 contrasting habitats. Here we describe size and shape segregation of thefalse limpet Siphonaria lessonii across multiple shores on 2 contrasting shore levels where limpetsare abundant, namely the high (HT) and mid (MT) intertidal. We tested for differences in resistanceto desiccation, and recovery from heat stress, and were able to define 2 ecomorphs using classicand geometric morphometrics analysis. Individuals from the HT lost significantly less water understressful heat conditions, and showed higher recovery rates than those from the MT. Limpets fromthe HT had a broad aperture, flatter margin and larger size. In contrast, individuals from the MThad a narrow aperture, arched margin and smaller size. Together these results suggest the existenceof 2 ecomorphs modulated by each contrasting habitat. The observed small-scale spatial segregationof the 2 ecomorphs may provide ecological advantages by allowing the exploitation ofresources from 2 different habitats. The 2 ecomorphs may provide S. lessonii with a broad thermaltolerance breadth, potentially improving resistance of the species to extreme climatic events.