Energy saving through trail following in a marine snail

Abstract

A major goal of ecology is to determine the causes of the latitudinal gradient in global distribution of species richness. Current evidence points to either energy availability or habitat heterogeneity as the most likely environmental drivers in terrestrial systems, but their relative importance is controversial in the absence of analyses of global (rather than continental or regional) extent. Here we use data on the global distribution of extant continental and continental island bird species to test the explanatory power of energy availability and habitat heterogeneity while simultaneously addressing issues of spatial resolution, spatial autocorrelation, geometric constraints upon species' range dynamics, and the impact of human populations and historical glacial ice-cover. At the finest resolution (1 degree), topographical variability and temperature are identified as the most important global predictors of avian species richness in multi-predictor models. Topographical variability is most important in single-predictor models, followed by productive energy. Adjusting for null expectations based on geometric constraints on species richness improves overall model fit but has negligible impact on tests of environmental predictors. Conclusions concerning the relative importance of environmental predictors of species richness cannot be extrapolated from one biogeographic realm to others or the globe. Rather a global perspective confirms the primary importance of mountain ranges in high-energy areas.

Effect of γ-amino Butyric Acid on Limpet Populations: Towards the Future Management and Conservation of Endangered Patellid Species

“…Our main hypothesis was that GABA may be present in the pedal mucus of limpets (as seen in Haliotis sp) (Laimek et al, 2008). Mucus has been found to persist around 5 d in Patella vulgata (Davies et al, 1992) and up to 2.5 wk in the case of Littorina littorea (Davies and Blackwell, 2007). Taking this into account, the application of the GABA solution was performed weekly during February and March 2009, coinciding with the P. ferruginea recruitment period (Espinosa, 2006).…”

Computer simulations of high shore littorinids predict small-scale spatial and temporal distribution patterns on rocky shores

“…35 µm thick, double trails are ca. 47 µm thick at the centre of the trail (Davies & Blackwell 2007). The simulated mucus also contained directional information, indicating the direction in which it was laid.…”

“…After each tidal cycle decay of mucus trails occurred. This decay was based on data for Littorina littorea (Davies & Blackwell 2007). The decay was modelled as:…”

Diet preferences of the Aglajidae: a family of cephalaspidean gastropod predators on tropical and temperate shores

“…Motile organisms secrete mucus to aid in crawling or as a protective mechanism (e.g. opisthobranchs, nematodes, platyhelminths, annelids, gastropods) (Brusca & Brusca, 2003;Hickman et al, 1993), leaving behind mucous trails that can be located and traced by aglajids using their sensorial organs (Paine, 1965;Kohn, 1983;Davies & Blackwell, 2007;Terrence et al, 2013).…”