Predicting the interactions between “ecologically equivalent” indigenous and nonindigenous brachyurans

Abstract

Predictive models used to determine the impacts of nonindigenous brachyurans on their “ecological equivalents” in marine ecosystems are sorely lacking. Determining the spatial and temporal extent and magnitude of such impacts by nonindigenous species is difficult because of the broad range of qualitative and quantitative criteria currently used to describe their effects. Forecasting potential impacts requires the development of predictive models that incorporate the effects of interspecific interactions and the mechanisms that give rise to these interactions. Successful validation of such models requires improved techniques for measuring and estimating the functional responses on bioenergetic processes across species compositions, abundances, and environmental conditions. Species-specific information used to support predictive modeling of nonindigenous brachyurans is currently heavily biased towards (i) estimating per capita consumption and growth rates in laboratory conditions and (ii) incorporating the effects of abiotic and biotic factors on these measures. Robust predictive models require repetitive experimentation that advances the understanding of species’ interactions (beyond consumption alone) across variable densities and considers their effects across different spatial and temporal scales.

Invasive versus native brachyuran crabs in a European rocky intertidal: respiratory performance and energy expenditures

“…The ecology and physiology of C. maenas is well studied (e.g., Crothers 1967;Roman and Palumbi 2004;Breen and Metaxas 2012 and references therein). Ecological information on H. sanguineus is growing, mostly from invaded areas, where increasing numbers of H. sanguineus share habitats and possibly compete for resources with C. maenas (for native areas, e.g., Fukui 1988;Lohrer et al 2000a; for invaded areas, e.g., McDermott 1998;Jensen et al 2002;Lohrer and Whitlatch 2002;Epifanio 2013 and references therein;Jungblut et al 2017).…”

“…Ecological information on H. sanguineus is growing, mostly from invaded areas, where increasing numbers of H. sanguineus share habitats and possibly compete for resources with C. maenas (for native areas, e.g., Fukui 1988;Lohrer et al 2000a; for invaded areas, e.g., McDermott 1998;Jensen et al 2002;Lohrer and Whitlatch 2002;Epifanio 2013 and references therein;Jungblut et al 2017). However, physiological data of H. sanguineus are rather scarce (Breen and Metaxas 2012) and stem mostly from the invaded US east coast. For instance, the species was identified as an income breeder, meaning that it utilizes energy ingested during reproductive times directly for egg production (Griffen et al 2012).…”