Physiological and behavioral response of the Asian shore crab, Hemigrapsus sanguineus, to salinity: implications for estuarine distribution and invasion.

David M. Hudson,D. Joseph Sexton,Connor Capizzano,Dinsdale Wint,Joseph F. Crivello

doi:10.7717/peerj.5446

Abstract

The invasive Asian shore crab, Hemigrapsus sanguineus, is ubiquitous in the rocky intertidal zone of the western North Atlantic. A likely contributor to this colonization is that H. sanguineus is able to handle a wide range of salinities, and is thus more likely to spread through a greater geographic area of estuaries. This study investigated the salinity effects on this animal by observing survival across a range of salinities, the maintenance of hemolymph osmolality under different salinities, and behavioral preference for and avoidance of salinities. H. sanguineus showed high survival across a broad range of salinities, had little change in hemolymph osmolality over a short-term salinity shock, and behaviorally distinguished between salinities when presented with a choice, under both acclimation salinities of 5 PSU or 35 PSU. Such results suggest H. sanguineus has a hardiness for the rapid changes in salinity that happen in the intertidal zone, yet is capable of physically moving to a more optimal salinity. This enhances their competitiveness as an invader, particularly surviving lower salinities that present challenges during high-precipitation events in rocky intertidal areas, and partially explains this species’ dominance in this habitat type.

Highlights

The invasive Asian shore crab, Hemigrapsus sanguineus, is a successful invasive decapod crustacean species which is found in estuaries and open coasts in areas along the western North Atlantic and western Europe, displacing resident species (Lohrer et al, 2000; Brousseau et al, 2002; Van den Brink, Wijnhoven & McLay, 2012; Landschoff et al, 2013; Gothland et al, 2013; Gothland et al, 2014)
Given acclimation conditions have been shown to modify preference behavior in other crustacean species (Gross, 1957; Hernández et al, 2006), we investigated whether acclimation conditions affected salinity preference
When survival data were grouped into broader salinity designations for ease of interpretation and applicability to representative scenarios, the non-parametric Kaplan–Meier estimator indicated that H. sanguineus survival functions for the fresh, estuarine, and seawater salinity groups were distinct (Fig. 1), which was reaffirmed by the Peto & Peto test against all three survival functions (χ 2 = 26.8, d.f . = 2, p 0.001)

Summary

Introduction

The invasive Asian shore crab, Hemigrapsus sanguineus, is a successful invasive decapod crustacean species which is found in estuaries and open coasts in areas along the western North Atlantic and western Europe, displacing resident species (Lohrer et al, 2000; Brousseau et al, 2002; Van den Brink, Wijnhoven & McLay, 2012; Landschoff et al, 2013; Gothland et al, 2013; Gothland et al, 2014). The species has become the most abundant crab in the rocky intertidal in New England since it was first found in New. How to cite this article Hudson et al (2018), Physiological and behavioral response of the Asian shore crab, Hemigrapsus sanguineus, to salinity: implications for estuarine distribution and invasion. Jersey in 1988 (McDermott, 1998; Williams & McDermott, 1990; Lohrer & Whitlatch, 2002; Kraemer et al, 2007; O’Connor, 2014). Previous work in this lab and by others investigated the behavioral response of the intertidal and subtidal community to this species’ presence (Epifanio, 2013; Hudson, Reagan & Crivello, 2016). Beyond community interactions, this species’ broad salinity tolerance could be contributing to its success as an invader and for the invasiveness of the genus more broadly (Tsai & Lin, 2007; Urzúa & Urbina, 2017), so this work aimed to evaluate its survival and behavior with respect to salinity

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Conclusion