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

• Published in: PeerJ
• Main Authors: Hudson, David M., Sexton, D. Joseph, Wint, Dinsdale, Capizzano, Connor, Crivello, Joseph F.
• Other Authors: Schwenk Fund, National Science Foundation’s Research Experiences for Undergraduates program
• Format: Article in Journal/Newspaper
• Language: English
• Published: PeerJ 2018
• Subjects: North Atlantic
• Online Access: http://dx.doi.org/10.7717/peerj.5446; https://peerj.com/articles/5446.pdf; https://peerj.com/articles/5446.xml; https://peerj.com/articles/5446.html

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.