The following account on foods and feeding is divided “family-wise” into studies on the Talitridae, Corophiidae, and Caprellidae.  Talitrids are mainly herbivorous, feeding on seaweeds and other plant matter.  High-intertidal species on sand beaches live in temporary, loosely fashioned burrows in the sand, and consume algae washed ashore by waves.  Corophiids inhabit burrows on sand/mudflats and generally deposit-feed.  Caprellids feed by browsing, filter-feeding, predation, scavenging, and scraping.

Laboratory studies on feeding preferences of 2 supralittoral species Traskorchestia traskiana and Megalorchestia californiana at the Bamfield Marine Sciences Centre, British Columbia disclose that both significantly prefer wrack seaweeds over fresh seaweeds (see histograms).  Wrack is characterised by toughness, reduced nitrogen content, and high mineral content, and could reasonably be thought to have reduced palatability in comparison with fresh seaweed.  However, drying and decaying seaweeds are colonised by bacteria and fungi that may themselves be more digestible than fresh seaweed tissue.  Moreover, wrack has greatly reduced water content in comparison with fresh tissue; hence, has several times more organic content per “bite” than fresh seaweed.  It is also possible that defensive secondary metabolites in the seaweeds degrade during drying, as is known for terrestrial plants so, overall, the amphipods appear to be getting a superior diet when consuming wrack.  Pennings et al. 2000 Can J Zool 78: 1918.

NOTE  seaweeds cast up on the shore by waves and aged; often dried to crispy or leathery texture by the sun

NOTE  chemicals in a plant that play no known role in the plant’s metabolism; rather, are thought to be involved as deterrents against consumers.  Secondary metabolites are absent in green seaweeds and, in brown and red seaweeds, are present mainly as phenolics and in various forms of terpenes, respectively