Ecology, physiology, feeding and trophic role of squat lobsters

Abstract

Squat lobsters are conspicuous representatives of the benthic fauna in diverse marine environments.They may occur as solitary individuals or as dense benthic aggregations, sometimes associated withcomplex substrata. A few shallow-water species occur in massive pelagic swarms during a specificontogenetic phase or during their entire life. These swarms are often associated with fronts or internalwaves. In deep waters the occurrence of squat lobsters is determined by the availability of foodsources such as organic matter falls or seeps. Some squat lobster species oxyregulate and can copewith low oxygen environments. This ability changes ontogenetically, with the oldest/largest animalsbeing best capable of surviving these extreme conditions. Air exposure as a consequence of fishingactivities can cause physiological stress and increase mortality rates. Squat lobsters consume manydifferent food resources, as deposit feeders, predators, scavengers, carnivorous, algal grazers,suspension feeders or even cannibals. They obtain carbon and nitrogen from different sources:photosynthetic, chemosynthetic or mixed. Feeding rates of squat lobsters vary on daily, seasonal andannual time scales, and oxygen consumption during digestion depends on the ingested food types.Squat lobsters play an important role as recyclers in many sedimentary ecosystems, either by reincorporatingorganic matter into the food web or by producing highly nutritive faeces. Feeding onprimary producers, bacteria or detritus, and being consumed by several top predators, squat lobstersrepresent a direct trophic short-cut in many marine food webs.