Corophium volutator

Researched ByKen Neal & Penny AvantData Supplied ByMarLIN
Refereed byThis information is not refereed.
Taxonomy
Scientific nameCorophium volutatorCommon nameA mud shrimp
MCS CodeS605Recent SynonymsNone
PhylumCrustaceaSubphylum
SuperclassClassEumalacostraca
SubclassPeracaridaOrderAmphipoda
SuborderGammarideaFamilyCorophiidae
GenusCorophiumSpeciesvolutator
Subspecies  
Additional InformationThe morphology of the male and female antennae differs significantly and for identification refer to the appropriate key, e.g. Lincoln (1979).
Taxonomy References Howson & Picton, 1997, Lincoln, 1979, Fish & Fish, 1996, Hayward & Ryland, 1995b, Hayward et al., 1996
General Biology
Growth formArticulateFeeding methodSee additional information, Surface deposit feeder, Active suspension feeder, Grazer (grains/particles)
Mobility/MovementSwimmer, Crawler, BurrowerEnvironmental positionInfaunal
Typical food typesParticulate organic matter, epipelic (=living on fine sediment) and epipsammic (= living on sand) bacteria and diatoms.HabitBurrow dwelling
BioturbatorFlexibilityHigh (>45 degrees)
FragilityIntermediateSizeSmall(1-2cm)
HeightNot relevantGrowth Rate8 - 11 mm/year
Adult dispersal potential1km-10kmDependencyIndependent
SociabilityGregarious
Toxic/Poisonous?No
Additional InformationAbundance
Corophium volutator is one of the most abundant organisms in estuarine mudflats reaching densities of 100,000 m² in the Stour Estuary, Suffolk (Hughes, 1988). Densities vary with geographical region and season. In Gullmarsfjorden, Wadden Sea winter densities are 100 m² and rise to 1400 m² in the summer (Flach & de Bruin, 1993). In the Crouch Estuary in southeast England, Corophium volutator number 6,000 m² in winter and rise to 50,000 m² in the summer (Gerdol & Hughes, 1993).

Predation
Variations in density are the result of predation and subsequent recovery of Corophium volutator. Corophium volutator is an important food source for dunlin (Calidris alpina) (Jensen & Kristensen, 1990), redshank (Tringa totanus) (Hughes, 1988; Raffaelli et al., 1991), shelduck (Tadorna tadorna) and flounder (Platichthys flesus) and these predators can consume 55% of annual Corophium volutator production (Raffaelli et al., 1991). Corophium volutator is also fed upon by the brown shrimp (Crangon crangon) and the green shore crab (Carcinus maenas) which can consume 57% and 19% of Corophium volutator production respectively (Flach & de Bruin, 1994). In the summer months, as the tide recedes, male Corophium volutator crawl on the surface of the mud, searching for females (Fish & Mills, 1979; Hughes, 1988; Forbes et al., 1996), making them more vulnerable to predation. In North American estuaries, the semipalmated sandpiper (Calidris pusilla) can consume 50 males per minute as they follow the ebbing tide (Brown et al., 1999).

There is no dispersive larval phase in the life history of Corophium volutator, instead, the embryos develop in a ventral thoracic brood pouch and emerge as miniature replicas of their parents and build a burrow off that of the parent (Hughes, 1988). Reproduction ceases below 7°C (McLusky, 1968) so, in the winter, predation significantly decreases the density of Corophium volutator.

Corophium volutator has the habit of swimming when immersed, which makes them available as prey for the common goby (Pomatoschistus microps) (Flach & de Bruin, 1994), herring (Clupea harengus), sprat (Sprattus sprattus) and smelt (Osmerus eperlanus) (Essink et al., 1989). The swimming behaviour of Corophium volutator has been reported by several authors. In the Ems Estuary, Wadden Sea, it was estimated that 0.06% of the population (3 x 108 individuals) swim on the flood of each tide, leading to a net landward movement of the population (Essink et al. 1989). In the Stour Estuary, southeast England, Corophium volutator was found to swim only at night, on or around spring tides and only between May and August. It was estimated that on any one tide 6-19% of the population swam and that it was mainly immature animals that swam (Hughes, 1988). Holmström & Morgan (1983a) also found this species swimming at spring tide, mainly on the ebb just after high tide. Corophium volutator is a poor swimmer and is vulnerable to predation whilst in the water column, so there must be a benefit to swimming that outweighs the risk of predation. Hughes (1988) proposed several theories as to why Corophium volutator would elect to swim:

  1. as a means of dispersal to prevent inbreeding;
  2. to prevent intrasibling competition;
  3. in response to diminishing food supplies in high density areas, or
  4. females may swim to release their young.
Feeding
Corophium volutator ingests particles 4 -63 µm in diameter. Food consists of bacteria, diatoms and particulate organic matter (POM) (Gerdol & Hughes, 1994a; Hughes, 1988; Jensen & Kristensen, 1990). There has been some disagreement in the literature about which of these is the most important in the diet. Diatoms are crushed individually to avoid ingestion of siliceous frustules, thus it is difficult to estimate rate of diatom consumption by Corophium volutator (Gerdol & Hughes, 1994a). Feeding occurs at all stages of the tide, suspension feeding at high tide and deposit feeding at low tide. Three modes of feeding have been recorded in Corophium volutator.
  1. Suspension feeding from a current generated by the pleopods (Hughes, 1988). In this way an individual can irrigate its burrow at a rate of 25-100 ml per hour (Limia & Rafaelli, 1997).
  2. Deposit feeding by leaving the burrow and scraping surface detritus and microorganisms into the burrow with the second antennae, the current generated by the pleoplods then passes this material over the mouth parts(Hughes, 1988).
  3. Epipsammic browsing, where the microbial biofilm is scraped off individual sediment grains (Gerdol & Hughes, 1994a, 1994b).
Biology References Hughes, 1988, Essink et al., 1989, Jensen & Kristensen, 1990, Raffaelli et al., 1991, Gerdol & Hughes, 1993, Flach & de Bruin, 1993, Holmström & Morgan, 1983a, Flach & de Bruin, 1994, Gerdol & Hughes, 1994a, Gerdol & Hughes, 1994b, Forbes et al., 1996, Fish & Mills, 1979, Limia & Raffaelli, 1997, Brown et al., 1999, McLusky, 1968
Distribution and Habitat
Distribution in Britain & IrelandWidely distributed on all coasts of Britain. Widely separated records in Ireland.
Global distributionNorth Atlantic, American and European coasts; from western Norway to the Mediterranean and the Black Sea and Azov Sea. There is also a Japanese variety, Corophium volutator orientalis (Omori & Tanaka, 1998).
Biogeographic rangeNot researchedDepth rangeIntertidal
MigratoryNon-migratory / Resident
Distribution Additional InformationThe distribution of Corophium volutator within estuaries changes with season and hydrodynamic conditions. Because of the flood tide swimming habit of Corophium volutator in certain areas (see adult general biology), it is often concentrated within creeks and embayments and all but absent from mudflats even though they are suitable habitat. In the Ythan Estuary, Corophium volutator were found to move in and out of areas depending on salinity. In the summer when freshwater input was low, Corophium volutator was much more widespread than in the winter when high rainfall reduced the interstitial salinity and made certain areas uninhabitable (McLusky, 1968). This pattern is presumably repeated in other estuaries as well.
Substratum preferencesSandy mud, Muddy sand, MudPhysiographic preferencesEstuary, Open coast
Biological zoneUpper Eulittoral, Mid Eulittoral, Lower Eulittoral, Sublittoral FringeWave exposureSheltered, Very Sheltered, Extremely Sheltered
Tidal stream strength/Water flowWeak (<1 kn), Very Weak (negligible)SalinityReduced (18-30 psu), Variable (18-40 psu), Full (30-40 psu), Low (<18 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)III 
Distribution References Lincoln, 1979, Fish & Fish, 1996, Hayward & Ryland, 1995b, Hayward et al., 1996, Bruce et al., 1963, Hughes & Gerdol, 1997, Omori & Tanaka, 1998, McLusky, 1968
Reproduction/Life History
Reproductive typeGonochoristic Developmental mechanismDirect Development
Reproductive SeasonSee additional informationReproductive LocationAdult burrow
Reproductive frequencyAnnual episodic Regeneration potentialNo
Life span<1 yearAge at reproductive maturity<1 year
Generation time<1 yearFecundityTo ca 50
Egg/propagule sizeInsufficient informationFertilization typeInternal
Larvae/Juveniles
Larval/Juvenile dispersal potential<10mLarval settlement periodNot relevant
Duration of larval stageNot researched  
Additional InformationReproductive season
Corophium volutator lives for a maximum of one year (Hughes, 1988) and females can have 2-4 broods in a lifetime (Conradi & Depledge, 1999). Populations in southerly areas such as the Dovey Estuary, Wales or Starrs Point, Nova Scotia have two reproductive episodes per year. Those populations in colder, more northerly areas such as the Ythan Estuary, Scotland or in the Baltic Sea only have one (Wilson & Parker, 1996; Table 1). Gravid females first appear in March with peak numbers occurring in May. These females, having successfully over-wintered and reproduced, die out during June. The juveniles born in May undergo rapid growth and maturation to reproduce from July to September and generate the next over wintering population (Fish & Mills, 1979).
Reproductive cycle.
Female Corophium volutator require the presence of a male to mate and must moult to become ovigerous (McCurdy et al., 2000). Males search for females over the mud at low tide on spring tides (Fish & Mills, 1979) and enter burrows of mature females. Fertilization is internal by copulation and the female has to moult before the male can copulate, often leading to males guarding and fighting over females (Forbes et al., 1996). Fertilized eggs are deposited in a ventral thoracic brood pouch where the embryos develop over the following 14 days and are released as juveniles on the spring tide (Fish & Mills, 1979). Brood sizes are 20 -52 embryos (Fish & Mills, 1979; Jensen & Kristensen, 1990).
Populations worldwide generally have a 1:1 sex ratio, but in the Bay of Fundy, the sex ratio was highly skewed towards females. Only 16 - 36% were male and this was not due to higher predation pressure on males by wading birds (Schneider et al., 1994).
Reproduction References Hughes, 1988, Jensen & Kristensen, 1990, Schneider et al., 1994, Wilson & Parker, 1996, Forbes et al., 1996, Fish & Mills, 1979, Conradi & Depeledge, 1999, McCurdy et al., 2000, Jones and Frid, 2009