Composition, Abundance, and Life History of Mysids (Crustacea: Mysida) in the Coastal Lagoons of MD, USA

The composition, abundance, biomass, and life history of mysid species were investigated and described for the first time in the Maryland Coastal Bays (38A degrees N, 75A degrees W), Mid-Western Atlantic, using data collected from 2010 to 2013. Three species of mysids were collected, with Neomysis americana being the most abundant species (maximum mean abundance 6.7 +/- 6.4 numbers (nos.) m(-2) in July 2013 and biomass 2.78 +/- 2.76-mg dry weight (DW) m(-2) in July 2012). Americamysis bahia was the second most abundant species (maximum mean abundance: 0.7 +/- 0.4 nos. m(-2) and biomass: 0.23 +/- 0.14 mg DW m(-2) in March 2012). Metamysidopsis swifti made up 0.02 to 2 % of mysids and were found in samples collected mainly from southern Chincoteague Bay close to that Bay's inlet in the fall of 2012. The two most abundant mysid species reproduced continuously from March to July (Neomysis) and May to October (Americamysis). N. americana had larger body and brood sizes than A. bahia. Mysids were relatively low in abundance in late summer, a period of relatively high biomass of fish predators, than during other seasons, suggesting that intense predation might be controlling their abundance. The increase in mysid abundance in the fall following their disappearance in late summer without evidence of reproductive activities suggests species migration from coastal waters into the Maryland Coastal Bays. This annual mysid subsidy perhaps helps to sustain their populations within the bays.