The Atlantic silverside (''Menidia menidia''), also known as spearing in the northeastern United States, is a small species of fish from the West Atlantic, ranging from the
Gulf of St. Lawrence in Canada to northeastern
Florida
Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
in the USA. It is one of the most common fish in the
Chesapeake Bay
The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the Eastern Shore of Maryland / ...
and in the
Barnegat Bay
Barnegat Bay is a small brackish arm of the Atlantic Ocean, approximately long, along the coast of Ocean County, New Jersey in the United States. It is separated from the Atlantic by the long Island Beach State Park (colloquially called a "ba ...
. It is a common subject of scientific research because of its sensitivity to environmental changes.
The fish is about long, mostly silver and white. It eats smaller (biotic) animals and plants – small
crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...
s,
alga
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
e,
annelid worms,
shrimp,
zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...
,
copepods,
amphipods,
squid, and
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...
s.
The Atlantic silverside's predators are larger predatory fish –
striped bass,
blue fish
The bluefish (''Pomatomus saltatrix'') is the only extant species of the family Pomatomidae. It is a marine pelagic fish found around the world in temperate and subtropical waters, except for the northern Pacific Ocean. Bluefish are known as ta ...
,
Atlantic mackerel
The Atlantic mackerel (''Scomber scombrus''), also known as Boston mackerel, Norwegian mackerel, Scottish mackerel or just mackerel, is a species of mackerel found in the temperate waters of the Mediterranean Sea, the Black Sea, and the northern ...
– and many water birds, including
egrets
Egrets ( ) are herons, generally long-legged wading birds, that have white or buff plumage, developing fine plumes (usually milky white) during the breeding season. Egrets are not a biologically distinct group from herons and have the same build ...
,
terns
Terns are seabirds in the family Laridae that have a worldwide distribution and are normally found near the sea, rivers, or wetlands. Terns are treated as a subgroup of the family Laridae which includes gulls and skimmers and consists of ...
,
cormorants
Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the IOC adopted a consensus taxonomy of seven gen ...
, and
gulls
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari (bird), Lari. They are most closely related to the terns and Skimmer (bird), skimmers and only distantly related to auks, and even more distantly to waders ...
.
The abiotic factors the Atlantic silverside needs to survive varies for populations of fish based on their geographical location. A rule of thumb for the species includes an average temperature of , a salt content of the water ranging from 0 to 37ppt (Tagatz and Dudley 1961), and a well-mixed body of water to prevent
hypoxic
Hypoxia means a lower than normal level of oxygen, and may refer to:
Reduced or insufficient oxygen
* Hypoxia (environmental), abnormally low oxygen content of the specific environment
* Hypoxia (medical), abnormally low level of oxygen in the t ...
conditions.
The Atlantic silverside's habitat is generally near the water's edge. They are mostly found swimming in
brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estu ...
waters, such as in the mouths of rivers and streams that connect to the ocean. These small schooling fish have been seen to gather in
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the or ...
beds, which can harbor the nearly defenseless fish some form of shelter from predation as well as provide safe haven for spawning. During winter, most Atlantic silversides swim in deeper water to avoid cold/low temperature. During the summer, most are found in the shallows along the shoreline.
The Atlantic silverside's defense is to hide in seagrass beds. They are also quick swimmers and their coloration of silver and a little white makes it confusing to predators to determine the direction the fish are heading. The silverside's strongest form of defense is the strength-in-numbers strategy, where fish will school in large numbers to diminish their chances of being the one picked off by a predator.
References
* Tagatz, M. E., and D. L. Dudley. 1961. Seasonal occurrence of marine fishes in four shore habitats near Beaufort, North Carolina, 1957-1960. U. S. Fish Wildl. Serv. Spec. Sci. Rep. Fish. 390. 19 pp.
External links
Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic): Atlantic SilversideInland Silverside, ''Menidia beryllina'', Photo and Information at MBL Aquaculture
{{DEFAULTSORT:Atlantic Silverside
Atherinopsidae
Fish described in 1766
Taxa named by Carl Linnaeus