| Acartia tonsa | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Crustacea |
| Subclass: | Copepoda |
| Order: | Calanoida |
| Family: | Acartiidae |
| Genus: | Acartia |
| Species: | A. tonsa |
| Binomial name | |
| Acartia tonsa Dana, 1849 | |
| Synonyms | |
| |
Acartia tonsa is a species of marine copepod in the family Acartiidae. [1]
Acartia tonsa is a species of calanoid copepod that can be found in a large portion of the world's estuaries and areas of upwelling where food concentrations are high. [2] [3]
Like many plankton common to estuarine ecosystems, they can live in a wide range of temperatures and salinities. [2] The wide distribution of Acartia tonsa may be a result of these copepods being transported as ballast in ships. Their tolerance to changes in salinity has likely contributed to their success as an invasive species in some regions. [4]
Acartia tonsa is translucent, [5] and is usually between about .8 and 1.5 millimetres (0.031 and 0.059 in) in length in females, and from about .8 to 1.3 millimetres (0.031 to 0.051 in) in males. [6] It "[c]an be differentiated from closely related species by their long first antennae (at least half the length of their bodies) and biramous (branched) second antennae, as well as the presence of a joint between their fifth and sixth body segments". [5]
In estuaries and coastal waters which are warm throughout the year, A. tonsa is found year-round. In cooler climates including the North Atlantic, it is frequently the dominant zooplankton in the spring and summer. Acartia tonsa produces eggs in the winter in colder geographic regions. The eggs hatch when temperatures exceed 15 °C (59 °F). [7] [8]
They are an important food source for many commercial fish species. [8] Several studies indicate they aggregate near the ocean floor during the day and rise closer to the surface at night. This behavior likely helps A. tonsa avoid predators who rely on vision to locate and capture prey. [9]
A. tonsa nauplii and adults feed on phytoplankton as well as planktonic ciliates and rotifers. [10] It acts as a suspension feeder when feeding on phytoplankton. When feeding on motile prey it acts as an ambush feeder; it stays nearly motionless in the water, detects movement of its prey, and then jumps toward the prey. Moderate amounts of turbulence improve rates of ambush feedings. [11]
Plankton are the diverse collection of organisms found in water that are unable to propel themselves against a current. The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales.
Zooplankton are the animal component of the planktonic community. Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers.
Copepods are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic, some are benthic, a number of species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses (phytotelmata) of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as biodiversity indicators.
Calanoida is an order of copepods, a group of arthropods commonly found as zooplankton. The order includes around 46 families with about 1800 species of both marine and freshwater copepods between them.
Hemiboeckella powellensis, is a zooplankton copepod of which only four of its kind have ever been observed. "Hemiboeckella" refers to this genus being a subvariant of Boeckella, whilst “powellensis” refers to Lake Powell in Western Australia, the region it is endemic to. Its existence was initially recorded in May and June of 1977, and has not been observed since.
Calanus finmarchicus is a species of copepods and a part of zooplankton, which is found in enormous amounts in the northern Atlantic Ocean.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
Acartia is a genus of marine calanoid copepods. They are epipelagic, estuarine, zooplanktonic found throughout the oceans of the world, primarily in temperate regions.
Acartia teclae is a species of copepod belonging to the family Acartiidae. This species was discovered when specimens previously identified as Acartia clausi were examined and found to belong to a separate species. This species appears to have a similar range to, and occupies similar brackish estuarine habitats as, Acartia lefevreae but differs in the absence of spines on the dorsal part of the posterior body segment (metasome).
Acartia hudsonica is a species of marine copepod belonging to the family Acartiidae. Acartia hudsonica is a coastal, cold water species that can be found along the northwest Atlantic coast.
Acartia ensifera is a species of marine copepod belonging to the family Acartiidae. This is a slender copepod, around 0.8–0.9 mm (0.031–0.035 in) in length, with distinctively long caudal rami. It is found around the coasts of New Zealand.
Acartia simplex is a species of marine copepod belonging to the family Acartiidae. This species, just under 1 mm in length, is rather similar to Acartia ensifera but can be distinguished by the presence of spines on the dorsal part of the posterior body segment (metasome). Like A. ensifera, it is found around the coasts of New Zealand, mainly in estuarine habitats.
A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and in the past billion years; basking sharks and copepods are just two examples of giant and microscopic organisms that feed upon plankton. Planktivory can be an important mechanism of top-down control that contributes to trophic cascades in aquatic and marine systems. There is a tremendous diversity of feeding strategies and behaviors that planktivores utilize to capture prey. Some planktivores utilize tides and currents to migrate between estuaries and coastal waters; other aquatic planktivores reside in lakes or reservoirs where diverse assemblages of plankton are present, or migrate vertically in the water column searching for prey. Planktivore populations can impact the abundance and community composition of planktonic species through their predation pressure, and planktivore migrations facilitate nutrient transport between benthic and pelagic habitats.
Oxyrrhis marina is a species of dinoflagellates with flagella. A marine heterotroph, it is found in much of the world.
Calanoides acutus is a copepod found in Antarctica and the surrounding waters.
Neocalanus plumchrus is a large species of copepod found in the Pacific and Arctic Oceans. It was described in 1921 by Marukawa. N. flemingeri was formerly considered as conspecific, likely as a form, until it was split in 1988 by Charles B. Miller.
Pseudocalanus newmani is a copepod found in Arctic and northern Pacific waters. It was described by Frost in 1989. It is found in the Arctic and surrounding waters. There are multiple generations. Unlike some copepods, P. newmani undergoes reverse diel vertical migration, descending during the night, and ascending during the day, although it may undergo normal or no migration at all depending on predation. This copepod is primarily herbivorous.
Metridia gerlachei is a copepod found primarily in Antarctic and sub-Antarctic waters.
Pseudocalanus minutus is a small copepod found in the Arctic Ocean and surrounding waters.
Ann Bucklin is a professor at the University of Connecticut known for her work using molecular tools to study zooplankton. Bucklin was elected a fellow of the American Association for the Advancement of Science in 1995.
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