Acartia hudsonica

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Acartia hudsonica
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Subclass: Copepoda
Order: Calanoida
Family: Acartiidae
Genus: Acartia
Species:
A. hudsonica
Binomial name
Acartia hudsonica
Pinhey, 1926

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. [1]

Contents

Acartia hudsonica was originally described as a subspecies of Acartia clausi , but subsequent research [2] concluded it is sufficiently distinct to warrant specific status. It is found in shallow coastal habitats along both the Atlantic and Pacific coasts of northern North America

Anatomy

Acartia hudsonica anatomy is different for the nauplius (larval) stage than the copepodite (juvenile) and adult stages. A nauplius has a head and a tail, but no defined abdominal region. [3] After six stages of molting, a nauplius develops into a copepodite, which now has a distinct abdomen.[ citation needed ] After molting six more times, a copepodite will have grown enough to be considered an adult copepod.[ citation needed ]

An adult copepod is usually under 1 millimeter long. Their bodies are split up into three sections: 1. the head (cephalosome); 2. the abdomen (metasome); and 3. the tail (urosome). The head has a single eye in the center with two pairs of antenna, one long and one short. Copepods also have five pairs of swimming legs that are located on the underside of the abdomen. [4]

An anatomical characteristic that distinguish A. hudsonica from other Acartia species is blue lines on the anterior of their abdomen.

Distribution

Geographic

Like all Acartia species, A. hudsonica is found primarily in estuaries. [5] They can be found in open coastal waters, as well, but they are less abundant in those regions. [6] A. hudsonica is not found farther south than Chesapeake Bay, and is not found farther north than Labrador/Newfoundland. [5]

Temporal

A trait specific to A. hudsonica is that they are only found in cool water. [7] North of Cape Cod, the water stays cold enough throughout the year for A. hudsonica to be abundant year-round. However, south of Cape Cod A. hudsonica is only found in the winter and spring months. This is because the summer and fall months are too warm for the A. hudsonica population to thrive. In response to this temperature increase A. hudsonica has developed a genetic mutation that allows it to lay two different types of eggs: subitaneous and diapause eggs. [8] Subitaneous eggs hatch immediately. Diapause eggs are laid when water temperatures rise above 16˚C and then hatch when exposed to temperatures more typical of winter and spring.

Climate change is affecting the temporal distribution of A. hudsonica in southern estuaries. Temperatures in the winter have warmed more than temperatures in the spring, changing the biologically important threshold for winter-spring species in estuaries. [7] This is causing a population pulse of A. hudsonica to occur about 1.5-2.0 months earlier. [7]

Genetic

It has been found that there are geography distinct subgroups of A. hudsonica along the west Atlantic coast. [1] The first group is from Rhode Island/South Coast Massachusetts/Cape Cod to southern Maine, the second group is from southern Connecticut/Long Island Sound, and the third group is from southern New Jersey. It is thought that the genetic isolation of these subgroups of A. hudsonica has developed because of its geographical isolation in estuaries. [1] This isolation might also contribute to the higher genetic variation within A. hudsonica than other Acartia species.

Ecological significance

Zooplankton play an important role in the pelagic food web by linking primary producers to higher trophic levels, and significantly contribute to biogeochemical cycles. [9] [10] A. hudsonica will feed on a variety of organisms including phytoplankton, heterotrophic protists and mixotrophic protists. The energy gained from their prey then gets transferred up the food web when the A. hudsonica themselves are eaten. [11] A literature review done in 1984 showed that copepods, including Acartia, are the most frequently recorded prey of larval fish. [12] And subsequent research has continued to document this trend. [13]

With the changing climate the size of estuarine copepods, such as A. hudsonica, are decreasing, which could disrupt the predator-prey interaction that commonly occurs between fish larvae (predators) and copepods (prey). [9] If the dynamic of this interaction changes then the community structure and ecological function of estuaries could be altered.

Related Research Articles

<span class="mw-page-title-main">Copepod</span> Subclass of crustaceans

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.

<span class="mw-page-title-main">Spring bloom</span> Strong increase in phytoplankton abundance that typically occurs in the early spring

The spring bloom is a strong increase in phytoplankton abundance that typically occurs in the early spring and lasts until late spring or early summer. This seasonal event is characteristic of temperate North Atlantic, sub-polar, and coastal waters. Phytoplankton blooms occur when growth exceeds losses, however there is no universally accepted definition of the magnitude of change or the threshold of abundance that constitutes a bloom. The magnitude, spatial extent and duration of a bloom depends on a variety of abiotic and biotic factors. Abiotic factors include light availability, nutrients, temperature, and physical processes that influence light availability, and biotic factors include grazing, viral lysis, and phytoplankton physiology. The factors that lead to bloom initiation are still actively debated.

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.

<span class="mw-page-title-main">Ecology of the San Francisco Estuary</span>

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.

<i>Acartia</i> Genus of crustaceans

Acartia is a genus of marine calanoid copepods. They are epipelagic, estuarine, zooplanktonic found throughout the oceans of the world, primarily in temperate regions.

<i>Acartia clausi</i> Species of crustacean

Acartia clausi is a species of marine copepod belonging to the family Acartiidae. This species was previously thought to have a worldwide distribution but recent research has restricted its range to coastal regions of the north-eastern Atlantic Ocean as far north as Iceland, the Mediterranean Sea and the Black Sea, with specimens from other regions assigned to different species.

Acartia lefevreae 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. Its range overlaps with that of A. clausi, being found in the western Mediterranean and the north east Atlantic as far north as the English Channel, but it tends to be found in more brackish habitats such as estuaries.

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 omorii is a species of marine 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 is found around the coast of Japan. It is similar to A. clausi but lacks the prominent spines on the dorsal part of the posterior body segment (metasome).

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.

Acartia jilletti is a species of marine copepod belonging to the family Acartiidae. This species has a total length of up to 1 mm. It is very similar to Acartia ensifera but the female can be distinguished by the shorter caudal rami and the male by the relative length of spines on the fifth pair of legs. This species has been recorded from scattered locations around the coast of New Zealand.

Acartia tranteri is a species of marine copepod belonging to the family Acartiidae. This Australian species is related to the New Zealand species A. ensifera, A. jilletti and A. simplex but can be distinguished by the lack of any ventral prominence posterior to the genital opening in the female and the presence of posterior spines on the metasome of the male. It is found off the southern coast of Australia.

Acartia tonsa is a species of marine copepod in the family Acartiidae.

Calanus propinquus is a copepod found in Antarctica, and the surrounding waters.

<i>Calanoides acutus</i> Species of crustacean

Calanoides acutus is a copepod found in Antarctica and the surrounding waters.

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.

Calanus sinicus is a copepod found in the northwest Pacific.

<i>Paracalanus parvus</i> Species of crustacean

Paracalanus parvus is a copepod found throughout the world, except the Arctic.

Pseudocalanus minutus is a small copepod found in the Arctic Ocean and surrounding waters.

References

  1. 1 2 3 Milligan, Peter J.; Stahl, Eli A.; Schizas, Nikolaos V.; Turner, Jefferson T. (2011). "Phylogeography of the copepod Acartia hudsonica in estuaries of the northeastern United States". Hydrobiologia. 666: 155–165. doi:10.1007/s10750-010-0097-y. S2CID   39802823.
  2. ↑ Bradford, Janet (1976). "Partial Revision of the Acartia Subgenus Acartiura (Copepoda: Calanoida: Acartiidae)". New Zealand Journal of Marine and Freshwater Research. 10 (1): 159–202. doi: 10.1080/00288330.1976.9515606 .
  3. ↑ "Copepod: Definition, Characteristics and Lifecycle". Biologydictionary.net. 11 February 2018.
  4. ↑ "Copepod Printout". Enchantedlearning.com.
  5. 1 2 Lee, Wen Yuh; McAlice, B. J. (1979). "Seasonal Succession and Breeding Cycles of Three Species of Acartia (Copepoda: Calanoida) in a Maine Estuary". Estuaries. 2 (4): 228. doi:10.2307/1351569. JSTOR   1351569. S2CID   84666406.
  6. ↑ Turner, Jefferson T. (1994). "Planktonic copepods of Boston Harbor, Massachusetts Bay and Cape Cod Bay, 1992". Ecology and Morphology of Copepods. pp. 405–413. doi:10.1007/978-94-017-1347-4_51. ISBN   978-90-481-4490-7.
  7. 1 2 3 Sullivan, Barbara K.; Costello, John H.; Van Keuren, D. (2007). "Seasonality of the copepods Acartia hudsonica and Acartia tonsa in Narragansett Bay, RI, USA during a period of climate change". Estuarine, Coastal and Shelf Science. 73 (1–2): 259–267. Bibcode:2007ECSS...73..259S. doi:10.1016/j.ecss.2007.01.018.
  8. ↑ Barbara K. Sullivan; Liana T. McManus (1986). "Factors controlling seasonal succession of the copepods Acartia hudsonica and A. tonsa in Narragansett Bay, Rhode Island: temperature and resting egg production" (PDF). Marine Ecology Progress Series. 28: 121–128. Bibcode:1986MEPS...28..121S. doi:10.3354/meps028121 . Retrieved 7 March 2022.
  9. 1 2 Rice, Edward; Dam, Hans G.; Stewart, Gillian (2015). "Impact of Climate Change on Estuarine Zooplankton: Surface Water Warming in Long Island Sound is Associated with Changes in Copepod Size and Community Structure". Estuaries and Coasts. 38: 13–23. doi:10.1007/s12237-014-9770-0. S2CID   83969838.
  10. ↑ Dam, Hans G.; Roman, Michael R.; Youngbluth, Marsh J. (1995). "Downward export of respiratory carbon and dissolved inorganic nitrogen by diel-migrant mesozooplankton at the JGOFS Bermuda time-series station". Deep Sea Research Part I: Oceanographic Research Papers. 42 (7): 1187–1197. Bibcode:1995DSRI...42.1187D. doi:10.1016/0967-0637(95)00048-B.
  11. ↑ Cristian A. Vargas; Humberto E. González (2004). "Plankton community structure and carbon cycling in a coastal upwelling system. II. Microheterotrophic pathway" (PDF). Aquatic Microbial Ecology. 34: 165–180. doi:10.3354/ame034165 . Retrieved 7 March 2022.
  12. ↑ "Welcome to AquaDocs". Aquadocs.org. Retrieved 7 March 2022.
  13. ↑ Jefferson T. Turner (2004). "The Importance of Small Planktonic Copepods and Their Roles in Pelagic Marine Food Webs" (PDF). Zoological Studies. 43 (2): 255–266. Retrieved 7 March 2022.
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