| Calanoida | |
|---|---|
 | |
| Unidentified species of copepod in the order Calanoida. | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Copepoda |
| Superorder: | Gymnoplea Giesbrecht, 1882 [1] |
| Order: | Calanoida Sars, 1903 |
| Families | |
See text | |
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. [2]
Calanoids can be distinguished from other planktonic copepods by having first antennae at least half the length of the body and biramous second antennae. [2] However, their most distinctive anatomical trait is the presence of a joint between the fifth and sixth body segments. [3] The largest specimens reach 18 millimetres (0.71 in) long, but most do not exceed 0.5–2.0 mm (0.02–0.08 in) long. [2]
The order Calanoida contains the following families: [4]
Calanoid copepods are the dominant animals in the plankton in many parts of the world's oceans, making up 55–95% of plankton samples. [2] They are therefore important in many food webs, taking in energy from phytoplankton and algae and 'repackaging' it for consumption by higher trophic level predators. [2] Many commercial fish are dependent on calanoid copepods for diet in either their larval or adult forms. Baleen whales such as bowhead whales, sei whales, right whales and fin whales rely substantially on calanoid copepods as a food source. [2]
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 baleen whales.
Zooplankton are the animal component of the planktonic community, having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequently, they 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, puddles, damp moss, or water-filled recesses of plants (phytotelmata) 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.
The basking shark is the second-largest living shark and fish, after the whale shark. It is one of three plankton-eating shark species, along with the whale shark and megamouth shark. Typically, basking sharks reach 7.9 m (26 ft) in length. It is usually greyish-brown, with mottled skin, with the inside of the mouth being white in colour. The caudal fin has a strong lateral keel and a crescent shape. Other common names include bone shark, elephant shark, sailfish, and sunfish. In Orkney, it is called hoe-mother, meaning "the mother of the picked dogfish."
Holoplankton are organisms that are planktic for their entire life cycle. Holoplankton can be contrasted with meroplankton, which are planktic organisms that spend part of their life cycle in the benthic zone. Examples of holoplankton include some diatoms, radiolarians, some dinoflagellates, foraminifera, amphipods, krill, copepods, and salps, as well as some gastropod mollusk species. Holoplankton dwell in the pelagic zone as opposed to the benthic zone. Holoplankton include both phytoplankton and zooplankton and vary in size. The most common plankton are protists.
Harpacticoida is an order of copepods, in the subphylum Crustacea. This order comprises 463 genera and about 3,000 species; its members are benthic copepods found throughout the world in the marine environment and in fresh water. A few of them are planktonic or live in association with other organisms. Harpacticoida represents the second-largest meiofaunal group in marine sediments, after nematodes. In Arctic and Antarctic seas, Harpacticoida are common inhabitants of sea ice. The name Harpacticoida comes from the Greek noun harpacticon and the suffix -oid and means reminiscent of a predator.
The Cyclopoida are an order of small crustaceans from the subclass Copepoda. Like many other copepods, members of Cyclopoida are small, planktonic animals living both in the sea and in freshwater habitats. They are capable of rapid movement. Their larval development is metamorphic, and the embryos are carried in paired or single sacs attached to first abdominal somite.
Diel vertical migration (DVM), also known as diurnal vertical migration, is a pattern of movement used by some organisms, such as copepods, living in the ocean and in lakes. The adjective "diel" comes from Latin: diēs, lit. 'day', and refers to a 24-hour period. The migration occurs when organisms move up to the uppermost layer of the water at night and return to the bottom of the daylight zone of the oceans or to the dense, bottom layer of lakes during the day. DVM is important to the functioning of deep-sea food webs and the biologically-driven sequestration of carbon.
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 1977, and has not been observed since.
Monstrilloida is an order of copepods with a cosmopolitan distribution in the world's oceans. The order contains a single family, Monstrillidae. The name of the first ever described genus Monstrilla is derived from latin, meaning "tiny monster", because the lack of usual diagnostic features of copepods puzzled early taxonomists.
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.
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the order Clupeiformes, but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.
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.
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.
Pleurobrachia pileus is a species of comb jelly, commonly known as a sea gooseberry. It is found in open water in the northern Atlantic Ocean, the North Sea, the Baltic Sea and the Black Sea, and was first described by the Danish zoologist Otto Friedrich Müller in 1776.
Acartia tonsa is a species of marine copepod in the family Acartiidae.
Calanus marshallae is a species of copepod which forms part of the zooplankton in the northern Atlantic Ocean and the northern Pacific Ocean.
Calanus propinquus 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.
Ann Bucklin is Professor Emeritus of Marine Sciences 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.
Media related to Calanoida at Wikimedia Commons
Data related to Calanoida at Wikispecies
