Phytoplankton are usually photosynthetic one-celled plant organisms. These organisms are usually found near the surface of the water due to their need for light energy for their photosynthetic processes. Phytoplankton provide most of the oxygen that is in the water and provide a large amount of food for other organisms in the water column.
Planktivores ingest one or both types of plankton. Titanichthys was the first massive vertebrate pelagic planktivore, with a lifestyle similar to that of the modern basking, whale, or megamouth sharks.
Most fish are planktivores during part or all of their life cycles, especially when they are larvae. There are obligate planktivores, which feed only on plankton, and facultative planktivores, which take plankton when available but eat other types of food as well. The gizzard shad (Dorosoma cepedianum), for example, has a voracious appetite for various forms of plankton across its life cycle. It is an obligate planktivore when it is a juvenile, in part due to its very small mouth size. As it grows it becomes an omnivore, taking phytoplankton, zooplankton, and larger pieces of nutritious detritus. Adult gizzard shad consume large volumes of zooplankton until it becomes scarce, then turn to organic debris for food.
Planktivores obtain food in two ways. Particulate feeders eat planktonic items selectively. Filter feeders process volumes of water and strain food items en masse. "Tow-net" filter feeders swim rapidly with mouths open to filter the water, and pumping filter feeders suck in water via pumping actions. The latter includes stationary animals, such as corals. Another form of filter feeding is a "gulping" behavior, in which the animal takes boluses of water; the alewife (Alosa pseudoharengus) feeds in this manner.
Plankton are among the lower trophic levels in food chains. Planktivores affect the food chain by altering the populations of plankton in various ways, a process known as the trophic cascade. The gizzard shad, again, plays this role. It consumes phytoplankton when it is small, zooplankton when it is larger, and other foods when it eliminates the zooplankton in the area. It incidentally controls the populations of other fish that depend on zooplankton, such as bluegill (Lepomis macrochiris).
The ariakehimeshirauo, Neosalanx reganius, is a species of icefish in the Salangidae family endemic to Japan. It is only known from Midori and Chikugo Rivers in Kyushu. Its maximum total length is 63 mm (2.5 in), and has a lifespan of about one year. It seems to be relatively rare in its limited habitat, and is classified as a vulnerable species by IUCN.N. reganius is an estuarine species, usually found in turbid waters with low salinity, or in fresh water. It is a planktivore. Relative to its size, it is highly fecund (347–1071 eggs per female), and the ovaries of gravid females made up 44% of their total body weight, on average.Avivore
An avivore is a specialized predator of birds, with birds making up a large proportion of its diet. Such bird-eating animals come from a range of groups.Bacterivore
Bacterivores are free-living, generally heterotrophic organisms, exclusively microscopic, which obtain energy and nutrients primarily or entirely from the consumption of bacteria. Many species of amoeba are bacterivores, as well as other types of protozoans. Commonly, all species of bacteria will be prey, but spores of some species, such as Clostridium perfringens, will never be prey, because of their cellular attributes.Decomposer
Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development. While the terms decomposer and detritivore are often interchangeably used, detritivores must ingest and digest dead matter via internal processes while decomposers can directly absorb nutrients through chemical and biological processes hence breaking down matter without ingesting it. Thus, invertebrates such as earthworms, woodlice, and sea cucumbers are technically detritivores, not decomposers, since they must ingest nutrients and are unable to absorb them externally.Dinichthyloidea
The Dinichthyloidea is an extinct superfamily of placoderms, armored fish most diverse during the Devonian. They contain numerous extremely large species, such as Titanichthys, presumed to be a planktivore, the apex predator Dinichthys, as well as numerous other genera of diverse size and habits, such as the tiny Rhachiosteus, the superficially tuna-like Bungartius, and the selenosteids and trematosteids.Filter feeder
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms.Florivore
In zoology, a florivore (not to be confused with a folivore) is an animal which mainly eats products of flowers. Florivores are types of herbivores (often referred to as floral herbivores), yet within the feeding behaviour of florivory, there are a range of other more specific feeding behaviours, including, but not limited to:
Granivory: the consumption of grain and seeds
Nectarivory: the consumption of flower nectar
Palynivory: the consumption of flower pollen
Frugivory: the consumption of fruitFolivore
In zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds. For this reason, folivorous animals tend to have long digestive tracts and slow metabolisms. Many enlist the help of symbiotic bacteria to release the nutrients in their diet. Additionally, as has been observed in folivorous primates, they exhibit a strong preference towards immature leaves, which tend to be easier to masticate, tend to be higher in energy and protein, and lower in fibre and poisons than more mature fibrous leaves.Gymnocypris przewalskii
Gymnocypris przewalskii (common name: Przewalskii's naked carp; in Chinese: 青海湖裸鲤; literally: 'Qinghai Lake naked carp') is a species of cyprinid that is endemic to the Lake Qinghai basin in China, where it is the dominant fish species (the other natives are four Triplophysa loaches). G. przewalskii is a planktivore with a main population that migrates from the lake to rivers to spawn and another that lives its entire life in the nearby Ganzi River. The species is listed as endangered on the China Species Red List due to overfishing and habitat loss, which has led to suspension of its commercial fishery four times since 1989.Mesocarnivore
A mesocarnivore is an animal whose diet consists of 30–70% meat with the balance consisting of non-animal foods which may include fungi, fruits, and other plant material. Mesocarnivores are seen today among the Canidae (coyotes, foxes), Viverridae (civets), Mustelidae (martens, tayra), Procyonidae (ringtail, raccoon), Mephitidae (skunks), and Herpestidae (some mongooses).Midas blenny
Ecsenius midas, known commonly as the Midas blenny, Persian blenny, lyretail blenny or golden blenny, is a species of marine fish in the family Blenniidae.The Midas blenny is widespread throughout the tropical waters of the Indo-Pacific area from the eastern coast of Africa, Red Sea included, to the Marquesan Islands. The specific name references the Phrygian king Midas who , in Greek mythology turned all he touched into gold, the type was a golden color in life although it is now known that this species is variable in color.It grows to a size of 13 cm in length.
Its normal color is golden orange but it can adapt its color (mimicry) to match the color of the fishes it mixes with. It shows a black spot near the anus. It is often seen in company of the lyretail anthias (Pseudanthias squamipinnis).The Midas blenny is a planktivore.It occasionally makes its way into the aquarium trade.Monodactylus argenteus
Monodactylus argenteus is a species of fish in the family Monodactylidae, the moonyfishes. Its common names include silver moonyfish, or silver moony, butter bream, and diamondfish. It is native to the western Pacific and Indian Oceans, including the Persian Gulf, Red Sea, and associated estuaries, such as the Mekong Delta.This species reaches a maximum length of about 27 centimeters. It is bright shiny silver with yellowish edges to the fins. The dorsal and anal fins have black tips. Juveniles have more yellow coloration and are distinguished by two vertical black bands.
This species occurs in a wide variety of habitat types, including the open ocean, brackish waters, and the freshwater habitat of rivers. In Australia it can be found in harbors and estuaries around piers. Its ability to survive in a wide range of salinities makes it a model organism in the study of salinity tolerance. Juveniles are especially tolerant to salinity changes, easily maintaining homeostasis in variable environments such as estuaries.Although the silver moony displays territorial behavior, the species can be kept in saltwater aquaria and is easy to rear in captivity. It can remain solitary or form schools. It is a detritivore and planktivore.
The myxozoan parasite Kudoa monodactyli was first described from and named after this fish.Mucophagy
Mucophagy (literally "mucus feeding") is feeding on mucus of fishes or invertebrates. It may also refer to consumption of mucus or dried mucus in primates.
There are mucophagous parasites, such as some sea lice that attach themselves to gill segments of fish.Mucophages may serve as cleaners of other animals.
Another usage of this term is in reference to the feeding organ rich in mucous cells which pumps the water through, feeding particles get entrapped in mucus, and the latter proceeds into the esophagus.Ohmdenia
Ohmdenia is an extinct genus of prehistoric bony fish that lived from the Toarcian stage of the Early Jurassic epoch.Ohmdenia was first described in 1953 by B. Hauff, based on a fossil found in the well-known schists at Posidonia in Holzmaden, Germany. For a long time this animal has been considered a close relative of Birgeria, a great predator typical of the Triassic period with an uncertain systematic position . Further studies have shown similarities with the pachicormiforms, a group of neopolitics considered close to the origin of teleosts and also including giant forms and planctives (e.g. Leedsichthys). Some studies have erroneously indicated Ohmdenia as a synonym of Saurostomus, other studies have instead placed Ohmdenia as an important evolutionary passage between the basal pachicormiforms and the more derived planktivore pachicormiformes.Paedophagy
Paedophagy (literally meaning the "consumption of children") in its general form is the feeding behaviour of fish or other animals whose diet is partially, or primarily the eggs or larvae of other animals. However, P. H. Greenwood, who was the first to describe paedophagia, defines it to be a feeding behaviour evolved among cichlid fishes.Pambdelurion
Pambdelurion whittingtoni is an extinct, blind, nektonic organism from the Sirius Passet Lagerstätte, from Cambrian Greenland. Its anatomy strongly suggests that it, along with its relative Kerygmachela kierkegaardi, was either an anomalocarid or a close relative thereof.P. whittingtoni had a pair of massive anterior limbs that corresponded to the feeding limbs of other anomalocarids. The anterior limbs had a row of flexible, hair-like spines that corresponded with each segment of each limb. Unlike K. kierkegaardi, P. whittingtoni's mouth was relatively large, though it does not appear to have any large biting surfaces like the mouth of Anomalocaris. It had 11 pairs of lateral lobes, and 11 pairs of relatively large, lobopod-like legs. None of the fossil specimens have any suggestion of posterior cerci, or tail-flaps.
The massive anterior limbs, with their comb-like rows of spines, suggest that P. whittingtoni was a planktivore.Saprophagy
Saprophages are organisms that obtain nutrients by consuming decomposing dead plant or animal biomass. They are distinguished from detritivores in that saprophages are sessile consumers while detritivore are mobile. Typical saprophagic animals include sedentary polychaetes such as amphitrites (Amphitritinae, worms of the family Terebellidae) and other terebellids.
The eating of wood, whether live or dead, is known as xylophagy. Τhe activity of animals feeding only on dead wood is called sapro-xylophagy and those animals, sapro-xylophagous.Serranus tortugarum
The chalk bass (Serranus tortugarum) is a species of bass fish from warm parts of the Western Atlantic, including the Caribbean, the Bahamas and southern Florida, that occasionally makes its way into the aquarium trade. This planktivore is found at depths of 12 to 369 m (39–1,211 ft) and grows to a total length of 8 cm (3.1 in).Zooplankton
Zooplankton (, ) are heterotrophic (sometimes detritivorous) plankton (cf. phytoplankton). Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word zooplankton is derived from the Greek zoon (ζῴον), meaning "animal", and planktos (πλαγκτός), meaning "wanderer" or "drifter". Individual zooplankton are usually microscopic, but some (such as jellyfish) are larger and visible to the naked eye.