Metaphoetesis is an ecological term coined by G. E. Hutchinson, [1] to denote a change in diet with a changing stage of the life cycle of an animal. This characteristic, exhibited by many species such as insects and fishes, is important in determining the length of a food chain, particularly in aquatic and amphibious environments. Smaller, i.e., younger specimens belong to foodchain links below the larger -older- specimens. [2] The concept has been described by other authors using various terms such as "life history omnivory". [3]
For instance, lake trout, Salvelinus namaycush Walbaum, 1792 Salmonidae , a Holoarctic freshwater fish species, exhibit different growth patterns within a single lake at a given time and among ensembles of similar lake types. These growth patterns are related to the species' food habits, and have consequences in growth rate, age at maturity, etc. Small, fast-growing, precocious adult trouts are planktivores, and inhabit lakes that are devoid of fish prey, while large, slow-growing, delayed maturation trouts are piscivores and inhabit lakes where fish prey is abundant (Kerr, 1979). [4]
A more recent article, not related to metaphoetesis per se, associates the reduction of lake trout populations in North American and European lakes to acid rain which wiped out the populations of Mysis species ( Mysis relicta and Mysis salemaai in Europe and Mysis diluviana in North America). These are rather large (ca. 2.5 cm long) benthopelagic crustaceans that thrive in oligotrophic, well-oxygenated waters, precisely the habitat of lake trout. [5] No reference is made to whether these trout populations are intermediate in size and maturation age between the planktivore and the piscivore.
Trout is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera Oncorhynchus, Salmo and Salvelinus, all of which are members of the subfamily Salmoninae in the family Salmonidae. The word trout is also used for some similar-shaped but non-salmonid fish, such as the spotted seatrout/speckled trout.
The lake trout is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, namaycush,lake char (or charr), touladi, togue, and grey trout. In Lake Superior, it can also be variously known as siscowet, paperbelly and lean. The lake trout is prized both as a game fish and as a food fish. Those caught with dark coloration may be called mud hens.
Tilapia is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes, with the economically most important species placed in the Coptodonini and Oreochromini. Tilapia are mainly freshwater fish inhabiting shallow streams, ponds, rivers, and lakes, and less commonly found living in brackish water. Historically, they have been of major importance in artisanal fishing in Africa, and they are of increasing importance in aquaculture and aquaponics. Tilapia can become a problematic invasive species in new warm-water habitats such as Australia, whether deliberately or accidentally introduced, but generally not in temperate climates due to their inability to survive in cold water.
This glossary of ecology is a list of definitions of terms and concepts in ecology and related fields. For more specific definitions from other glossaries related to ecology, see Glossary of biology, Glossary of evolutionary biology, and Glossary of environmental science.
The brown trout is a species of salmonid ray-finned fish and the most widely distributed species of the genus Salmo, endemic to most of Europe, West Asia and parts of North Africa, and has been widely introduced globally as a game fish, even becoming one of the world's worst invasive species outside of its native range.
The rainbow trout is a species of trout native to cold-water tributaries of the Pacific Ocean in North America and Asia. The steelhead is an anadromous (sea-run) form of the coastal rainbow trout(O. m. irideus) or Columbia River redband trout (O. m. gairdneri) that usually returns to freshwater to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead.
The brook trout is a species of freshwater fish in the char genus Salvelinus of the salmon family Salmonidae native to Eastern North America in the United States and Canada. Two ecological forms of brook trout have been recognized by the US Forest Service. One ecological form is short-lived potamodromous populations in Lake Superior known as coaster trout or coasters. The second ecological form is the long-living predaceous anadromous populations which are found in northern lakes and coastal rivers from Long Island to Hudson Bay, which are referred to as salters. In parts of its range, it is also known as the eastern brook trout, speckled trout, brook char, squaretail, brookie, or mud trout, among others. Adult coaster brook trout are capable of reaching sizes over 2 feet in length and weigh up to 6.8 kg (15 lb), whereas adult salters average between 6 and 15 inches in length and weigh between 0.5 and 2.3 kg. The brook trout is characterized by its distinctive olive-green body with yellow and blue-rimmed red spots, white and black edged orange fins, and dorsal vermiculation. The diet of the brook trout is restrictive to the season and location of the fish, but will typically consist of terrestrial and aquatic insects, fry, crustaceans, zooplankton, and worms.
Flathead Lake is a large natural lake in northwest Montana, United States.
Broodstock, or broodfish, are a group of mature individuals used in aquaculture for breeding purposes. Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers. These are generally kept in ponds or tanks in which environmental conditions such as photoperiod, temperature and pH are controlled. Such populations often undergo conditioning to ensure maximum fry output. Broodstock can also be sourced from wild populations where they are harvested and held in maturation tanks before their seed is collected for grow-out to market size or the juveniles returned to the sea to supplement natural populations. This method, however, is subject to environmental conditions and can be unreliable seasonally, or annually. Broodstock management can improve seed quality and number through enhanced gonadal development and fecundity.
The round whitefish is a freshwater species of fish that is found in North American drainages from Alaska to New England, including the Great Lakes except for Lake Erie, and in Arctic tributaries of northeast Asia, as well as northern Kamchatka Peninsula and the northern coasts of the Sea of Okhotsk. It has an olive-brown back with light silvery sides and underside and its length is generally between 9 and 19 inches. They are bottom feeders, feeding mostly on invertebrates, such as crustaceans, insect larvae, and fish eggs. Some other fish species, like white sucker in turn eat their eggs. Lake trout, northern pike and burbot are natural predators. Other common names of the round whitefish are Menominee, pilot fish, frost fish, round-fish, and Menominee whitefish. The common name "round whitefish" is also sometimes used to describe Coregonus huntsmani, a salmonid more commonly known as the Atlantic whitefish.
The rainbow smelt is a North American species of fish of the family Osmeridae. Walleye, trout, and other larger fish prey on these smelt. The rainbow smelt prefer juvenile ciscoes, zooplankton such as calanoid copepods, and other small organisms, but are aggressive and will eat almost any fish they find. They are anadromous spring spawners and prefer clean streams with light flow and light siltation. The rainbow smelt face several barriers. They are weak swimmers and struggle to navigate fish ladders preventing them from making it past dams to the headwater streams where they spawn. The rise in erosion and dams helped to decimate the smelt population in the 1980s. There are currently plans to try to reduce damming and to help control erosion.
A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems, which include ponds, lakes and wetlands, and much of this article applies to lentic ecosystems in general. Lentic ecosystems can be compared with lotic ecosystems, which involve flowing terrestrial waters such as rivers and streams. Together, these two ecosystems are examples of freshwater ecosystems.
Coregonus hoyi, also known as the bloater, is a species or form of freshwater whitefish in the family Salmonidae. It is a silvery-coloured herring-like fish, 25.5 centimetres (10.0 in) long. It is found in most of the Great Lakes and in Lake Nipigon, and inhabits underwater slopes. This fish is not to be confused with the extinct deepwater cisco, a large fish that shared a common name with the bloater.
The common river galaxias or Canterbury galaxias is a galaxiid fish of the genus Galaxias, found only in Canterbury, New Zealand.
A piscivore is a carnivorous animal that primarily eats fish. The name piscivore is derived from Latin piscis 'fish', and vorō 'to devour'. Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evolution ; insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory.
Fathead minnow, also known as fathead or tuffy, is a species of temperate freshwater fish belonging to the genus Pimephales of the cyprinid family. The natural geographic range extends throughout much of North America, from central Canada south along the Rockies to Texas, and east to Virginia and the Northeastern United States. This minnow has also been introduced to many other areas via bait bucket releases. Its golden, or xanthic, strain, known as the rosy-red minnow, is a very common feeder fish sold in the United States and Canada. This fish is best known for producing Schreckstoff.
Mysis relicta is a shrimp-like crustacean in the Mysida order, native to lakes of Northern Europe and to the brackish Baltic Sea.
Consumer–resource interactions are the core motif of ecological food chains or food webs, and are an umbrella term for a variety of more specialized types of biological species interactions including prey-predator, host-parasite, plant-herbivore and victim-exploiter systems. These kinds of interactions have been studied and modeled by population ecologists for nearly a century. Species at the bottom of the food chain, such as algae and other autotrophs, consume non-biological resources, such as minerals and nutrients of various kinds, and they derive their energy from light (photons) or chemical sources. Species higher up in the food chain survive by consuming other species and can be classified by what they eat and how they obtain or find their food.
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.
Since the recession of the last glaciation, isolated bodies of water high in mountain crevasses have been topographically separated from fish. Within Washington state a number of lakes in the Olympic and Cascade Mountains have been stocked since the early 20th century. Prior to the existence of a state wildlife management agency, the U.S. Forest Service stocked mountain lakes with rainbow trout, cutthroat trout and eastern brook trout. High lake management of this era largely focused on improving sport fishing opportunities and secondarily establishing ecological balance. Natural reproduction of fish species, especially eastern brook trout, has led to overpopulation and “stunting” from starvation in low nutrient environments. The result has been decreased interest from fishermen, while causing large, negative impacts on natural lake biota. Addressing concerns for biodiversity can positively impact agendas for the conservation of species, as well as high lakes fishery management.