| Alaska blackfish | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Esociformes |
| Family: | Esocidae |
| Genus: | Dallia |
| Species: | D. pectoralis |
| Binomial name | |
| Dallia pectoralis T. H. Bean, 1880 [2] | |
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| Range of Dallia pectoralis | |
The Alaska blackfish (Dallia pectoralis) is a species of freshwater fish in the esocid family (Esocidae) of order Esociformes. It inhabits Arctic regions of Alaska as well as Siberia and the Bering Sea islands.
Alaska blackfish are small, with an average length of 108 mm (4.3 in), but have been known to reach 330 mm (13 in). [3]
They have an easily distinguishable morphology (a branch of biology dealing with the study of the form and structure of organisms and their specific structural features), with relatively large, posterior dorsal fin and anal fins, large, lobed pectoral fins located just posterior to the operculum, a diphycercal caudal fin, and small, pointy pelvic fins. [4]
The head is broad and flat, with the trunk being long and slender. The color is dark green to brown on the dorsal side, pale below, with light-colored blotches appearing laterally. [4]
Males can be distinguished from females by the presence of a reddish fringe along the dorsal, caudal, and anal fins; also, the tips of the ventral fins extend beyond the anal fin in males, whereas in females they do not. [4] [3]
The Alaska blackfish is famous for its ability to breathe atmospheric oxygen through a modified esophagus. [5] Specifically, the esophagus of a blackfish can be subdivided into a non-respiratory and a respiratory section. The respiratory section can be identified by its extensive mucosal folding and vascularization, as well as widespread capillaries throughout the epithelium. [5] This respiratory structure implies selection pressures for the development of a purely respiratory organ and a purely hydrostatic organ. [5] Another factor is the retention of the hydrostatic swim bladder, which seems unnecessary unless it is important in maintaining neutral buoyancy in the cold winter months under ice cover. [5]
Alaska blackfish can be found in the Bering Sea islands, Siberia, and Alaska. [3] In Alaska, they inhabit the Colville Delta south to the central Alaska Peninsula near Chignik as well as the upstream Yukon-Tanana drainage to near Fairbanks. [3]
Blackfish are found in highly vegetated swamps and ponds, occasionally residing in rivers and densely-vegetated lakes, where in summer, water is frequently stagnant. [4] [5] Spawning migrations are limited to inshore and upstream movements in the spring, and reverse migrations to deeper water in the fall. [3]
In the winter-time, blackfish tend to reside in the benthic regions of lakes, although when oxygen availability reaches a certain minimum, blackfish move to the surface, grouping around breathing holes. [6] These breathing areas can be preexisting holes, such as those created by muskrats, beavers, and fishers, or simply thin layers of ice. Blackfish have been observed schooling below the ice, and when swimming upwards to breathe, eat away at the ice and creating an audible snapping or sucking sound. [6] The Alaska blackfish is known for its tolerance of cold water, and has been reported to survive exposure to −20 °C (−4 °F) for 40 minutes. [3] Despite its hardiness, Alaska blackfish have been observed to suffer edema and mass mortality events during the winter. [7]
The principal source of food for blackfish is aquatic insects and invertebrates, although in Bristol Bay, larger blackfish have been observed to be cannibalistic, as well as predators of young pike. [4] Blackfish are generalist feeders, and have been analyzed to have contained algae, snails, dipteran larvae, ostracods, copepods, and caddisfly larvae in their stomachs. [8]
Spawning occurs from May to August, with fish having the ability to spawn several times; thus, females do not usually expel their entire egg contents in a single event. [4]
A female, depending on her size, can release a total of 40-300 eggs at intervals during the spawning period, with the eggs then attaching to vegetation and hatching in a short period of time (nine days at 12 °C (54 °F)). [4] When the young hatch, they are approximately 6 mm in length, and survive off the yolk sac for an average period of 10 days. [4]
Rate of growth varies throughout Alaska, with blackfish from Interior Alaska and the Anchorage area being about 108 mm (4.3 in) at age 2, 138 mm (5.4 in) at age 3, and 178 mm (7.0 in) at age 4. On the other hand, Bristol Bay blackfish are much slower growing and longer lived. Four-year-old fish are approximately 64 mm (2.5 in) in length, but can live up to 8 years. [4] Female blackfish have been shown to reach sexual maturity at 80 mm (3.1 in). [4]
The Alaska blackfish is an important subsistence fish for Native communities residing in the Interior and Western Alaska, specifically those residing in Interior Alaska. [6] Although generally small (average size is 108 mm (4.3 in)), [3] their significance comes in their high nutritional value and large abundance in the winter, a generally lean time of year. [6]
When oxygen levels in the benthic regions of lakes becomes low, blackfish move to the surface to obtain atmospheric oxygen, thus making ice fishing an easy method of capture; blackfish are commonly stored, frozen, and then fed to dogs, with certain Alaskan stories recollecting moments when blackfish would seemingly revive themselves upon thawing. [6] Metabolic and survival studies have been conducted without successful replication of this observation.
The Alaska blackfish is not International Union for Conservation of Nature-listed as an endangered or threatened species. [3] While blackfish are native to Western Alaska as well as the Interior, they were introduced to the Cook Inlet Basin of Alaska in the 1950s, and have since become widespread. [9] A study performed by Eidam et.al. (2016) in three study sites in the Cook Inlet Basin concluded that an insignificant portion of their diet was fish, meaning blackfish are unlikely to impact native and stocked fish in those populations. While that information is helpful for determining whether blackfish are truly invasive, it is not all-encompassing for other blackfish populations in the area. Further studies are warranted that estimate the abundance of introduced blackfish in lakes and streams in the Cook Inlet Basin, as well as investigate potential dietary overlap with other fish.
Molecular study of Alaska blackfish across its range has identified several geographic areas where Alaska blackfish persisted during glacial episodes. [10] [11] Genetic structuring within the species is relatively high for a fish species from northern latitudes, most likely reflecting biological characteristics such as poor dispersal ability and winter survival. [10] [11] [12]
Esocidae is a family of fish in the order Esociformes, which contains pike, pickerel, and mudminnows. While the family traditionally only contained the genus Esox, recent genetic and paleontological research have recovered Novumbra and Dallia as members of the family Esocidae, being closer related to Esox than Umbra. Fossil specimens from the Mesozoic in North America have been assigned as two additional genera in this family.
The Esociformes is a small order of freshwater ray-finned fish, with two families, Umbridae and Esocidae. The pikes of genus Esox give the order its name.
The northern pike is a species of carnivorous fish of the genus Esox (pikes). They are commonly found in moderately salty and fresh waters of the Northern Hemisphere. They are known simply as a pike in Great Britain, Ireland, most of Eastern Europe, Canada and the U.S.
The ide, or orfe, is a freshwater fish of the family Cyprinidae found in larger rivers, ponds, and lakes across Northern Europe and Asia. It has been introduced outside its native range into Europe, North America, and New Zealand. It is a popular ornamental fish, usually kept in outdoor ponds in temperate regions from which it often escapes.
The bowfin is a bony fish, native to North America. Common names include mudfish, mud pike, dogfish, grindle, grinnel, swamp trout, and choupique. It is regarded as a relict, being one of only two surviving species of the Halecomorphi, a group of fish that first appeared during the Early Triassic, around 250 million years ago. The bowfin is often considered a "primitive fish" because they have retained some morphological characteristics of their early ancestors. It is one of two species in the genus Amia, along with Amia ocellicauda, the eyespot bowfin. The closest living relatives of bowfins are gars, with the two groups being united in the clade Holostei.
The mummichog is a small killifish found along the Atlantic coast of the United States and Canada. Also known as Atlantic killifish, mummies, gudgeons, and mud minnows, these fish inhabit brackish and coastal waters including estuaries and salt marshes. The species is noted for its hardiness and ability to tolerate highly variable salinity, temperature fluctuations from 6 to 35 °C, very low oxygen levels, and heavily polluted ecosystems. As a result, the mummichog is a popular research subject in embryological, physiological, and toxicological studies. It is also the first fish ever sent to space, aboard Skylab in 1973.
The chum salmon, also known as dog salmon or keta salmon, is a species of anadromous salmonid fish from the genus Oncorhynchus native to the coastal rivers of the North Pacific and the Beringian Arctic, and is often marketed under the trade name silverbrite salmon in North America. The English name "chum salmon" comes from the Chinook Jargon term tzum, meaning "spotted" or "marked"; while keta in the scientific name comes from Russian, which in turn comes from the Evenki language of Eastern Siberia. The term 'Dog Salmon' is most commonly used in Alaska and refers to the Salmon whose flesh Alaskans use to feed their dogs.
The Arctic grayling is a species of freshwater fish in the salmon family Salmonidae. T. arcticus is widespread throughout the Arctic and Pacific drainages in Canada, Alaska, and Siberia, as well as the upper Missouri River drainage in Montana. In the U.S. state of Arizona, an introduced population is found in the Lee Valley and other lakes in the White Mountains. They were also stocked at Toppings Lake by the Teton Range and in lakes in the high Uinta Mountains in Utah, as well as alpine lakes of the Boulder Mountains (Idaho) in central Idaho.
Pink salmon or humpback salmon is a species of euryhaline ray-finned fish in the family Salmonidae. It is the type species of the genus Onchorhynchus, and is the smallest and most abundant of the seven officially recognized species of salmon. The species' scientific name is based on the Russian common name for this species gorbúša (горбуша), which literally means humpie.
The Sacramento blackfish is a species of freshwater fish in central California. A cyprinid, the blackfish is the sole member of its genus.
The round whitefish is a freshwater species of fish that is found in lakes from Alaska to New England, including the Great Lakes. 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 emerald shiner is one of hundreds of small, silvery, slender fish species known as shiners. The identifying characteristic of the emerald shiner is the silvery emerald color on its sides. It can grow to 3.5 inches in length and is found across North America from Canada to the Gulf of Mexico, commonly in large, deep lakes and rivers, though sometimes in smaller bodies of water as well. It feeds on small organisms such as zooplankton and insects, congregating in large groups near the surface of the water. It is a quite common fish and is often used as a bait fish.
The coastal cutthroat trout, also known as the sea-run cutthroat trout, blue-back trout or harvest trout, is one of the several subspecies of cutthroat trout found in Western North America. The coastal cutthroat trout occurs in four distinct forms. A semi-anadromous or sea-run form is the most well known. Freshwater forms occur in both large and small rivers and streams and lake environments. The native range of the coastal cutthroat trout extends south from the southern coastline of the Kenai Peninsula in Alaska to the Eel River in Northern California. Coastal cutthroat trout are resident in tributary streams and rivers of the Pacific basin and are rarely found more than 100 miles (160 km) from the ocean.
The snakeskin gourami is a species of gourami native to Southeast Asia. Prior to the merging of Belontidae to the family Osphronemidae, the snakeskin gourami was regarded as the largest member of its family. It is still the largest species in its genus and subfamily.
The shortspine thornyhead, also known as the channel rockcod, shortspine channel rockfish or spinycheek rockfish, is a species of marine ray-finned fish belonging to the subfamily Sebastinae, the rockfishes, part of the family Scorpaenidae. It is sometimes referred to as the "idiot fish" or "idiot cod" due to its large oversized head and eyes. It is found in the northern and northeastern Pacific Ocean.
The central mudminnow is a small fish in the family Umbridae of the order Esociformes. It is found in central and eastern North America in productive waters. It is fairly tolerant of low oxygen concentrations and, as a result, it is sometimes the only, or one of a very few, fish species present in waters susceptible to winter or summer kill.
Umbridae is a family of fish in the order Esociformes, which contains pike, pickerel, and mudminnows. The single living genus, Umbra, occupies weed-choked freshwater habitats in eastern North America and eastern Europe. While the family traditionally contained the genera Umbra, Novumbra, and Dallia, recent genetic and paleontological research have recovered this grouping as paraphyletic, with Novumbra and Dallia being moved to the family Esocidae.
Dallia is a genus of mudminnows native to Russia and Alaska. Molecular data indicates the genus is more closely related to Esox and Novumbra than Umbra.Dallia diverged from Novumbra + Esox approximately 66 million years ago.
The redfin pickerel is a subspecies of freshwater fish belonging to the pike family (Esocidae) of the order Esociformes. Not to be confused with its close relatives, the grass pickerel and the chain pickerel, this fish is unique in the fact that it has brightly colored red fins. Like all pikes, the redfin pickerel is an ambush predator, lying amongst thick vegetation in wait for smaller, more agile prey to enter within its range of attack.
Yup'ik cuisine refers to the Eskimo style traditional subsistence food and cuisine of the Yup'ik people from the western and southwestern Alaska. Also known as Cup'ik cuisine for the Chevak Cup'ik dialect speaking Eskimos of Chevak and Cup'ig cuisine for the Nunivak Cup'ig dialect speaking Eskimos of Nunivak Island. This cuisine is traditionally based on meat from fish, birds, sea and land mammals, and normally contains high levels of protein. Subsistence foods are generally considered by many to be nutritionally superior superfoods. Yup’ik diet is different from Alaskan Inupiat, Canadian Inuit, and Greenlandic diets. Fish as food are primary food for Yup'ik Eskimos. Both food and fish called neqa in Yup'ik. Food preparation techniques are fermentation and cooking, also uncooked raw. Cooking methods are baking, roasting, barbecuing, frying, smoking, boiling, and steaming. Food preservation methods are mostly drying and less often frozen. Dried fish is usually eaten with seal oil. The ulu or fan-shaped knife used for cutting up fish, meat, food, and such.
