Mottled sculpin | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Scorpaeniformes |
Family: | Cottidae |
Genus: | Cottus |
Species: | C. bairdii |
Binomial name | |
Cottus bairdii Girard, 1850 | |
Synonyms [2] | |
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The mottled sculpin (Cottus bairdii) is a species of freshwater ray-finned fish belonging to the family Cottidae, the typical sculpins. This species has a wide but scattered North American distribution.
As the name suggests, its coloration is a combination of bars, spots, and speckles randomly distributed. The large pectoral fins are banded. The first dorsal fin is made of slender and somewhat soft spines, and just barely joins with the second dorsal. Maximum length is 15 cm.
It feeds primarily on aquatic insect larvae, but will also eat crustaceans, small fish, fish eggs, and some plant material. In turn, the sculpin is preyed upon by other fish, notably trout. Favored habitat is well-oxygenated and clear water, such as over gravel riffles in mountain streams, springs, and along rocky lake shores.
Spawning takes place during early winter and late spring. The male's head becomes darker, and he selects a protected nest site, such as under a rock or ledge. After courtship, the female enters the nest, turns upside down, and deposits her eggs on the ceiling, where they adhere. Typically several females will deposit eggs in a nest, then the male fertilizes and guards them, fanning the eggs with his pectoral fins.
Mottled sculpin occurrence is discontinuous in its range. It is widespread from the Tennessee River north to Labrador, while separate populations are found in the Missouri River, the Columbia River system in southern Canada, and the Bonneville system of the Great Basin.
Mottled sculpins, Cottus bairdi, are a common fish throughout most of North America. The only area that mottled sculpin are provided limited protection is in New Mexico. [3] Mottled sculpins feed on a wide variety of organisms, including mollusks, snails, other mottled sculpins, and trout. Their diets are mainly made up of bottom-dwelling benthic insects. [4] The favored habitat of a mottled sculpin is one rich in macroinvertebrate prey, which usually occurs in fast riffle areas [5] with clear substrates and moderate velocities between 0.20 m/s to 0.38 m/s. [6] Spawning season for the mottled sculpin starts in April or May [7] with the males taking up residency in benthic rocks. Breeding season lasts for two to three months. [8] Clutch size can vary anywhere from 8 eggs to 148 eggs for females. Males can have up to 1587 eggs in their nest. Sexual maturity is thought to be reached at two years of age. Climate change does not seem to be a threat to this species since they inhabit a wide range of temperature gradient throughout the United States. However, one human activity that affects them is runoff from mining, which particularly is harmful to the newly hatched larvae and developing eggs. [9] Nothing is being done for current management for the mottled sculpin because it is a very abundant fish where it occurs. Future management could focus on the different metals that leak into the water from mining. The absence of the mottled sculpin from an area could tell us that the area has high levels of zinc, cadmium, or copper. [9]
The mottled sculpin, Cottus bairdii, is known to inhabit a large geographical range in North America. Their natural habitat range is from Northern Canada down to the Mobile and Tennessee River drainage systems. They are also commonly found in streams in the Rocky Mountains along with many streams found throughout the Midwest United States. The mottled sculpin has historically been found throughout all the environments listed above. For the most part, the geographical range of the mottled sculpin has not changed throughout the years due to it is being a resilient fish and because it has a large temperature gradient in which it can reside. However, in a study by Besser and others in 2007, mottled sculpins have been absent in streams thought to be populated by them in the past due to the species being more sensitive to toxic levels of cadmium, copper, and zinc than species of salmonids. [9] Of these three metals zinc seems to be the most threatening to the mottled sculpin. One study found mottled sculpins to be the third most sensitive aquatic species to zinc. [10] Therefore, the biggest threat to the species would be high mining areas or areas where coal is burned frequently.
Mottled sculpins are known for living in fast moving current areas where they feed primarily on bottom dwelling aquatic insects. One study found that bottom dwelling aquatic insects make up 99.7% of the mottled sculpin's diet, with dipterous larvae and pupae being the most common type found. [4] The remaining 0.3% was made up of snails, fingernail clams, water mites, sculpin eggs and fish. [4] Thus the mottled sculpin is not a major threat to game fish though it has been found to eat trout eggs. [4] [11] Sculpin are cannibalistic. Males are known to eat their young if one contracts some kind of virus or fungus. The males also eat small females. Therefore, older females are usually chosen for mates over younger females. [4] [7]
The main predators of the sculpin are different species of game fish, such as brook trout, brown trout, northern pike, and smallmouth bass. All sculpin species are expected to coexist with species from the family Salmonidae. [11] Its main competitors are other small bottom dwelling fish, especially other sculpin species. [6] Female and immature mottled sculpins are commonly found in clean water rock substrates. On the other hand, males are commonly found in algae beds. The mean current velocity in which the fish is found is 0.28 m/s. They prefer to inhabit cool clear streams. They will tolerate warmer streams but do not prefer them like Cottus girardi. [6]
Mottled sculpin reach sexual maturity at the age of two. [12] The breeding season for mottled sculpin is during April and May. [7] At the beginning of the season the males will take refuge under flat-bottomed rocks, waterlogged wood or other rubble found in stream beds. In order to mate the female will come up to the males nest and lay her eggs there. The female chooses her mate on physical attributes. Since larger males pick out nesting sites with better resources qualities, the female's choice of the largest male indicates she is picking good genes in a mate and also a good environment for her young to grow up [13] After mating she either leaves or is chased away by the male. The males do this because females will eat the eggs right after spawning if the male does not run her off. [14] The males continue to protect the eggs until they have absorbed their yolk sac and are ready to distribute themselves. [15]
Mottled sculpins only mate once a year. The clutch size can vary anywhere from 8 eggs to 148 eggs for females. However within that year one male could mate with ten or more females [13] This leads to very large nest sizes. One study looked at twelve different nesting sites within a year and found that one nest can have anywhere from 54 to 1587 eggs with an average of 744 eggs per nest. [4] Mottled sculpins' average life span is six years.
The mottled sculpin is currently not federal or state listed for being threatened or endangered. In New Mexico the species is given limited protection. The reason for the species receiving no current management plan is due to its high abundance all over North America. Its high prevalence is due to the species tolerance' for all types of environment.
Although the species is not threatened anywhere in North America, it has received attention in recent areas in the Western United States due to its absence in some streams that are highly populated with trout species but not sculpins. This was odd since the two species usually coexist in similar habitats. The problem was that the streams absent of sculpin had high concentrations of zinc. [10] One study showed that mottled sculpin are the third most sensitive species to high levels of zinc. [10] The reason this occurring is because the U.S. Environmental Protection Agency (EPA) uses trout species to determine the water quality criteria (WQC) for zinc. [16] Therefore, the WQC standards are not good enough to protect all species of fish. In southeast Minnesota there are plans to rebuild the sculpin population in streams where the water quality was once unfavorable for the species but has since been improved. The next step is to introduce 200 mottled sculpin a year until the population is showing signs of a comeback in the local streams.
However zinc is not the only metal threatening mottled sculpin populations. One study found mottled sculpins were also more sensitive to levels of copper and cadmium than other species of fish. [9] The leading causes of increase of these three metals into aquatic environments are from mining, the burning of coal, steel production, and smelting metals.
The spoonhead sculpin is a species of freshwater ray-finned fish belonging to the family Cottidae, the typical sculpins. This species is widespread in northeastern North America.
The slimy sculpin is a freshwater species of fish belonging to the family Cottidae, which is the largest sculpin family. They usually inhabit cold rocky streams or lakes across North America, ranging from the Great Lakes, southeast Minnesota, northeast Iowa, southwest Wisconsin and northeast Canada. Slimy sculpins have also been found roaming the cold streams of eastern Siberia. They are commonly confused with their closely related relatives, Mottled sculpin, and with tubenose gobies who are both freshwater fishes as well. The slimy sculpin is a nocturnal fish that usually spends most of its time on the stream bottom and seeks shelter under rocks and logs, especially during spawning season. When it swims, it sometimes appears to be "hopping" along the bottom because of its inefficient ability to swim. This is partly due to the absence of a swim bladder, which normally gives buoyancy to a fish.
The European bullhead is a freshwater fish that is widely distributed in Europe, mainly in rivers. It is a member of the family Cottidae, a type of sculpin. It is also known as the miller's thumb, freshwater sculpin, common bullhead, and cob.
The common river galaxias or Canterbury galaxias is a galaxiid fish of the genus Galaxias, found only in Canterbury, New Zealand.
The redfin bully is a species of freshwater fish in the family Eleotridae endemic to New Zealand. Being amphidromous, it spends part of its life cycle at sea. Males have distinctive bright red patterns and stripes on their fins. Adults grow to an average of 80–100 mm (3.1–3.9 in) total length, with a maximum of 120 mm (4.7 in).
The brook stickleback is a small freshwater fish that is distributed across the US and Canada. It grows to a length of about 2 inches. It occupies the northern part of the eastern United States, as well as the southern half of Canada. Small populations are scattered throughout the Mississippi-Great Lakes basin extending to Colorado, New Mexico, Kentucky, Tennessee, etc., though some of these areas are not native to the species. This small fish inhabits clear, cool streams and lakes. They eat small invertebrates, algae, insect larvae, and occasionally their own eggs. They are also preyed upon by smallmouth bass and northern pike. Feedin time is usually dawn and sunset. The brook stickleback does have active competition mostly from minnows, but feeding times are different, along with diet. Spawning occurs in midsummer. Males secure a territory, build a nest, and mate with females. Males provide protection for the eggs, ward off predators, and usually die later in the season. This is considered an annual species. The nests are built out of aquatic grasses. Though the brook stickleback is not considered a threatened species, deforesting and changing waters are altering ecosystems of the species. Harvesting of trees around riparian environments is having a large effect of the stream ecosystem where the brook stickleback resides.
The alpine bullhead or Siberian bullhead is a species of freshwater fish in the family Cottidae of sculpins. It is found in China, the Czech Republic, Denmark, Finland, Germany, North Korea, Moldova, Norway, Poland, Romania, Russia, Slovakia, Sweden, and Ukraine. This fish is listed as being of "Least Concern" by the IUCN.
The oyster mussel is a rare species of freshwater mussel in the family Unionidae. This aquatic bivalve mollusk is native to the Cumberland and Tennessee River systems of Kentucky, Tennessee, Alabama, and Virginia in the United States. It has been extirpated from the states of Georgia and North Carolina. It is a federally listed endangered species of the United States.
Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, to spawn refers to the process of freely releasing eggs and sperm into a body of water ; the physical act is known as spawning. The vast majority of non-mammalian, non-avian and non-reptilian aquatic and/or amphibious lifeforms reproduce through this process, including the:
The banded sculpin is a freshwater fish dwelling mostly in small to moderate sized streams in areas of swift current. Young and juvenile C. carolinae can mainly be found in pools, riffles, and other shallow habitats while adults tend to prefer deeper waters. C. carolinae primarily eats insects and insect larvae, but their large mouths enable them to eat prey nearly as large as themselves, including other sculpin. To prevent predation, including by other fish, the color and pattern of the sculpin tends to match its environment. Most Cottus carolinae are mottled brown with dark vertical banding and usually reach about three inches in length. They have a broad head which rather quickly narrows into a slim body, giving them the appearance of a tadpole reaching adulthood.
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The Coastrange sculpin is a freshwater sculpin of the genus Cottus. They are commonly found near the ocean in western North America, namely Canada and the United States. It is also known as the Aleutian sculpin.
The prickly sculpin is a species of ray-finned fish belonging to the family Cottidae, the typical sculpins. It is native to the river drainages of the Pacific Slope of North America from Seward, Alaska south to the Ventura River of Southern California. It extends east of the Continental Divide in the Peace River of British Columbia. It has also been introduced to several reservoirs in Southern California.
Acanthocephalus dirus is a species of parasitic worm in the Echinorhynchidae family. Instead of having its eggs expelled from the host in feces, the gravid female detaches itself from the host's digestive tract and sinks to the bottom, where her body is consumed by the species' intermediate host, Caecidotea intermedius, a species of isopod. Upon hatching, the larvae begin to alter their host's behavior. This will manifest in lighter pigmentation and an increased attraction to predators, such as A. dirus' primary hosts.
The shorthead sculpin is a species of fish in the family Cottidae. Shorthead Sculpins are bottom-dwelling small fish, typically sizing around 13 to 15 cm long. They have large heads and fanlike pectoral fins. They have 7-9 dorsal spines, 15-19 dorsal soft rays, and 10-14 anal soft rays. Narrow caudal peduncle. Palatine teeth and coloration being dark brown and yellow.
The inland riffle sculpin is a species of fish in the family Cottidae. It is found in the United States, inhabiting the lower Columbia River drainage in Washington, to Morro Bay in California. It is also found in the Puget Sound drainage in Washington. It reaches a maximum length of 11.0 cm. It prefers rocky riffles of headwaters and creeks.