Mottled sculpin eat mainly aquatic insect larvae, such as mayfly nymphs, caddisfly larvae, stonefly larvae and midges, but also eat small crustaceans, such as amphipods, copepods, and ostracods, they also eat leeches, smaller fish, fish eggs, and some aquatic plant material and algae.
Animal Foods: fish; eggs; insects; terrestrial worms; aquatic crustaceans
Plant Foods: leaves; algae
Primary Diet: carnivore (Insectivore )
Mottled sculpin have been reported as prey by brook trout, brown trout, northern pike, common mergansers, and water snakes. They are also likely prey of wading birds, such as herons.
Known Predators:
Anti-predator Adaptations: cryptic
Mottled sculpin are small, stout fish with relatively flattened bodies. They have round snouts and are cryptically colored, with brown to black mottling on their backs, sides, and fins and whitish bellies. They have 2 dorsal fins, the first with 6 to 9 soft spines and the second with 17 to 19 rays. There is a small black spot on the first part of the first dorsal fin, which helps to distinguish them from round gobies, and a larger spot on the back of the first dorsal fin. They do not have obvious scales, although they have a line of small prickle-like scales below their lateral line, which is incomplete and ends just under the second dorsal fin. Males are slightly larger than females and during the breeding season males have a dark band on the first dorsal fin and a broad, orange band on the edge of the fin.
Range length: 76 to 102 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: male larger; male more colorful
Average recorded lifespan in mottled sculpin is 2 years.
Average lifespan
Status: wild: 2 years.
Mottled sculpin are found in gravel bottoms and sandy riffles of small headwaters, streams, and small rivers or in rocky shoreline areas of lakes, including the Great Lakes. The type of bottom may be less important than the presence of cover, which can be gravel, stones, or submerged vegetation. They can be found at up to 16 meters depth. Mottled sculpin seem to prefer depths of 0.1 to 0.5 meters and cold, clear water.
Range depth: 16 (high) m.
Average depth: 0.1 to 0.5 m.
Habitat Regions: temperate ; freshwater
Aquatic Biomes: lakes and ponds; rivers and streams
Mottled sculpin are widespread in North America, with a broadly disjunct range. Eastern populations occur throughout the Great Lakes region, north to Hudson Bay and throughout much of eastern Canada and south to northern Alabama and Mississippi. There is a disjunct population in Missouri and a large western population in the northern Rocky Mountain states, from British Columbia and Alberta south to southern Nevada and northern New Mexico.
Biogeographic Regions: nearctic (Native )
Mottled sculpin are very important intermediate predators in native aquatic ecosystems. They prey on small aquatic animals, mostly invertebrates, and form an important prey base for larger fish, such as brook trout and northern pike. They may also help trout populations through their predation on stoneflies, which each trout eggs and young. Mottled sculpin are hosts for the glochidia of several native clam species, including cylindrical papershells and slippershell mussels. Mottled sculpin may compete directly with round gobies, an invasive species in the Great Lakes.
Mottled sculpin are very important intermediate predators in native aquatic ecosystems. They prey on small aquatic animals, mostly invertebrates, and form an important prey base for larger fish, such as brook trout and northern pike. They may also help trout populations through their predation on stoneflies, which each trout eggs and young. Mottled sculpin are hosts for the larvae of some native clam species, including cylindrical papershells and slippershell mussels. Mottled sculpin may compete directly with round gobies, an invasive species in the Great Lakes.
Commensal/Parasitic Species:
Healthy populations of mottled sculpin are used as an indicator of healthy trout populations, which are very important gamefish. Mottled sculpin have been demonstrated to have a positive effect on trout populations through preying on stoneflies, which prey on trout young and eggs, and because they are important prey for large trout.
There are no negative effects of mottled sculpin on humans. Some have regarded them as serious predators of trout eggs, but research suggests that their predation on trout eggs is usually on drifting eggs that won't develop anyway. Healthy mottled sculpin populations are used as an indicator of healthy trout populations because they are important prey of trout.
Mottled sculpin egg development depends on water temperature, at temperatures of 11 to 13 degrees Celsius eggs hatched in 17 days. Mottled sculpin larvae are about 5.9 mm in length when they hatch and leave the nest when they reach about 6.7 mm long and have used up their yolk sac, at about 14 days after hatching.
Based on courtship behaviors, visual and tactile cues are likely to be used by mottled sculpin in communication. They may also have good chemoreception, as in most fish. Mottled sculpin have a lateral line system that helps them to perceive water movements and pressure changes.
Communication Channels: visual ; tactile
Perception Channels: visual ; tactile ; vibrations ; chemical
Mottled sculpin are also known as common sculpin, northern muddler, muddler, blobs, gudgeons, muffle-jaws, bullheads, springfish, lake sculpin, spoonheads, and miller's thumbs. Their generic name, Cottus, is from an old European name for sculpin.
Mottled sculpin populations are not considered threatened currently. This is a widespread species with large populations. However, introduced round gobies may dramatically effect mottled sculpin populations through predation and competition.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Male mottled sculpin use courtship movements to attract females to their nest cavities. They shake their heads, raise their gills, and undulate their bodies to get the attention of females. The color and band on their dorsal fin is probably also involved in courtship, as it only appears during the breeding season. When a female approaches, the male will bite her cheek, side, fins, or tail or else grab her by the head and pull her into the nest cavity. Once inside the nest cavity, the female turns upside down so that she can release her eggs onto the cavity ceiling. The male accompanies the female into the cavity and arranges himself next to her. The male's head and fins then become jet black and his body becomes pale. The male blocks the nest cavity entrance for several days so that the female remains inside. Males eventually attract several (average 3.3) females into their nests to mate.
Mating System: polygynous
Male mottled sculpin begin to defend nest cavities in the spring. Nest cavities are areas beneath rocks or other debris at depths of about 22 cm and in areas with enough water flow to prevent silt build up. Nest entrances usually face upstream. Males attract females to their nests, where the females remain for a few days and lay their eggs. Males then remain in the nest cavities until the eggs hatch and the young fish leave the nest a few weeks after hatching. In Wisconsin, males are in nests from April to the end of May. Females are recorded to have from 111 to 635 (average 328) eggs at a time. Eggs hatch in about 17 days and young depart from the nest about 14 days after that. Sexual maturity is reached at adult sizes of 59.2 mm in males and 53.1 mm in females, sizes that can be reached within a year of hatching.
Breeding interval: Mottled sculpin breed once yearly.
Breeding season: Mottled sculpin breed in the spring. In Wisconsin breeding occurs from early April through May.
Range number of offspring: 111 to 635.
Average number of offspring: 328.
Average gestation period: 17 days.
Average time to independence: 14 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); oviparous
Male mottled sculpins guard clusters of eggs that have been laid by different females. They protect the eggs from predators until they hatch.
Parental Investment: pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Protecting: Male)
Cottus bairdii és una espècie de peix pertanyent a la família dels còtids.
Fa la posta a la primavera i el mascle s'encarrega de protegir els ous dipositats per diferents femelles.[8][9]
Menja larves d'insectes aquàtics, crustacis, anèl·lids, peixos, ous de peixos i matèria vegetal.[10]
És un peix d'aigua dolça, demersal i de clima temperat (59°N-34°N).[5][11]
Es troba a Nord-amèrica: el Canadà i els Estats Units.[5][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]
És inofensiu per als humans.[5]
The mottled sculpin (Cottus bairdii) is a species of freshawater 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 mottled sculpin (Cottus bairdii) is a species of freshawater 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.
Le Chabot tacheté (Cottus bairdii) est une espèce de poissons de la famille des Cottidae présent en Amérique du Nord.
Ce poisson est présent au Canada et aux États-Unis.On le trouve par exemple dans le bassin du fleuve Columbia et dans la rivière Missouri.
Sa première nageoire dorsale est garnie d'épines et quasiment reliée à la seconde. La taille maximum de ce chabot est d'environ 15 centimètres. Comme son nom vernaculaire l'indique, le chabot est recouvert de taches sur tout son corps.
Il se nourrit principalement de larves d'insectes mais aussi de crustacés, d'œufs de poissons ou même de petits poissons. Son régime alimentaire est également constitué de quelques végétaux. Les plus gros poissons comme la truite sont ses prédateurs. Il apprécie les eaux claires et bien oxygénées que ce soit dans des rivières de montagne ou dans des lacs dont les berges sont rocailleuses.
La fraie a lieu du début de l'hiver à la fin du printemps. La tête du mâle devient plus noire et il choisit un lieu protégé pour son nid, par exemple sous un rocher. Une ou plusieurs femelles le rejoignent dans ce lieu pour y déposer leurs œufs. Le mâle fertilise ensuite les œufs et protège l'endroit.
Le Chabot tacheté (Cottus bairdii) est une espèce de poissons de la famille des Cottidae présent en Amérique du Nord.
Cottus bairdii Girard, 1850, è una specie di pesce osseo facente parte della famiglia Cottidae e originaria del Nord America.
È presente in Canada come specie nativa e negli Stati Uniti sia come specie nativa che introdotta.
A questa specie fanno capo alcune sottospecie:
Cottus bairdii Girard, 1850, è una specie di pesce osseo facente parte della famiglia Cottidae e originaria del Nord America.
Cottus bairdii is een straalvinnige vissensoort uit de familie van donderpadden (Cottidae).[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1850 door Girard. De naam werd gegeven als eerbetoon aan de Amerikaanse bioloog Spencer Fullerton Baird.
Bronnen, noten en/of referenties
本魚成魚棲息在碎石激流，較不常見於沙石底質的河川源頭，另也發現於泉水與湖溢流與岩岸。為底棲性魚類，雜食性，主要捕食水生昆蟲維生，也捕食甲殼動物、環節動物、小魚、魚卵與植物。行一夫多妻制，繁殖期在春天，雄魚負責保衛魚卵。體長可達15公分。
