The hardhead catfish ( Ariopsis felis ) is a species of sea catfish from the northwest Atlantic and Gulf of Mexico, and is similar to the catfish gafftopsail ( Bagre marinus ). It is one of four species in the genus Ariopsis. The common name, the hardhead catfish, comes from the presence of a hard bone plate that extends backward toward the dorsal fin of the line between the eyes of the catfish. It is a sea catfish whose length reaches up to 28Ã, (70Ã, cm) and weighs 12 lb (5.5 kg). The average weight is less than 1 pound (450 g), but they generally reach up to 3 pounds (1.4 kg). They are often a dirty gray color at the top, with white bottom.
Video Hardhead catfish
Habit, distribution, and characteristics
The Catfish Hardhead is found mostly in the waters near the coast of the West Atlantic Ocean, around the southeastern coast of the United States, around the Florida Keys and the Gulf Coast of Mexico. Catfish Hardhead is also found in the brackish estuary and river estuaries where the bottom is sandy or muddy, but only occasionally into the fresh water. It tends to move from shallower to deeper waters in winter. This species is generally abundant in its range.
Hardhead catfish has four spines beneath the chin, with two more in the corner of the mouth. This thorn helps catfish find crabs, fish and shrimp in the muddy bay where they live. The dorsal and pectoral fins are each supported by a slimy, sharp spine. The back spine is usually erect when the fish is attracted and the tennis shoes or even the leather-soled shoes offer little protection. Gafftopsail catfish looks similar to a hardhead catfish, but its backbone has distinctive fleshy extensions (like the front of the front and rear vessels).
Maps Hardhead catfish
Feeding Behavior
Ariopsis felis consume a variety of foods. Catfish Hardhead is an opportunistic consumer who uses mud and sand as a hunting ground. They are also mostly secondary consumers, mainly consume detritus, meio, and macrobenthic fauna and fish. Their diet consists mainly of algae, seagrass, cnidaria, sea cucumbers, gastropods, polychaetes, shrimp, and crabs. They can sometimes become tertiary consumers. Their diet depends on their size and location. Younger hardhead catfish tend to eat small crustaceans, such as amphipods, shrimp, blue crabs, mollusks, and annelids. Teenagers who are still under the protection of the male mouthmoder will feed especially on the planktonic crustaceans close to the mother's mouth. Adults mainly consume larger fish.
Locomotion
Significant evidence suggests a correlation between patterns of fish activity and seasonal changes. Under controlled conditions of photoperiod, temperature, and water quality, hardhead catfish displays non-random oscillations in the orientation of the angle of locomotive activity. There seems to be an annual, bimodal cycle for the three variables mentioned above. This cycle corresponds to the migration of seasonal hardhead dolphins offshore. Photoperioda seems to be an exogenous cue that triggers cyclic changes in behavior. The presence of this seasonal behavior suggests that there may be circadian neural mechanisms in hardhead catfish.
Communications
Chemistry
Studies show that hardhead catfish respond to chemicals released by injured individuals with increased activity, which describes communication among catfish. Their activity level is highest after the onset of chemical stimulus. In the study, they also responded to chemical cues from the wounded sailfin mole, but this response was weaker than the response of their own species. After examining the hardhead catfish epidermis, it turns out that the cells of an alarm substance are similar to the freshwater catfish. Prior to this research, this chemical response was only seen in freshwater ostariophysans. The Catfish Hardhead is the first marine ostariophysans to cause this kind of alarm reaction.
Echolocation
In addition, hardhead catfish is the first indicator that steichthyes may be able to use hearing directions to detect obstacles. Through observation, the researchers noted that low-frequency sound emissions are associated with detection and avoidance from near by obstacles. Individuals in the group that produce barriers are avoided by sound, while silent individuals often crash into obstacles. Many fish have been associated with sound production for alarms, territory, and courtship purposes, but the environmental probing sound seems to only be seen in hardhead catfish. So far, there is no evidence for far-field echolocation, as seen in bats or toothed whales. The signal parameters have low frequency and amplitude, so it is not possible to remote field echoes will be useful. If there is an ecolocation, it is likely only useful in the field near by catfish.
Sound production
There is some evidence that sound production in hardhead catfish is mechanically and contextually differentiated. Mechanically, sound can be produced in different ways. There is a thin bone by the swim bladder that can be vibrated by a special sonic muscle. Also, grinding the pharyngeal teeth and rubbing the pectoral spines against the chest corset can produce sound. Both of these mechanisms appear as a fear response developed by hardhead catfish. Some argue that hardhead catfish uses an unpolished sonar form as an echolocation device, which also implies some targeted listening capabilities. That's possible, but so far unproven, the voice was used in courtship and spawning.
Life cycle and reproduction
Catfish hardheads have a reproductive season from about May to September. Men and women reach sexual maturity before age 2. Women in adults are about 12.6 to 26.5 centimeters (5.0-10.4 inches), and the average man is slightly larger, usually about 25 cm (9.8 inch). At maturity, females develop a fatty tissue like a flap by their abdominal fins, which causes them to have larger abdominal fins than men. It has been suggested that these improved abdominal fins are the place of fertilization and that they play a part in transferring a fertilized egg to a male mouthbrooder for incubation. Another possibility is that men take eggs from depressions in the sand, because eggs tend to be demersal. They also died after 4 years.
Parental care
Mouthbrooding
Like other members of the Ariidae family, the hardhead catfish is the hammer of the mouth. After spawning, the males will carry the eggs in their mouths until they hatch. There are some eggs that do not work in the parent attached to the larger and feasible eggs. It has been speculated that these non-functioning eggs are used as food for mouthbrooder men, because mouthbrooders do not feed while they are caring for their mothers.. Oral incubation continues through the larval state of the yolk sac, for a total length of about 8-11 weeks. Under laboratory conditions, the offspring can hatch in about 30 days. Her offspring have a length of about 6-8 centimeters and slowly adapt to adult behavior, such as under eye feeding and scavenging. In the absorption of yolk sacs, adolescents begin to show adult characteristics. Male parents can choose to bring the young after they hatch until they are bigger and able to survive on their own.
Benefits
There are many advantages to mouthbrooding compared to other forms of parental care, such as bubblenesting. Mouthbreeders can move freely with eggs in their mouths, and thus, can move as necessary to protect themselves and their mothers. Although mouthbrooding requires more energy by men, there is also a greater possibility of young survivors, and therefore, reproducing and continuing their genes; eggs are helpless when in the mouth of their father. Mouthbrooding by men against the relatively low fecundity of females, which has only 20-65 eggs per spawning episode. Finally, through the breathing, the males are able to keep the mother oxygenated, which also improves the parent's survival.
Fishing
Catfish Hardhead is a greedy feeder and will bite almost all natural baits. Catfish Hardhead is also known to steal bait. Shrimp is a very effective bait to use. When fishing for this species in fresh water, various kinds of meat tend to work best as bait. For example: bacon, chicken, steak cuts, and smaller fish. The Hardhead catfish is generally considered to be an unintended catch by most anglers, this may be largely due to the risks associated with handling venomous fish as well as a 'fishy' taste compared to the desired game. Hook size 1 is usually effective for catching this fish. Anglers usually use lightweight tackles if they are fishing specifically for this species, but many use heavyweight tackles because hardhead catfish seem to bite equally well on both. Care must be taken in handling catfish hardheads because the mucus on their thorns is a bit venomous. If the skin is punctured, pain and swelling will occur, and infection may occur. The spiny spine, which makes the withdrawal more unpleasant.
Catfish Hardhead can be eaten but, like all catfish, it needs effort to clean it up. It is one of the thirty most-harvested species on a recreational basis in the 5-county area (Volusia, Brevard, Indian River, St. Lucie, Martin) encompassing the Indian River Lagoon (IRL) in central Florida. From 1997-2001, 361,022 catfish hardheads were harvested within 200 miles of the coast in the IRL region.
Hardheads are also harvested for industrial use in commercial trawl operations. The annual harvest varies greatly, but from 1987-2001, 1.04 million pounds of sea catfish (including catfish hardhead and gafftopsail catfish) are harvested in the IRL region. The harvest was priced at $ 777,497.
Weight and length
The hardhead catfish has an average weight of 1 Â £ (0.45 kg) and measures 10 to 12 in (25-30 cm) in length.
When the catheter hardhead grows longer, they grow heavier. The relationship between length and weight is not linear. The relationship between total length (L, in inches) and total weight (W, in pounds) for almost all species of fish can be expressed by the form equation:
Typically, b is close to 3.0 for all species, and c is a constant that varies among species. The relationship described in this section shows that the deephead catfish (51 cm) will weigh about 3 lb (1.4 kg), while the 25 'in (64 cm) hardhead catfish is likely to weigh at least 6 lb (2.7 kg)..
References
External links
- Smithsonian Marine Station at Fort Pierce
Source of the article : Wikipedia
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