There are fish that get their name from the way they look, as with the stone fish, and because they resemble other animals, such as the Roosterfish. This is the case of crocodile fish. As its name suggests, it is a fish that looks very similar to that of a crocodile. Its scientific name is atractosteus spatulaHe is famous, not only for his looks, but because he has the ability to get in and out of the waterIt can stay out of the water for up to two hours without any problems. It truly is a curious fish worth getting to know.
In this article we are going to explain everything about this crocodile fish, from its main features to its diet and reproduction, with additional details on its classification, habitat and conservation that will help you better understand this unique species.
Key features
The ability of this fish to enter and exit the water It is fantastic because it gives them great versatility in their life. Fish are limited to the aquatic environment and, even if there is food nearby, the fact that it is out of the water already prevents them from accessing it; in the case of the crocodile fish, its modified swim bladder It functions as an accessory respiratory organ, allowing you to breathe air when dissolved oxygen is scarce.
The crocodile appearance is more pronounced in the face, since it has an elongated snout and a shorter lower jaw. It is quite large in size, reaching almost 3 meters long and weighing around 200 kilos in exceptional specimens. There are actually people who have seen them and mistaken them for real crocodiles. Females usually have a bigger size that of the male, as in many other species de peces, a trait that is associated with higher fertility.
The color of your skin is olive brown on top and a more yellowish white on its underside. Come on, it looks similar to a whole crocodile. In addition, its cylindrical body is covered by ganoid scales (hard, rhombus-shaped) that act as armor. It has fins with brown spots and some individuals show a thin, clear line along the flanks. The upper jaw has two rows of teeth, a feature that distinguishes it from other lepisosteids.
There is no single explanation for this similarity. Reptiles and fish do not share many characteristics for these two species to look so similar, but this is a classic case of convergent evolution: similar body shapes in animals that occupy ecological niches similar, such as that of an ambush predator.
As a taxonomic note, the crocodile fish belongs to the class Actinopterygii, order Lepisosteiformes and family LepisosteidaeIn many places it is also known as alligator garThis family includes the so-called "lizard fish", and the crocodile fish is the bigger of all of them.
Range and habitat
The crocodile fish usually inhabit large lakes, rivers and some swamps. They live in fresh water, although they can also tolerate brackish waters (brackish) in estuaries. Its distribution area covers large areas of North America within the region Neoarctic. It can be found in mouths of rivers such as the Ohio and Mississippi, as well as in the river network that drains towards the northern coast of the Gulf of MexicoIts natural limit includes areas close to the Great Lakes, such as the mouths of the Lake Michigan and Lake Erie, although its stable presence is more associated with basins with temperate waters.
It also lives in huge lakes like the Ireland and the Michigan (known for being some of the largest lakes in the world) and in areas such as Alabama, Tennessee, Arkansas, Oklahoma, Georgia, Florida, and Texas. It prefers shallower waters to better view its prey. Open waters near the coast are their favorites, since there they have more space to prepare their attack and shelter among the riparian vegetation.
Generally, they move in waters whose depth is between 3 and 5 meters and in some backwaters with stagnant waters. They can also occupy swamps and marshes with abundant vegetation, where juveniles find refuge. Since they are able to stay out of the water for several hours, they are sometimes observed sunbathing near the surface or on shallow banks, next to logs, fallen trees or brush.
Since it is a coastal-oriented species, we will always find it near banks and structures with vegetation cover. It is rare to see them in completely uncovered sites where they have no protection. In ecological terms, it plays the role of apex predator in quiet stretches of rivers and lakes, controlling populations de peces and contributing to the balance of the ecosystem.
Crocodile fish diet
As expected, It is a fish whose diet is solely carnivorous. They love to devour other smaller fish. Although they don't just eat other smaller fish, but when hunger strikes, they'll eat almost anything. They love crustaceans like shrimp and crabs and can eat acuatic birds, turtles and even small ones mammals that venture to the surface of the water.
Even if hunger is pressing and there are not enough resources around you, can eat carrion that you find along the way. Although it is a fish that seems slow due to its size and weight, it is capable of attacking its prey with great speed and precision. Use a strategy of emboscada, similar to pike fish: It remains motionless near the surface, camouflaged by its coloration, and launches rapid lateral attacks taking advantage of its muscles and its elongated snout. lateral line and sharp vision allow him to detect vibrations and movements in murky waters.
In natural environments, it consumes soft-bodied, elongated fish, but it does not disdain hard-scaled species if the prey size allows. It can also prey on schools, especially during concentrations. de peces prey, although it is more common to observe it hunting alone.
Reproduction
This species has a behavior that is not common in other species de peces. For example, they have the habit of a large number of males gather in shallow water (around 1,5 m) and close to vegetation. This is where they stand, one by one, to compete to see who can win the female. We must bear in mind that the females may let more than one male fertilizes the eggs, so the mating system is considered polyandrous at this stage.
When females lay their eggs, they stick to rocks or vegetation to grow. The eggs are of green to reddish color. The mechanism of adhering to substrates is for survival. If they are spotted by other predators and risk being swallowed, they have another even greater defense mechanism: They are poisonous, a trait that is noted in articles about the most poisonous fish on the planetIf another animal ingests the eggs, it will be poisoned; this effect has also been documented for humans, so should not be consumed.
Spawning generally takes place during the warm and dry season. rising waters, with peaks documented from late winter to mid-summer depending on the region, as spawning depends on local factors such as temperature, photoperiod, and flood pulses. They do not have a fixed location; the location can vary. They only need there to be weeds and shallow water.
Fecundity varies with the size of the female and the productivity of the habitat: they have been recorded from a few thousand eggs in certain local counts up to tens of thousands in large females. The time of incubation usually hovers around a week, depending on the temperature. After hatching, there is no parental care and the larvae seek refuge among the dense vegetation.
Fingerling development
When the crocodile fish comes out of the egg, they are small larvae of only 2,5 cm long. They are very fragile and thin. They can move thanks to the movement exerted by the caudal filament which they have as a tail; this filament doesn't last long; it disappears as the larva develops its functional caudal fin. It has no growth problems, as it grows at a high rate. At only 2 years old, we can find specimens of advanced size and with adult behavior in various habitats.
Although females achieve a larger final size, males are capable of grow and mature sooner in many populations, something that can have an impact on a minor life expectancy. Differentiated growth rates by sex have been observed: in juvenile stages, males may grow faster per year than females, and later the trend may reverse, with females continuing to gain size for longer. sexual maturity It comes with size and is influenced by the environment.
These fish have a life expectancy between 25 and 50 yearsDepending on the environmental conditions, they may live longer or shorter. Females generally live longer than males. Due to their size and shape, these animals hardly have any natural predators in their habitat. When they are fry they do have to be careful with the american alligator, since they are particularly fond of young crocodile fish. Other potential predators of larvae and juveniles include piscivorous fish and birds.
Threats and conservation
The crocodile fish is classified globally as minor concern by the IUCN, with large populations in its natural range. However, in some areas it suffers local pressures due to habitat degradation, channeling of rivers, construction of dams that block spawning routes, pollution and overfishing selective breeding of large specimens.
Conservation actions include capture regulations, closed seasons during spawning, protection of humid areas and floodplain restoration. Also explored are breeding programs and restocking in aquaculture to strengthen local populations where decline has been detected, always under scientific and genetic conservation criteria.
Curiosities and behavior
- Resistance out of water: can survive out of water for a long time (up to about two hours) thanks to the fact that it breathes air.
- Natural armor: Its ganoid scales are so hard that they were historically used as an ornamental and protective material.
- Teeth and bite: It has a double row of teeth in the upper jaw, which increases its effectiveness in capturing slippery prey.
- Comestibilidad: Although their meat can be consumed, eggs are toxic if they are ingested and their marketing is limited by market preferences.
As for behavior, it is a ambush predator Normally solitary and slow-moving, it accelerates explosively to capture its prey. In calm waters it can appear peaceful with other large species when not in hunting mode.
Differences with similar species
It is sometimes confused with other lepisosteids, such as the Florida gar (Lepisosteus platyrhincus) or the spotted gar (Lepisosteus oculatus). A field criterion used by ichthyologists compares the distance between the eye and the edge of the gill with the length of the snout: in the crocodile fish this distance is usually greater than two-thirds of the snout, while in smaller species it may be less. In addition, The crocodile fish reaches much larger sizes and has the characteristic double row of teeth in the upper jaw.
Captive and aquarium care
For his potential size, the crocodile fish is not a suitable species for conventional home aquariums. Juveniles can be kept temporarily in large-volume facilities, but their transfer to a public ponds or aquariums of much larger dimensions when they grow up.
If kept in captivity, the system must be spacious and stableFor juveniles, some keepers use tanks between 600 and 900 liters, located in quiet environments and with low currentThe temperature can be maintained between 18 and 30 ° C and the pH in the range 6 to 8It's essential to have secure covers (they breathe air and can jump) and clear areas to avoid impacts when pushing off.
In long-term installations, it is advisable to very large ponds or aquariums with high filtration and stable water quality, and consult guides on reproduction de peces tropical in the aquarium can help. They accept a variety of carnivorous foods (fish, crustaceans, prepared foods), avoiding overfeeding. With proper care, they rarely get sick; in inadequate conditions, their life cycle is shortened and may have spinal problems or damage to the snout due to collisions.
In long-term installations, it is advisable to very large ponds or aquariums with high filtration and stable water quality. They accept a variety of carnivorous foods (fish, crustaceans, prepared foods), avoiding overfeeding. With proper care, they rarely get sick; in inadequate conditions, their life cycle is shortened and may have spinal problems or damage to the snout due to collisions.
I hope that with this information you can learn more about your biology and its relationship with the ecosystem. This species combines primitive traits, surprising adaptations and a key ecological role, which explains why it arouses so much fascination among amateurs and scientists alike.
