The rotting body of a dead Amazon “river monster” recently washed ashore in Florida, which according to news sources raises concerns about whether this giant predatory fish has joined the ever-growing list of invasive species at the Sunshine State.
But while it can thrive in the warm waters of Florida, this fish, known as the arapaima (Arapaima gigas) – a substantial creature that can grow 3 meters long and up to 440 pounds. (200 kilograms), according to a 2019 study in the journal PLOS Een The odds are against it, at least for now, said Solomon David, a water ecologist at Nicholls State University in Louisiana, who was not involved in the recent arapaima observation.
This is because these fish have very specific peculiarities: they breed only in specific areas, spend precious time and energy caring for their young, and do not reach sexual maturity until they are about 1.5 meters long and at least 3 meters long. up to 5 years old, David told WordsSideKick. In addition, many individuals will need a sustainable population in Florida, and so far only one dead arapaima has been found.
In this case, the arapaima was probably an exotic pet in the private aquarium of a person who had either become too large for his tank. illegally released died in the wild or in captivity and was dumped into the river, David said. “We do not even know if this thing lived when it was dumped, or if it was dumped there,” David told WordsSideKick.
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The remains of the arapaima were found in Cape Coral’s Jaycee Park on the banks of the Caloosahatchee River, which empties into the Gulf of Mexico in western Florida, the South Florida Sun Sentinel reported in early March. The normally greenish fish, which has a reddish tail, has already turned white from decay. show photos. But while it was not the full 10 feet long, it was definitely an arapaima, the Fish and Wildlife Conservation Commission in Florida told the Sun Sentinel.
This fish, also known as the pirarucu or paiche, was previously abundant in parts of the Amazon River, but the species is now endangered in many places along its original habitat, David said. The arapaima is part of the bony tongue group, a series of tropical trout with a heavy body whose tongues are studded with teeth and whose bodies are covered with large, mosaic-like scales that are hard, like harness, according to the Encyclopedia Britannica. This scale is so tough, even piranha’s can not bite through them – but that’s just luck, because the arapaima evolved long before piranhas even existed, David said.
The arapaima is valued for its meat, and not only in rural areas along the river, where the fish’s relatively deboned meat, once salted, can be stored without refrigeration, according to Miami Patch. In fact, Whole Foods Market sold arapaima, the grocery chain, commercially said in a blog post from 2016. But wild arapaima are largely threatened by overfishing, and it does not help that the species, one of the largest freshwater fish in the world, is relatively easy to spot. It is a mandatory air vent, which means that it must come to the water surface every 5 to 15 minutes to swallow into the air, according to a 2009 study in the Journal of Applied Ichtheology.
Arapaimas developed this breathing tactic because the Amazon is low oxygen levels. (Hot water contains less oxygen than cold water.) Arapaimas have no lungs, but rather special tissue in their oxygen-processing swimming pools, Lesley de Souza, a conservationist specializing in neotropic fish at the Field Museum in Chicago, told mongabay.com.
Related: Image Gallery: Invasive Species
Invested parents
Unlike many fish that never meet their young, arapaima are loving parents. During the Amazon rainy season, usually from December to May, the river overflows into neighboring floodplains. It is there, on the flooded plains, that arapaimas dig shallow nests where the females can lay eggs for the male to fertilize. Both parents protect the nest from predators, and they continue to care for the young as soon as the eggs hatch just nine days later, according to a 2017 study in the journal. PLOS Een.
Both parents release a milk substance from their heads, known as ‘arapaima milk’, which is fed to the offspring, according to the study. In addition, the fathers are dedicated caregivers.
“The male provides intensive parental care that can last up to three months, which can lead the offspring to feed above his darkened head in zooplankton – rich areas,” according to the 2017 study. male and young to swim – it’s not clear why, but perhaps to be looking for predators or food – and usually leaves her “family” after about a month, after which she reproduces with other males. according to the study.
Parental care is a major reason why arapaimas are unlikely to take in the waters of Florida, as young arapaimas ‘are not very tough fish when they are small,’ David said. But when these fish reach adulthood, they can live at least 15 to 20 years, according to the 2019 PLOS One study.
Granted, although the odds are high against this fish in Florida, the arapaima can overcome these obstacles – perhaps they can find breeding grounds off the coast of Florida, raise their young, wait until they are big and old enough to reproduce and then the cycle, the establishment of a viable population. If that were to happen, these greedy eaters would likely make a dive into populations of both invasive and native fish species and small invertebrates that live in the area, David said. However, these fish are so large and it takes so long to mature that it will probably be possible for the Florida Fish and Wildlife Conservation Commission to locate and remove them, he noted.
“We have to be careful – there is nothing wrong with being vigilant,” David said. “But this is not the best way to go from fish to fear,” he adds, noting all the negative media coverage these fish get.
Some outlets, including CBS and even the fishing magazine “Field and stream, “called the Amazon fish” ugly. “
“As someone who’s kind of an ‘ugly’ fish, I think we need to get away from it,” David said. Just look at the red scales. “
Originally published on Live Science.