If you stroll along the coasts of Monte Hermoso, Pehuén-Co, or Claromecó, you'll likely hear about a rather peculiar creature that moves in the depths. It's the fiddler fish , also popularly known as the guitarfish, and although it goes unnoticed by many, it's a key element in maintaining the marine ecosystem.
Unfortunately, this species is in a very precarious situation, bordering on critically endangered . While for some fishermen it is a coveted trophy due to the fight it puts up on the hook, for the scientific community it represents an urgent conservation challenge in the waters of the Southwest Atlantic, encompassing territories of Argentina, Uruguay, and Brazil.
Morphology and distinctive features
At first glance, the guitarfish is a true evolutionary puzzle. Its shape resembles a guitar or a violin, combining the best of both worlds: the front part is very similar to a ray, while the rear section is purely shark-like. Its snout is long and pointed, and it has tough skin with a row of spines down the center.
As for their colors, the back usually ranges from grayish-brown to yellowish , sometimes with blue spots on an olive background, while the belly is white. Depending on the species, such as Rhinobatos rhinobatos , they can reach a meter in length, although there are varieties that exceed one and a half meters or even weigh up to 11 kilos.
Habitat and food
These animals are solitary and prefer to live on sandy and muddy bottoms , generally moving at depths ranging from one meter to 110 meters. They are widely distributed throughout the eastern Atlantic, the Mediterranean, and especially in the southern part of the American continent.
Its diet is that of a benthic apex predator, meaning it eats everything it finds on the seabed: crustaceans, mollusks, marine worms , and small fish. What's most interesting is its feeding method; by stirring up the sediment with its snout and fins, it acts as a natural bioturbator , oxygenating the seabed and releasing prey for other species, thus maintaining the balance of the underwater ecosystem.
A fragile and complex life cycle
Guitarfish don't grow up quickly, and therein lies part of their vulnerability. Females take between 7 and 9 years to reach sexual maturity , while males do so slightly earlier, around 5 or 6 years old. They are viviparous (or ovoviviparous, depending on the species) animals that reproduce only once a year, with small litters of between 4 and 12 pups.
During gestation, the embryos depend on the egg's reserves, a slow process that makes each adult female vital for the species' survival. Interestingly, although embryos measuring around 10 cm have been found on the Buenos Aires coast, scientists have yet to pinpoint the exact moment of hatching, a mystery that remains unsolved.
The fight against extinction and responsible fishing
For years, this fish was caught without regard for human safety. Although not the primary target of industrial fishing, it is often caught in shrimp trawls or sought after by recreational fishermen who value its meat and resilience. In Brazil, the population plummeted by 96% in just one decade, a truly alarming figure.
To stem this decline, bold measures have been implemented. For example, in the renowned 24-Hour Black Corvina Tournament , guitarfish are now banned from competition, requiring anglers to release them back into the water. This change has been made possible thanks to the work of experts like Andrés Jaureguizar and other biologists who have helped anglers shift their perspective from hunters to allies.
Citizen science: the role of the fisherman
Today, a very ingenious citizen science system has been implemented . Using QR codes, anglers who catch a specimen can record data such as size, sex, and water temperature before releasing it. This collaboration is crucial for understanding the migratory routes and behaviors of chondrichthyes (sharks and rays).
All this effort to raise awareness and disseminate information has culminated in the documentary Fishermen & Guitars , which aims to change society's relationship with the ocean. The idea is clear: if we don't take care of these animals, the coastal ecosystem will change drastically, because, as the researchers say, without guitars there's no rock and roll.
The survival of the fiddler fish now depends on a coordinated effort between science and the community. From legal protections in the Mediterranean to release campaigns in Argentina, the goal is to preserve this biodigester of the seabed . A combination of stricter laws, education for fishing enthusiasts, and scientific monitoring is the only way to prevent this unique hybrid between a ray and a shark from disappearing completely from our seas.