El trout fish, also known as torpedo fish or scrapie, is a fascinating species that is distinguished by its ability to generate electric shock for hunting and defense. Belonging to the family Torpedinidae, this torpedo-like elasmobranch is widely distributed in temperate and tropical waters around the world, especially in the Atlantic Ocean and the Mediterranean Sea.
Physical characteristics of the Tremielga
La tremielga presents a body dorsoventrally flattened, with a fleshy disk with rounded edges formed by the fusion of its body with the pectoral fins. This disk allows it camouflage on the seabed, burying themselves in the sand or mud with only their eyes and spiracles visible.
- Size and weight: It can reach up to 70cm length and an approximate weight of 5 kg.
- Form: Its body is almost circular and has a robust tail with a well-developed caudal fin.
- Fins: Owns two pectoral fins fused with the body, two dorsal fins on the middorsal line and pelvic fins rounded, joined to the front of the tail.
- Coloration: Its back varies between brown and cream, with dark spots that give it a marbled appearance, while its belly is completely whitish.
Electric organs and discharges
One of the most distinctive characteristics of the tremielga is its ability to generate electric shock through two specific organs located at the front of the disk, on each side of the head. These organs, called electroplasts, allow you to produce downloads of 50 to 220 volts and to 1 amp, used both for hunting and for defense against possible predators.
Even the newborn babies They develop this ability, generating discharges of approximately 4 volts. These electrical pulses can reach a frequency of up to 600 Hz, which allows them paralyze their prey effectively.
Habitat and behavior
The tremielga lives mainly in sandy or muddy bottoms of temperate and tropical seas, from shallow depths to the 370 meters, although it usually moves between the 2 and 20 meters. Their behavior is mostly night; during the day it remains buried in the marine substrate with only its eyes and spiracles visible.
- Distribution: It is in the Atlantic Ocean from the north of Scotland to South Africa and in the Mediterranean Sea.
- Movements: It's a fish solitary and slow-moving, but when it feels threatened, it swims by undulating the edges of its pectoral fins, which allows it to glide through the water.
- Adaptations: Its coloring allows it camouflage oneself effectively in its environment, being difficult to detect for both prey and predators.
Feeding of the Tremielga
This fish is a nocturnal predator which feeds mainly on Crustaceans, mollusks and benthic fish. Their hunting strategy consists of paralyze their prey with an electric shock before swallowing them whole.
Its usual prey includes:
- Benthic fish , the Trachurus, Mugil, Mullus, Dicentrarchus y Boops.
- Seafood small in size.
- Squid and other cephalopods.
Reproduction and life cycle
The tremielga is a fish ovoviviparous, which means that the offspring develop inside the mother until the moment of birth. Fertilization is intern, and the embryos initially feed on the yolk of the egg, subsequently receiving additional nutrients from the mother through a uterine fluid enriched with mucus, fat and proteins.
- Duration of gestation: Between 8 and 10 months.
- Number of pups per litter: Between 5 and 32, with a birth size of 10 to 14 cm.
- Time of birth: It usually occurs between september and december at the Mediterranean Sea.
From the moment of their birth, the offspring are already capable of generating electric shock to defend themselves and hunt small prey.
Relationship with humans and fishing
The tremielga does not have a significant commercial value, since its meat is not appreciated in gastronomy. However, it is occasionally captured as bycatch using trawl nets, trammel nets or bottom longlines.
In ancient times, the Romans used the electrical properties of this fish to treat diseases such as rheumatism. Currently, its electric organ is studied in biomedical research due to its relationship with neurotransmitters.
For its ability to produce electric shock, it is advisable to avoid direct contact with this fish when diving or accidentally handling it, since its discharge can be painful although does not represent a serious danger for humans.
The tremielga is a fish endowed with a unique ability in the animal kingdom. Despite its harmless appearance and limited mobility, its ability to generate electricity makes it an efficient predator and a fascinating species in the oceans.