Caribbean electric ray

2/19/2016

I think it’s safe to say that the ocean harbors some of the most interesting animals on the planet. From the beautifully colored and deadly mantis shrimp to the covert scorpion fish, and the small guppies, we’ve got it all. We’ve even got some… shocking… individuals.

If you live in the coastal waters of the Atlantic Ocean, around the eastern shores of the US, the Gulf of Mexico and down the eastern coast of Central/South America, you might have snorkeled by these animals. They’ve been seen in the Pacific Ocean, too! They frequent shallow, coastal waters and like to bury beneath the sand or mud to hide from predators, like sharks. They might have swum by your foot, as they sometimes are seen in seagrass beds.

If you’re wondering what this mysterious animal is, let me formally introduce you to the Caribbean electric ray (Narcine bancroftii), order Torpediniformes. Quick fact: There are 69 species of electric ray in four families.

This ray looks a lot like the yellow stingray, with a round body and short tail. Their dorsal pigmentation varies from dark to light brown, with irregular rings/ovals. They lack a spine because why have one when you have electric organs? Not that you can see them if you’re staring down at them- you have to flip these critters over to see two kidney-shaped organs above the gills, by the mouth. Not that I would want to handle an electric animal… underwater… no thanks, I’ll pass.

Also similar to the yellow stingray, these are small animals. The males usually get no larger than 86 cm (around 33 in) from the tip of their snout to the end of the tail (total length). Females are smaller, only getting up to 66 cm (26 in).

Not a lot is known about the biology of these animals. But, don’t worry, these animals don’t deliver electric charge shocks willy-nilly.

“Oh, yes, glorious day to bring my shocking count up to 200… oh, look, a worm. Let me shock it.”
~ZAP~
“Marvelous. Next, that plant.”
~ZAP~
“And now this rock. To make me feel powerful and almighty.”
~ZZZAAAPPP~

Instead, they create a strong charge to stun their prey or defend themselves (aka handle them with caution). They have a zapping organ on either side of their body, making it so that their prey is trapped… and eventually eaten. Gloriously evil and smart... my favorite kind of super villain mixture.

The shock isn't meant for us (their prey upon marine worms, baby snake eels, anemones, small bony fish, crustaceans, etc.), but they have been known to knock humans down with their electric shocks. This shock can vary between 8 volts and 220 volts, depending on the species. Electric rays are viviparous with yolk-sac and reproduce slowly with a doubling time estimated to be between 4.5 and 14 years.

The IUCN has listed this critter as Critically Endangered (CR). There are no known conservation measures currently in place for this species. And although there are gaping holes in the understanding of this fascinating animal, they certainly are not animals you want to accidentally startle. Ouch!

REFERENCES

Vianna, G.M.S. and Vooren, C.M. (2009) Distribution and abundance of the lesser electric ray Narcine brasiliensis (Olfers, 1831) (Elasmobranchii: Narcinidae) in southern Brazil in relation to environmental factors. Brazilian Journal of Oceanography, 57(2): 105 - 112.
Rudloe, A. (1989) Habitat preferences, movement, size frequency patterns and reproductive seasonality of the lesser electric ray, Narcine brasiliensis. Northeast Gulf Science, 10(2): 103 - 112.
Dean, M.N. and Motta, P.J. (2004) Feeding behavior and kinematics of the lesser electric ray, Narcine brasiliensis (Elasmobranchii: Batoidea). Zoology, 107: 171 - 189.
Campbell, A. and Dawes, J. (2004) Encyclopedia of Underwater Life. Oxford University Press, Oxford.
Lesser Electric Ray Biological Profile, Ichthyology Department, Florida Museum of Natural History (July, 2009)

thoughts on this electric ray?

glossary

Crustaceans: Group of animals with a hard exoskeleton, jointed legs and segmented body.
Dorsal side: Top side of an animal.
IUCN: International Union for Conservation of Nature.
Viviparous with yolk-sac: Also known as aplacental viviparous and previously known as ovoviviparous/ovoviviparity; it is the production of eggs that are fertilised and hatch inside the female shark but the embryos lack a placental connection to the oviduct or uterus and so do not feed off the mother.