Ray migration

Image Source: Wikimedia

Victoria Navas Via-Dufresne
Staff Writer


Cownose rays, a highly venomous species of ray known for the dome-like structure on their heads, are a kind of ray that is in constant movement.

This species of stingray migrates in groups of 10 000 individuals. The large number of rays makes it look like a wave in the ocean. They can be found between Brazil and southern New England where the waters are warmer. These rays can live up to 13 years and can reach a length of 1.9 meters. Instead of staying on the ocean ground, these rays keep moving.

This type of ray, although very large, isn’t the largest. The Manta Ray can reach a length of 7 meters. Manta Rays live also around the equator where the ocean water is usually warmer. They eat plankton, fish eggs and occasionally some small fish. Unlike the cownose stingrays, the oceanic Manta ray migrate very little staying close to their original home. They can move up to 220km away from their usual patches of ocean. Depending on their original location, they have different dietary and genetic adaptations.

Many ray species are listed as vulnerable since they are hunted for their gills. Two agreements protect oceanic mantas to this day: CITES, banning the trade of products derived from mantas, and the Convention on Migratory Species.

A reef manta ray called manta alfredi lives in the Indonesia region and is a small species of manta ray. These manta rays are subject to hunting. While these rays live in sanctuaries, they are proof that the protection treaties don’t always work properly, showing flaws in our ocean protection systems. 

Originally Published on www.bandersnatch.ca Vol.49 Issue 11 on March 18th, 2020