Stingrays are a group of sea rays, which are cartilaginous fish related to sharks. Many species are endangered. They consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deepwater stingray), Urolophidae (stingarees), Urotrygonidae (round rays), Dasyatidae (whiptail stingrays), Potamotrygonidae (river stingrays), Gymnuridae (butterfly rays), and Myliobatidae (eagle rays).
Stingrays are some of the most beautiful, mysterious-looking creatures to inhabit the ocean. Stingrays represent an important part of the food web by providing a link between apex predators and lower trophic levels. Generally docile, these cartilaginous fish are closely related to sharks.
Being fish, they don’t breathe air, but instead they have gills allowing them to respire underwater. To breathe they must continually keep water flowing over their gills.
Despite their misleading size, some rays like the Manta feed on some of the smallest organisms in the sea! These are planktivores, feeding on the plankton that is found in the water column. Other stingrays are purely carnivorous and they like to eat animals smaller than themselves. In particular, they like to eat animals that live on or beneath the sand like worms, clams, oysters, snails and shrimp.
Stingrays are not aggressive by any means, and injuries are rarely fatal. The stingray's defense mechanism consists of a serrated barb at the end of its tail with venom glands located at the base of the barb. The venom is a variable mixture of substances, none of which are specific to the animal; therefore, the creation of antivenom is not possible. Stingrays will strike when threatened or stepped on. The barb can easily tear wetsuits and penetrate skin and may cause deep, painful lacerations.
Longheaded Eagle Ray
Mottled Eagle Ray
Ornate Eagle Ray
Purple Eagle Ray
Giant Devil Ray
Brazilian Cownose Ray
Below are a few well-known Stingray species classified as Vulnerable.
Reef Manta Ray
Giant Manta ray
Banded Eagle Ray
Spotted Shovelnose Ray
Threats to Rays
Stingray species are progressively becoming threatened or vulnerable to extinction, particularly as the consequence of unregulated commercial and recreational fishing pressures, the impact of non-ray fisheries on the seabed and ray prey species, and other habitat alterations such as damage and loss from coastal development and marine pollution.
Rays reproduce slowly. Some mantas don’t reach sexual maturity until they’re 15 years old, and even then they only typically have one pup every two to five years. This means that they can’t bounce back from the decimation wrought by overfishing. They are literally being pulled from the oceans faster than they can reproduce. Even with the strictest protections, it will take decades for manta rays to recover from the unsustainable overexploitation they have experienced.
Stingray wing is popular in many cultures and considered a delicacy around the world. Rays are edible, and may be caught as food using fishing lines or spears. Stingray recipes abound throughout the world, with dried forms of the wings being most common. For example, in Malaysia and Singapore, stingray is commonly grilled over charcoal, then served with spicy sambal sauce, or soy sauce. Generally, the most prized parts of the stingray are the wings, the "cheek" (the area surrounding the eyes), and the liver. The rest of the ray is considered too rubbery to have any culinary uses.
Stingray skin is used as an under layer for the cord or leather wrap (known as ito in Japanese) on Japanese swords due to its hard, rough, skin texture that keeps the braided wrap from sliding on the handle during use. They are also used to make exotic shoes, boots, belts, wallets, jackets, and cellphone cases.
Stingray gill plates are exploited for the unsupported, recent belief in Chinese medicine that eating dried and crushed manta ray gill plates detoxifies human blood and aids in curing everything from chicken pox to cancer. Ray gill plates can be worth more than $300, and a mature giant manta ray can yield up to 15 pounds of dried gill plates. As other valuable fish stocks become depleted, fishermen are now tapping into mantas, targeting them not only for their gill plates, but also as a cheap substitute or filler for shark fin soup.
Bycatch refers to the animals fishers catch incidentally while fishing for a different species. For example, if a fishing boat catches stingrays while fishing for swordfish, the ray is considered to be bycatch. Entanglementin commercial fishing and aquaculture gear can cause significant injuries to rays, affecting their ability to swim and feed. Rays can also be immobilized by fishing gear such as crab and prawn traps, causing them to suffocate and drown.
Climate change affects the amount of plankton in the ocean, which is a big problem for a rays that feeds exclusively on these tiny sea creatures. Rays rely on coral reefs, which make up only 0.2% of the marine environment, but house 25% of all marine life. The fish species that live around reefs provide “cleaning stations,” where they help rid the rays of parasites – a process that can take up to eight hours, but benefits both the ray and the fish. Coral reefs also serve as important feeding and breeding locations for rays. Yet as coral reefs are quickly disappearing due to climate change, rays are losing this vital habitat.