Roundel skate
The roundel skate, known scientifically as *Rostroraja texana*, is a species of cartilaginous fish found primarily in the Western Central Atlantic Ocean, particularly in the Gulf of Mexico and near Florida. It is distinguished by its unique appearance, featuring colorful roundels on its pectoral fins, characterized by a blue center surrounded by black and yellow rings. Young roundel skates inhabit shallow bays, while adults prefer deeper waters ranging from 300 to 590 feet. They are known for their solitary feeding habits, preying on shrimp, small fish, crabs, and other crustaceans by gliding over the sandy or muddy seabed and occasionally burying themselves for camouflage.
Roundel skates reproduce by laying leathery eggs, commonly referred to as mermaid's purses, which take six to nine months to hatch. The young skates emerge about 4 inches long and reach maturity within five years, with adults typically growing to around 25 inches in length. Their diamond-shaped bodies feature brown skin on top and white undersides, with a distinctive row of spines along their backs. With a lifespan of seven to nine years, roundel skates are notable for their fascinating adaptations and ecological roles in their marine environments.
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Roundel skate
The roundel skate receives its name from the colorful roundels, or round markings, on its pectoral fins. Each roundel has a blue center with a black ring and a yellow ring around it. This skate is sometimes caught in the nets of fishermen trawling the bottom for shrimp. It is also called the Texas clearnose skate.
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Rajiformes
Family: Rajidae
Genus: Rostroraja
Species: Texana
Roundel skates live in the Western Central Atlantic Ocean in the Gulf of Mexico and near Florida. Young roundel skates live in shallow bays, while the adults move into water 300 to 590 feet (90 to 180 meters) deep. Both young and old glide smoothly over the sandy or muddy sea bottom as they look for food. They may also bury themselves in the bottom so that only their eyes show. When shrimp, small fish, crabs, and other crustacea or small marine (saltwater) creatures are within range, the skates pounce on them. Skates generally live and feed alone.
A young skate hatches from a leathery egg case commonly called a mermaid's purse. The purse is rectangular and has a tendril at each corner to anchor it to a rock or weed on the bottom. The eggs are oblong. A baby skate may share its case with other baby skates or be the only one inside the purse. The skate may take six to nine months to hatch. The young are around 4 inches (11 centimeters) long and reach maturity after five years.
Roundel skates are around 25 inches (63 centimeters) long. Their bodies are diamond-shaped. Like sharks, roundel skates are cartilaginous fish with cartilage skeletons rather than skeletons of bone. Their backs have brown skin, and on each pectoral fin is a round spot called a roundel. Each roundel has a blue center surrounded by black and yellow rings. The undersides of the skates are white. Like the clearnose skate (Rostroraja eglanteria), the sides of the snouts of roundel skates are transparent, or clear. A row of spines runs down the middle of the back of each roundel skate. Each has a fleshy tail with two dorsal fins.
The lifespan of the roundel skate is seven to nine years.
Bibliography
DeValerio, Kate. "Roundel Skate." Florida Museum of Natural History, www.floridamuseum.ufl.edu/discover-fish/species-profiles/raja-texana. Accessed 15 Apr. 2024.
"Rajidae - Skates." PBS, nhpbs.org/wild/rajidae.asp. Accessed 15 Apr. 2024.
"Rostroraja Texana (Chandler, 1921)." Fish Base, fishbase.de/summary/1254. Accessed 15 Apr. 2024.
"Roundel Skates." The IUCN Red List, www.iucnredlist.org/species/161686/201614906. Accessed 15 Apr. 2024.