1. RAYS AND SKATES UPCLOSE! Orange High School Library

2. Rays and Skates Upclose! Ray and Skate Basics Ray and Skate Biology Ray and Skate Conservation Ray and Skate Research

3. RAY AND SKATE BASICS

4. What is a ray? Rays are dorsoventrally flattened fish that are closely related to sharks. All are considered to be within a closely related group of fish called elasmobranchs. Rays belong to three scientific orders - Pristiformes, Myliobatiformes, and Torpediniformes © George Ryschkewitsch

5. What is a skate? Skates are dorsoventrally flattened fish that are closely related to sharks. All are considered to be within a closely related group of fish called elasmobranchs. Skates are classified in the order Rajiformes. © George Burgess

6. Stingrays are a type of ray, however not all rays are stingrays as this group also includes electric rays, butterfly rays, round rays, manta rays, guitarfish, and sawfish. Are all rays considered stingrays?

7. How many species of rays and skates are there? There are approximately 500 different species of rays and skates that are divided into 18 families when scientifically classified.

8. What are the differences between rays and skates? The major difference between rays and skates is in their reproductive strategies. Rays are live bearing (viviparous) while skates are egg laying (oviparous), releasing their eggs in hard rectangular cases sometimes called "mermaid´s purses".

9. How long have rays and skates existed? The fossil record of rays and skates dates back to the Lower Jurassic (150 million years ago). U.S. National Park Service

10. Do rays and skates have bones? Rays and skates have no bones, but instead have skeletons made of cartilage as do sharks. Cartilage is tough and fibrous but not as hard as true bones. © Cathleen Bester

11. How do rays and skates swim? These unique animals swim through the water by gracefully undulating the modified pectoral fins, appearing to fly through the water. They sometimes make spectacular leaps from the surface of the water. © Doug Perrine

12. Are stingrays dangerous to people? Stingrays have venomous spines along or near the base of the tail. The muscular whip-like tail can be lashed about quickly in defense. Occasionally beach-goers will accidentally step on stingrays that are partially buried in the sand near the beach resulting in a painful, serious wound in the foot. © Cathleen Bester

13. Where do rays and skates live? Rays and skates live in oceans throughout the world. Most rays and skates are benthic while some are pelagic. Some rays live in freshwater habitats

14. Can rays and skates live in freshwater? In Florida, the Atlantic stingray (Dasyatis sabina) is known to live in freshwater along the St. Johns River waterway as well as inland freshwater lakes. These populations of the Atlantic stingray are unique in that they spend their entire lifecycle in freshwater. © Doug Perrine

15. RAY AND SKATE BIOLOGY © Tobey Curtis

16. What are some adaptions of rays and skates? The dorso-ventrally flattened bodies allow rays and skates to glide closely over the bottom sediments in search of prey. Their eyes and spiracles are positioned on the top of the head, allowing them to take in water for respiration while partially buried in the sand. The mouth is located on the underside of the animal as an adaptation for feeding on benthic invertebrates and fishes. © George Burgess

17. What does ray and skate skin feel like? The skin feels exactly like sandpaper because it is made up of tiny teeth-like structures called dermal denticles. Skate skin may also possess thorns which help to defend them from predators.

18. Do rays and skates have good vision? The eyes of rays and skates are located dorsally, on the upper surface of the animal, while the mouth is located on the underside. It is believed that vision may play only a secondary role in prey location and feeding behaviors. © Doug Perrine

19. How do rays and skates detect prey? Rays and skates use the senses of smell (chemoreception), vision, hearing, the lateral line system, and electroreception (ampullae of Lorenzini) for capturing prey. The lateral line system, which most fish possess, allows them to detect waves of pressure or mechanical disturbances in the water. © George Burgess Ampullae of Lorenzini on a sandbar shark

20. What do rays and skates eat? The majority of rays and skates feed on bottom dwelling (benthic) animals including shrimps, crabs, oysters, clams and other invertebrates. Some rays such as the manta and devil rays are filter feeders relying on plankton as their food source.

21. Do rays and skates have any predators? Sharks, in particular hammerheads, often have spines in their digestive tracts and imbedded in their jaws from feeding on stingrays. © George Burgess

22. How can you distinguish a male from a female ray or skate? Male rays and skates (as well as sharks) have claspers while females do not. Claspers are modifications of the pelvic fins and located on the inner margin of the pelvic fins. They are used to transfer sperm to the female during mating.

23. Do rays and skates give live birth or lay eggs? Rays give live birth while skates lay eggs in egg cases (as pictured above) referred to as "mermaid's purses". © George Burgess

24. Do rays and skates take care of their young? Neither rays or skates exhibit parental care other than moving to a protective area to lay eggs or give birth. © James Sulikowski

25. RAY AND SKATE RESEARCH © Christina Conrath

26. Tagging and tracking rays in some of the waterways along the coast of Florida. The data from this project will assist in the identification of daily and seasonal movements of rays. The reproductive biology of skates and the feeding ecology of rays and skates in the Pacific Ocean. The age and growth of a skate species that has declined more than 95% due to take as bycatch in the New England groundfisheries. What are some current ray and skate-related research projects? © Christina Conrath

27. RAY AND SKATE CONSERVATION © Doug Perrine

28. Are rays and skates threatened or endangered? Unfortunately, there are many species of rays and skates that are considered threatened and endangered. The IUCN Red List includes 547 species of elasmobranchs of which at least 20% are in danger of extinction.

29. Further Information: http://www.flmnh.ufl.edu/fish/Education/education.htm Orange High School Library