Manta Ray Presentation (2012)
Transcription
Manta Ray Presentation (2012)
Manta Rays What are Manta Rays? Cartilaginous Elasmobranch Fish • 1050 Species - 500 Species of Sharks - 550 Species of Rays • • • • 400 Million Years Old Skeleton Made of Cartilage Internal Reproduction 5-7 Gill Slits 160 million year old Blanket Ray 370 million year old shark called Cladoselache Great White Shark Rays of the World Huge variety and abundance of species 260 Skates 45 Guitarfishes 180 Stingrays Majority are bottom dwellers with broad flattened bodies Spotted Eagle Ray A few species took to the open water 70 Electric Rays Manta & Mobula Rays 11 species in the Mobulidae sub-family Sickle-fin Mobula Ray Reef Manta Ray All are filter feeders with forward facing mouths Smooth-tail Mobula Ray First appeared in the fossil record only 20 million years ago Oceanic Manta Ray Species Identification Reef Resident Manta Ray Giant Oceanic Manta Ray Manta Facts Global Distribution Largest Ever Recorded Manta: Width = 6.8m (22ft) & Weight = 2,000kg A 6m Giant Manta Ray caught in 1933 off New Jersey, USA Two Colour Morphs: Black Vs Chevron Manta Feeding Huge mouths and gills filter out the tiny planktonic animals from the water Chain Feeding Planktonic Mysid Shrimp Mass Feeding Manta Cleaning A manta opens its mouth wide for the dentist Cleaner Wrasse A group of manta rays hover over the cleaning station Manta Predators Orca or Killer Whale Tiger Shark Shark Bite Injuries Wound Healing Sexual Dimorphism Immature Male Mature Male Larger Female Manta Mating Mating Train Copulation Manta Birthing Females give birth to just one (1.5m), fully independent pup after a year long pregnancy A heavily pregnant female visits a cleaning station Unborn Manta Pup Manta Teeth Female’s Mating Scars Threats to Manta Rays By-Catch Gill Nets Shark Fishing Nets Mooring Buoys Tuna PurseSeine Net Fisheries Gill Nets Manta Fisheries Africa Mexico Manta & Mobula Ray fisheries around the world are decimating populations Sri Lanka Indonesia Gill Rakers WHY?? New demand from Asia for the mantas dried gill rakers used in traditional medicines Global Protection Manta Rays are listed as “Vulnerable” by the World Conservation Union Some countries have taken their own steps to protect Manta Rays In Hawaii Manta Rays are protected by state law & in the Maldives there is an export ban on all rays which prevents any form of commercial fisheries Through tourism, Manta Rays generate US$8.1 million in direct revenue for the Maldivian economy each year The Manta Trust www.mantatrust.org Conservation through Research, Awareness and Education UK Registered Charity Number: (1145387) Our Vision: A world where manta rays thrive within a globally healthy marine ecosystem. Our Mission: The Manta Trust works to advance the worldwide conservation of manta rays and their habitat through robust science and research, raising awareness, providing education, influence and action. Projects: Currently the Manta Trust has projects in the Maldives, Sri Lanka, India, Indonesia, Mexico, Hawaii, Fiji, The Mariana Islands & The Line Islands. Thank You!