Ron's Critter of the Day

TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii (sharks and rays)
Order: Rajiformes (Skates and rays)
Family: Myliobatidae (Cownose and Manta Rays)

Genus/species: Rhinoptera javanica

GENERAL CHARACTERISTICS: R. javanica is a cartilaginous fish with bat-like, swept back pectoral fins. Double-lobed snout and indented forehead. Long, slender tail. Brown above, white below. The stinger is located at base of the tail rather than half way or more down the tail as in the whiptail rays
Width up to 1.5 m (5 ft), weight up to 45 kg (100 lbs).

DISTRIBUTION/HABITAT: Tropical, Indo-West Pacific from South Africa north to India and possibly Thailand, Indonesia and southern China. Also in Okinawa, Ryukyu Islands.  The Javanese Cownose Ray inhabits tropical bays, estuaries, among mangroves, and near coral reefs over sand and mud bottoms. It can also tolerate brackish water.

DIET IN THE WILD: Feeds on clams, oysters and crustaceans. The ray sucks in sand and expels it out of its gills, blowing off sand covering its prey. (Looking for prey below)

REPRODUCTION: Mating pair orient in a venter to venter position, and the male inserts one or both claspers. Ovoviviparous, 1–2 pups per litter. Females have been known to leap out of the water and slam into the surface; this action seems to be an aid in birthing.

CONSERVATION STATUS: IUCN Red List  Vulnerable

A declining population is inferred from the unregulated nature of inshore fisheries as well as small litter size.

REMARKS:  Like its pelagic relatives the manta and devil rays, it swims by flapping its pectoral fins like wings, enabling it to swim at greater speeds than most bottom dwelling stingrays. Sometimes these “wings” protrude above the water, bearing a frightening resemblance to a shark.

References

California Academy of Sciences Reef Lagoon 2016

ARKive www.arkive.org/javanese-cownose-ray/rhinoptera-javanica/

fishbase www.fishbase.org/summary/SpeciesSummary.php?id=7971

IUCN Red List www.iucnredlist.org/details/60129/0

Ron’s WordPress Shortlink  http://wp.me/p1DZ4b-RK

Ron’s flickr http://www.flickr.com/photos/cas_docents/sets/72157608440813109/with/2981790284/