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Not just a huge collection of Shark Pictures: Elasmodiver.com contains images of sharks, skates, rays, and a few chimaera's from around the world. Elasmodiver began as a simple web based shark field guide to help divers find the best places to encounter the different species of sharks and rays that live in shallow water but it has slowly evolved into a much larger project containing information on all aspects of shark diving and shark photography.

There are now more than 10,000 shark pictures  and sections on shark evolution, biology, and conservation. There is a large library of reviewed shark books, a constantly updated shark taxonomy page, a monster list of shark links, and deeper in the site there are numerous articles and stories about shark encounters. Elasmodiver is now so difficult to check for updates, that new information and pictures are listed on an Elasmodiver Updates Page that can be accessed here:

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Red Stingray

 

 

View all available Red Stingray Images in the Shark Picture Database

 

Common Names: Red stingray, whip stingray.

 

Scientific Name: Hemitrygon akejai.

 

Synonyms: Dasyatis akejei, Trygon akejei. Some scientists consider D.multispinosa to be a synonym also.

 

Family: Dasyatidae.

 

Identification: The red stingray has a rhomboid disc with a triangular and slightly produced snout, straight anterior margins, rounded free tips and convex posterior margins. The dorsal surface of the body disc is uniformly reddish brown sometimes lighter at the disc margin and around the eyes, spiracles and laterally on the tail. Mature adults have tubercles on back and tail. Ventral surface of disc white with yellow/orange or dark margin.

Dorsal keel and ventral finfold present on tail. Tail around 1.5 x length of body. Upper surface of tail has 1-3 stinging spines. Filamental rear section of tail dark or black.

 

 

Size: Maximum length with tail intact 200cm but more commonly 100cm.

 

Habitat: Found mostly on sand (sometimes adjacent to reefs) in shallow coastal flats and bays below 10m. Also on mud and in estuarine environments.

 

Distribution: Restricted to the northwest Pacific. Common from Okinawa to Hokkaido in Japan. Also recorded from Korea, mainland China and Taiwan. Records from Thailand, the Philippines, Fiji and Tuvalu may be erroneous identifications. The range of the red stingray is currently under review.

 

Diet: Crustaceans, small bony fishes, annelid worms and occasionally mollusks.

Reproduction: Ovoviviparous. In the somewhat antiquated 'Reef Sharks and Rays of the World' Scott Michael lists the red stingray as having up to 10 pups per litter. According to more recent observations by H. Ishihara, the red stingray has a very low fecundity and gives birth to only one pup per litter.

 

Conservation Status: According to the IUCN, the red stingray is subject to high fishing effort and is caught in commercial quantities in the coastal waters of Japan and even in brackish waters. It is taken as bycatch in the bottom trawl fishery, gillnet, set net and hook and line fishery targeting demersal bottom fishes such as flounders. This bycatch is utilized and landings are reported to be declining. Fecundity is very low with one pup per litter reported. Due to the current high level of bycatch and strong fishing pressure in its area of occurrence, which will have depleted the population, this species should be classified as Near Threatened. Data need to be collected in order to accurately assess the population status, which may show that the species falls into a higher threat category.

 

Photographs: Ito, Chiba Prefecture, Japan.

Similar species: There are two other species of stingrays caught around Honshu Island in the Sea of Japan that could be confused with the red stingray. The pitted stingray Dasyatis matsubarai has a dark gray dorsum with a line of white spots on each pectoral fin. The Izu stingray Dasyatis izuensis has a distinctively white caudal finfold.

Further afield, the red stingray could be confused with the Pink or Tahitian stingray Dasyatis fai which has a much longer caudal filament (tail whip) and a uniformly pale ventrum.

 

Reaction to divers: Probably skittish in a normal encounter but very easy to approach in a baited situation - see below.

 

Diving Logistics: The best place to encounter red stingrays is in Ito, Japan where they are inadvertently baited in as part of a shark feed designed to attract banded hound sharks. For more information on this feed, contact Bigfishexpeditions.com

 

References and Citations:

  • Huveneers, C. & Ishihara, H. 2006. Dasyatis akajei. The IUCN Red List of Threatened Species. Version 2015.1. <www.iucnredlist.org>.

 

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