乐生活Recently, a specimen was received by exchanging collections with friends. It is difficult to see from the unique tooth structure of the specimen that it is the jaw of the round plow ray/Rhina ancylostoma. According to friends, the jaw was obtained from fishermen in Sri Lanka several years ago. Because of the long time and the rough way the fishermen deal with it, it is easy to see that it is the jaw of the round plow ray/Rhina ancylostoma. So the integrity of this specimen is slightly unsatisfactory, but because of the relatively rare specimens on the market, I have made a slight repair to this specimen. The repair method is rather rough, but I did try my best and the effect of the repair is passable.
As a large plough ray, the ultimate size of the round plough ray can reach 2.7m/135Kg. This species is endemic to the Indian Ocean and the Western Pacific Ocean, and is also the only existing species of the genus Raja. Round plough rays generally inhabit shallow water at depths of 3-90 m, feeding mainly on small bony fishes, crustaceans, bivalves and cephalopods. Their special dentate structure can help them crush the hard shell of their prey. Because their jaws are wavy and their heads are obtuse and round, they are similar to limulus. They are also called "Tachyphus undulatus" in Taiwan. The official English name is "Bowmouth guitarfish" and its common name is "Shark ray" because it resembles sharks in size (Sawrays and Spiked Ploughshares are similar in size), but the Ploughshares belong to the Rajanidae, not to the Rajaniformes belonging to various skates and mantas.
Round plough ray is relatively rare in Chinese waters, but its catch is large in the Indian Ocean, mainly bottom trawl and catch products. The fins of this species and all kinds of pointed plough ray can be made into high-grade shark fins, which is more expensive than shark fins. Owing to its gentle nature and easy breeding, round plow rays are also widely purchased in large aquariums for display, and these round plow rays usually come from wild catches. Likewise, habitat destruction is a major threat to this species. This specimen is a relic of history, which confirms the flourishing history of Ploughshare ray. At present, Ploughshare ray still appears in the local catch in Sri Lanka, Southeast Asia and South Asia, but its number is declining. At present, IUCN assesses its population as VU, and its future is not optimistic.
P1-3 Round Plough Rajaw Face-up, Top-View and Back-View (22.6 cm wide and 9.3 cm high after restoration, lack of relevant information such as specimen length, sex, collection time and location)
P4 The Relevant Description of the Round Plough Rays of the World
P5th Sunshine Ocean Park Raises and Exhibits the Adult Raja Round Plough
P6 Round Plough Ray Valuated for Sale at Fish Market in Southeast Asia (Image Source See Watermark)
P7 Twitter specimens were collected from fishermen in India by a specimen maker. It used to be so common that it could be found in the hands of local fishermen. But in recent years, the number of round plow rays has been declining (pictured from Simon De Marchi).
A spiny close-up of the back of P8 Round Ploughshare Ray, cut and dried in Southeast Asia to make jewelry (pictured from Wechat)
P9 Round Plough Ray Eco-Photo (Image from Arkive)
