Javanese Cownose Ray

This species is sometimes found in extremely large groups, with schools of up to 500 rays having been reported (2) (3). Feeding on a diet of clams, oysters and crustaceans (2), the ray uses its large plate-like teeth to crush the shells of its prey (3). Reproduction is ovoviviparous, with live young being 'born' after they have hatched inside the female (2).

There are currently no conservation measures targeting this species.

Cownose rays (Rhinoptera) have earned their common name for their unusual-looking heads, which feature a double-lobed snout and indented forehead (2). As with most rays, the body is flattened, with the pectoral fins broadly expanded and fused with the head and trunk to form a disc (3). This smooth-skinned species is characterised by a kite-shaped body-disc, which is brown on the upper surface and white below (2) (3). The long, thin, whip-like tails of cownose rays (Rhinoptera) are distinctly demarcated from the body and armed with one or more stings.

A benthic species found over sand and mud bottoms of inshore coastal waters, in bays, estuaries and near coral reefs (2) (3).

Ranging across the Indo-West Pacific, from Durban, South Africa, north possibly to India, Thailand, Indonesia, and southern China. Also in Okinawa, Ryukyu Island and possibly Australia (2).

Classified as Vulnerable (VU) on the IUCN Red List (1).

Cownose rays (Rhinoptera) are fished for food, but not generally taken in large numbers. Of only minor importance to fisheries, they are still caught incidentally in hook-and-line and trawling operations (3). However, the true impact fisheries are having on Javanese cownose ray populations is unknown.

Found in bays, estuaries, and near coral reefs (Ref. 12951), over sand and mud bottoms (Ref. 9710). Large schools with up to 500 individuals have been reported (Ref. 12951). Feeds on clams, oysters and crustaceans. Also in Ref. 9137.

Males court by nipping the female's dorsum. Mating pair orient in a venter to venter position, and the male inserts one or both claspers. The pair usually rests on the substrate, with the female on top of the male. Mating lasts about 30 seconds (Ref. 12951) to 1 minute (Ref. 49562). Exhibit ovoviparity (aplacental viviparity), with embryos feeding initially on yolk, then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus, fat or protein through specialised structures (Ref. 50449). Size at birth ~60 cm WD. One large pregnant female (~130 cm WD) contained a single late-term embryo 61 cm WD (Ref.58048).

Double-lobed snout and indented forehead; jaws usually with 7 rows of plate-like teeth; no caudal fin (Ref. 5578). Brown above, white below (Ref. 5578).

Found in bays, estuaries, and near coral reefs (Ref. 12951), over sand and mud bottoms (Ref. 9710). Usually solitary or in small aggregations (Ref. 114953). However, large schools with up to 500 individuals have been reported (Ref. 12951). Feeds on clams, oysters and crustaceans (Ref. 12951). Lives to over 2 years in captivity (Ref. 12951). Ovoviviparous (Ref. 50449). Edible (Ref. 30573). Caught mainly by gill net fisheries (Ref. 114953), occasionally by bottom trawl, demersal inshore gillnet and tangle net fisheries. Utilized for its meat (Ref. 58048).

fisheries: commercial; gamefish: yes

分布於熱帶及溫帶各沿海地區。

罕見大型魚種，通常由近海底層延繩釣捕獲，具食用價值。

身體扁平，後緣尖銳。頭厚重。嘴大且寬廣，牙齒平板，通常上下顎為7排牙齒。下唇具許多乳頭突起物覆蓋物。鼻瓣邊緣具有流蘇狀構造，下與嘴部重疊。體盤呈鐮刀形或菱形，體盤寬為體盤長之1.5倍。體盤與出水孔位於側面，背鰭呈三角形，小且直立，腹鰭位於體盤基部，尾巴長如鞭形，背鰭後有鋸齒狀的棘刺。背部及腹部體盤表面(包含頭和尾)具有一些細刺。體盤背面呈深灰咖啡色到咖啡色，下面灰白，尾部咖啡色。(陳柔蓉、林沛立2012/11編寫)

常大群出現於海中上層，但多半棲於底中水層，卵胎生，食底棲軟體動物、甲殼動物和魚類。

The flapnose ray or Javanese cownose ray (Rhinoptera javanica) is a species of fish in the family Rhinopteridae. It is found in the Indo-Pacific off China, India, Indonesia, Iran, Japan, Madagascar, Malaysia, Mozambique, Pakistan, the Philippines, Seychelles, Somalia, South Africa, Sri Lanka, Taiwan, Tanzania, Thailand, Vietnam and possibly Australia. Its natural habitats are open seas, shallow seas, subtidal aquatic beds, coral reefs, estuarine waters, and coastal saline lagoons.

Found above sand and mud bottoms of inshore reefs, sometimes in large aggregations (Ref. 9710).