Java stingaree
Encyclopedia
The Java stingaree is a species
of stingray
in the family
Urolophidae, known only from a single female specimen 33 cm (13 in) long caught off Jakarta
, Indonesia
. This species is characterized by an oval-shaped pectoral fin disc longer than wide, and a tail with a dorsal fin
in front of the stinging spine and a caudal fin. It is brown above, with darker and lighter spots. The International Union for Conservation of Nature has listed the Java stingaree as Critically Endangered
; it has not been recorded since its discovery over 150 years ago, and its range is subject to heavy fishing pressure and habitat degradation.
purchased the sole known specimen of the Java stingaree at a fish market in Jakarta. He described it as Trygonoptera javanica in an 1864 volume of the scientific journal
Monatsberichte der Akademie der Wissenschaft zu Berlin (Monthly Report of the Academy of Sciences, Berlin). Subsequent authors moved this species to the genus Urolophus.
, perhaps in the vicinity of Jakarta. Its exact range, and depth and habitat
preferences, are unknown but probably very restricted.
s. The nostrils are crescent-like, and between them is a curtain of skin with a minutely fringed posterior margin. The mouth is bow-shaped, and contains three papillae (nipple-like structures) on the floor. The teeth are closely arranged with a quincunx
pattern; each is small with a transverse ridge on the crown. The five pairs of gill slit
s are short.The pelvic fins are almost square, with rounded corners. The tail is shorter than the disc and bears a prominent dorsal fin
about halfway along its length; immediately posterior to the dorsal fin is a serrated stinging spine. The tail ends in a leaf-shaped caudal fin, whose dorsal origin lies behind the ventral origin. The skin is devoid of dermal denticles, though there are tiny white bumps on the upper central portion of the disc. This species is dark brown above, with many indistinct darker and lighter spots, and pale below. The sole specimen measures 33 cm (13 in) long.
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of stingray
Myliobatiformes
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown that the myliobatiforms are a monophyletic group, and that its more derived members evolved their...
in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Urolophidae, known only from a single female specimen 33 cm (13 in) long caught off Jakarta
Jakarta
Jakarta is the capital and largest city of Indonesia. Officially known as the Special Capital Territory of Jakarta, it is located on the northwest coast of Java, has an area of , and a population of 9,580,000. Jakarta is the country's economic, cultural and political centre...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. This species is characterized by an oval-shaped pectoral fin disc longer than wide, and a tail with a dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
in front of the stinging spine and a caudal fin. It is brown above, with darker and lighter spots. The International Union for Conservation of Nature has listed the Java stingaree as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
; it has not been recorded since its discovery over 150 years ago, and its range is subject to heavy fishing pressure and habitat degradation.
Taxonomy
In July of 1862, German zoologist Eduard von MartensEduard von Martens
Eduard von Martens sometimes known as Carl or Karl Eduard von Martens, was a German zoologist.Born in Stuttgart in 1831, von Martens attended universities in Tübingen, Stuttgart and Munich, graduating from the University of Tübingen in 1855. In 1860, he set off as part of an expedition to the Far...
purchased the sole known specimen of the Java stingaree at a fish market in Jakarta. He described it as Trygonoptera javanica in an 1864 volume of the scientific journal
Scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of scientific journals in publication, and many more have been published at various points in the past...
Monatsberichte der Akademie der Wissenschaft zu Berlin (Monthly Report of the Academy of Sciences, Berlin). Subsequent authors moved this species to the genus Urolophus.
Distribution and habitat
The Java stingaree has only been found off JavaJava
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
, perhaps in the vicinity of Jakarta. Its exact range, and depth and habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
preferences, are unknown but probably very restricted.
Description
The Java stingaree has an oval pectoral fin disc slightly longer than wide; the leading margins are gently convex and converge at a blunt angle on the snout. The eyes are followed by larger, comma-shaped spiracleSpiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
s. The nostrils are crescent-like, and between them is a curtain of skin with a minutely fringed posterior margin. The mouth is bow-shaped, and contains three papillae (nipple-like structures) on the floor. The teeth are closely arranged with a quincunx
Quincunx
A quincunx is a geometric pattern consisting of five points arranged in a cross, that is five coplanar points, four of them forming a square or rectangle and a fifth at its center...
pattern; each is small with a transverse ridge on the crown. The five pairs of gill slit
Gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of Cartilaginous fish such as sharks, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...
s are short.The pelvic fins are almost square, with rounded corners. The tail is shorter than the disc and bears a prominent dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
about halfway along its length; immediately posterior to the dorsal fin is a serrated stinging spine. The tail ends in a leaf-shaped caudal fin, whose dorsal origin lies behind the ventral origin. The skin is devoid of dermal denticles, though there are tiny white bumps on the upper central portion of the disc. This species is dark brown above, with many indistinct darker and lighter spots, and pale below. The sole specimen measures 33 cm (13 in) long.
Biology and ecology
Very little is known of the natural history of the Java stingaree. It is presumably aplacental viviparous with a small litter size, as in other stingarees.Human interactions
No new Java stingaree specimens have emerged since the first was discovered over 150 years ago, and it is feared to be extinct. There is heavy fishing activity within its range, as well as habitat degradation from the proximity of major population centers. While it is possible that captured specimens have gone unrecognized, if this species still survives its population would almost certainly be gravely imperiled, leading the International Union for Conservation of Nature (IUCN) to assess it as Critically EndangeredCritically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
.