Kai stingaree
Encyclopedia
The Kai stingaree is a species
of stingray
in the family
Urolophidae, known only from two juveniles collected from 236 m (774.3 ft) deep in the Kai Islands
of eastern Indonesia
. This species has a rhomboid
pectoral fin with a very blunt, rounded snout, and a tail with lateral skin folds, a leaf-shaped caudal fin, and no dorsal fin
. It is brown above with blackish coloring on the upper surface of each eyeball. The larger of the two specimens measures 23 cm (9.1 in) long. The International Union for Conservation of Nature (IUCN) does not yet have enough information to assess the Kai stingaree beyond Data Deficient
. It presently faces little fishing, though this is liable to change in the future.
collected a number of hitherto-unknown fishes from Station 192 in the Kai Islands, including two specimens of the Kai stingaree. British zoologist Albert Günther wrote a brief description of the new species and published it in 1880, as part of the scientific reports the followed the Challenger expedition
.
in the Kai Islands, at a depth of 236 m (774.3 ft). Given that no further specimens have emerged since the originals, it seems to be extremely rare and/or have a highly restricted range.
s. Between the nostrils is a skirt-shaped curtain of skin, whose posterior corners are extended into small lobes. The teeth are small, with roughly oval bases. The five pairs of gill slit
s are short, and the pelvic fins are small with rounded margins. The tail is slightly shorter than the disc, bearing a skin fold running along either side and a leaf-shaped caudal fin at the end. A serrated stinging spine is placed on top, about halfway along the tail's length; there is no dorsal fin
. The skin is completely smooth. This species is a plain yellowish brown above, transitioning sharply to blackish on the upper surface of each eyeball. The two specimens are both juveniles, one measuring 22 cm (8.7 in) and the other 23 cm (9.1 in) in length.
. Indonesian trawl fisheries do not presently operate below a depth of 200 m (656.2 ft), though this is anticipated to change in the future, at which time this species may be threatened.
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 two juveniles collected from 236 m (774.3 ft) deep in the Kai Islands
Kai Islands
The Kai Islands of Indonesia are in the south-eastern part of the Maluku Islands, in Maluku Province.-Geography:...
of eastern 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 has a rhomboid
Rhomboid
Traditionally, in two-dimensional geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are oblique.A parallelogram with sides of equal length is a rhombus but not a rhomboid....
pectoral fin with a very blunt, rounded snout, and a tail with lateral skin folds, a leaf-shaped caudal fin, and no 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...
. It is brown above with blackish coloring on the upper surface of each eyeball. The larger of the two specimens measures 23 cm (9.1 in) long. The International Union for Conservation of Nature (IUCN) does not yet have enough information to assess the Kai stingaree beyond Data Deficient
Data Deficient
Data Deficient is a category applied by the IUCN, other agencies, and individuals to a species when the available information is not sufficient for a proper assessment of conservation status to be made...
. It presently faces little fishing, though this is liable to change in the future.
Taxonomy
From September 9 to 29, 1874, the research ship HMS ChallengerHMS Challenger (1858)
HMS Challenger was a steam-assisted Royal Navy Pearl-class corvette launched on 13 February 1858 at the Woolwich Dockyard. She was the flagship of the Australia Station between 1866 and 1870....
collected a number of hitherto-unknown fishes from Station 192 in the Kai Islands, including two specimens of the Kai stingaree. British zoologist Albert Günther wrote a brief description of the new species and published it in 1880, as part of the scientific reports the followed the Challenger expedition
Challenger expedition
The Challenger expedition of 1872–76 was a scientific exercise that made many discoveries to lay the foundation of oceanography. The expedition was named after the mother vessel, HMS Challenger....
.
Distribution and habitat
The two Kai stingaree specimens were collected over blue mudMud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
in the Kai Islands, at a depth of 236 m (774.3 ft). Given that no further specimens have emerged since the originals, it seems to be extremely rare and/or have a highly restricted range.
Description
The pectoral fin disc of the Kai stingaree is diamond-shaped and much wider than long, with narrowly rounded outer corners. The leading margins of the disc converge at an obtuse angle on the snout, which is rounded and non-protruding. The eyes are immediately followed by teardrop-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. Between the nostrils is a skirt-shaped curtain of skin, whose posterior corners are extended into small lobes. The teeth are small, with roughly oval bases. 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, and the pelvic fins are small with rounded margins. The tail is slightly shorter than the disc, bearing a skin fold running along either side and a leaf-shaped caudal fin at the end. A serrated stinging spine is placed on top, about halfway along the tail's length; there is no 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...
. The skin is completely smooth. This species is a plain yellowish brown above, transitioning sharply to blackish on the upper surface of each eyeball. The two specimens are both juveniles, one measuring 22 cm (8.7 in) and the other 23 cm (9.1 in) in length.
Biology and ecology
Virtually nothing is known of the natural history of the Kai stingaree. It is presumably aplacental viviparous with a small litter size, like other stingarees.Human interactions
The International Union for Conservation of Nature (IUCN) currently has insufficient data to assess the Kai stingaree beyond Data DeficientData Deficient
Data Deficient is a category applied by the IUCN, other agencies, and individuals to a species when the available information is not sufficient for a proper assessment of conservation status to be made...
. Indonesian trawl fisheries do not presently operate below a depth of 200 m (656.2 ft), though this is anticipated to change in the future, at which time this species may be threatened.