|
|
|
|
|
River SharkThe river shark is one of 6 rare species of the genus Glyphis. The river sharks are members of the family Carcharhinidae, and thus share the basic characteristics of the group. Features of Glyphis spp. General characteristics In general, all river sharks feature the following field characteristics: - a short, broadly rounded snout (its length less than the mouth width)
- small, wide-spaced nostrils
- broad, serrated upper teeth
- very short labial furrows (lip grooves), restricted to the jaw corners
- an anal fin with a deeply excised posterior margin
Morphology River sharks are very similar in overall morphology to whaler sharks of the genus Carcharhinus, but can be distinguished from them by the following characteristics: Cusps of lower teeth protrude prominently when mouth is closed Second dorsal fin is 1/2 to 3/5 the height of the first dorsal fin Origin of second dorsal fin slightly anterior to origin of anal fin Precaudal pit is longitudinal rather than crescent-shaped Species Six species of river sharks are known, although due to their secretive habits, other species could easily be lying undiscovered. Asia Ganges Shark Glyphis gangeticus (Mller & Henle, 1839) Definitely known from the Hooghly-Ganges river system, West Bengal, India, and likely from the vicinity of Karachi, Pakistan. Oceania Speartooth Shark Glyphis glyphis (Mller & Henle, 1839) Uncertain. Speartooth-like sharks occur in Borneo, New Guinea, and Queensland, Australia, but it is uncertain at present if any of these are the true G. glyphis. The holotype has no capture locality listed for it. Irrawaddy River Shark Glyphis siamensis (Steindachner, 1896) The only known specimen is from the Irrawaddy River, near Rangoon. Until very recently, this species was regarded as an aberrant specimen and possible synonym of (the same species as) the Bull Shark, but shark systematist Leonard J.V. Compagno now considers it a member of the genus Glyphis, distinct from the other known species. Glyphis species A yet described Known from two specimens from estuarine waters of the lower reaches of the Bizant River in Queensland, Australia, where it occurs along with the Bull Shark. It is also known from the Alligator River system of the Northern Territory, where it occurs with Glyphis species C. Intriguingly, Glyphis specimens from the Adelaide River, Northern Territory, that have provisionally been identified as this species display very different vertebral counts (148 total vertebrae, versus 217 in specimens from the Bizant River). Glyphis species B yet described Known from a single specimen from Borneo. Recently, several small Glyphis have been collected from the Kinabatangan River of Sabah, in northern Borneo. These may be the same species as Glyphis species B. The species is presently in the process of being described by Sarah Fowler and Leonard J.V. Compagno. Glyphis species C yet described Only nine specimens have ever been collected - an immature female taken about 100 km up the Adelaide River in 1989, an adult male taken some 60 km up the South Alligator River in 1996, and in 1999, five females and two males from the East, West and South Alligator Rivers, in brackish water, with salinity ranging from 6 to 26 ppt. This species also occurs alongside Glyphis species A.
|  | katsuura, chiba
ichihara, chiba
nagareyama, chiba
yachiyo, chiba
abiko, chiba
kamogawa, chiba
kamagaya, chiba
kimitsu, chiba
futtsu, chiba
urayasu, chiba
yotsukaido, chiba
| sodegaura, chiba
yachimata, chiba
inzai, chiba
shiroi, chiba
tomisato, chiba
sherwood park, alberta
joseph cook
jimmy driftwood
hal prince
khaldis
star party
| freshwater shark
penetanguishene, ontario
hanno the navigator
steroid hormone
dallas fort worth metroplex
midland, ontario
hiratsuka, kanagawa
fujisawa, kanagawa
odawara, kanagawa
neville bonner
niigata, niigata
| nagaoka, niigata
ansari x prize
canadian space agency
sanjo, niigata
kashiwazaki, niigata
shibata, niigata
niitsu, niigata
ojiya, niigata
kamo, niigata
tokamachi, niigata
mitsuke, niigata
|
|
|
| |
|
|