Northern river shark
Glyphis garricki
Glyphis garricki is a relatively large species of river shark ( Glyphis ) within the requiem sharks ( Carcharhinidae ). The shark is found in brackish water areas and in the adjacent sea on the coast of Australia's Northern Territory. Even with river sharks in the Fly River in southwestern Papua New Guinea, it could be either this way.
Features
Glyphis garricki is 1.45 ( males ) and 2.50 (females ) feet long. He has a stocky body that is white on the upper side gray, underside and otherwise has no other color markings. The fin edges are dark or black. The head is flattened, the short rostrum is broadly rounded from above or below line of sight, the eyes are small, the injection holes are missing. In the upper jaw the teeth are broad and triangular with serrated edges, the lower jaw is narrower with a slender tip. The first dorsal fin is above the posterior third of the pectoral fins, the second dorsal fin reaches two thirds of the height of the first. A Interdorsalkamm missing. The anal fin has a very deep indentation at its rear edge.
In the area of distribution of Glyphis garricki also the bull shark ( Carcharhinus leucas ) occurs. Glyphis garricki can be distinguished from it by its larger second dorsal fin and through the small eyes that are still in the gray colored head region, while the eyes of the Bull Shark are right on the boundary line between gray top and whitish underside. In addition Glyphis garricki is steel gray, in contrast to Gray the Bull Shark.
Endangering
Glyphis garricki is in the Red List of IUCN threatened with extinction as ( " Critically Endangered " ) classified. Overall, there will be only 250 mature specimens and no subpopulation contains more than 50 individuals.