There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
05-29-2018, 04:41 AM( This post was last modified: 05-29-2018, 04:48 AM by epaiva )
Here we have a short HD video showing the jaw motions of the elongate tigerfish (Hydrocynus forskahlii). This specimen was collected from Lake Nasser, Egypt in January 2011. Current research in my lab at American University in Cairo is investigating the functional morphology of the elongate tigerfish's bite mechanics. Tigerfishes are endemic to Africa's rivers and lakes. They are also members of the Order Characiformes and as such are related to the piranhas, pacus, and vampirefishes of South America. What's notable about tigerfishes is that unlike their south american relatives that have immobile upper jaws, the tigerfish upper jaw goes through a substantial dorsal rotation (approx. 30 degrees). This rotation in combination with extensive lower jaw depression gives the tigerfish a large gape that also acts to point their razor sharp teeth in a forward orientation which presumably helps them to impale their prey during a rapid ram strike. Also, note how as the jaw closes the teeth interdigitate into semi-enclosed sockets on the opposing jaw. This interlocking beartrap-like bite enables them to chomp small fish prey into pieces and even cut chunks of flesh out of larger prey. If you want to learn more, this species is highlighted in the National Geographic Channel's Hooked: Lake Monsters (in the U.S.) & Hooked: Nile Giant (Internationally).
