Needler Mango

*Mango kestros*, the dart-throwing shark. Territorial predator capable of launching uranium-tipped tusks at up to twenty meters per second.

1. Erupted jaw

Dominated by six upper jaw tusk sockets. The lower jaw has receded into the throat for rasping and crushing. Muscles behind each tusk crank ligaments around hard anchors, storing mechanical energy like a crossbow.

2. Teeth battery

Tusks are reloaded from mature spares deeper in the skull. Needlers constantly form new tusks by 'sneezing' ground mineral paste and quick-setting enzyme into dental sacs. Each tusk is tipped with a self-sharpening uranium oxide cap.

3. Body structure

The equally spaced dorsal, pectoral and pelvic fins give the needler excellent stability and aim control. A large caudal fin drives the needler on the sprint. Like its relative the marrowbreach, it has no thruster. Four 'whiskers' detect water currents to help aim.

4. Behavior

Needlers are social, nesting and sometimes hunting in family groups. They may be pack predators — cooperating to bring down larger organisms. Their need for constant mineral intake makes them fiercely territorial.

5. Evolutionary history

The needler shares a close relationship with the nibbler mango, which has a similar battery of constantly regenerating teeth. The needler may have evolved its tusks to penetrate hard shells—first firing into prey already clamped in its jaw, then launching the tusks as harpoons.

Assessment: dangerous, territorial predator. Avoid or distract even when operating submersibles.