Possible Clues:

• Ruthless type
• Orinoco biter
• Rap Ian plays round hospital – it's vicious
• A rapacious creature, I managed hospital area under parking
• Country under Portugal has endless fish!
• Vicious fish
• South American predator whose name translates to 'tooth fish'
• Swimmers in unusual number competed, having bit of a laugh
• Fish known for its bite
• Fish with razor-sharp teeth