NPCs composing that spawngroup :

a_reef_hammerhead_shark (50%)

a_reef_shark (50%)

NPCs spawning around that spawngroup :
(Max range : 100)

powater_a_triloun_water_guardian54, range=70 (-1026,-7,-29)

a_triloun_water_guardian (100%)

powater reef mobs, range=89 (-945,95,-31)

powater traps, range=78 (-972,83,-56)

a_swarm (10%)
a_swarm (10%)
HatchSpawnPH (90%)
HatchSpawnPH (90%)

powater Monstrous_Sea_Turtle, range=14 (-946,16,-59)

powater large mobs, range=56 (-947,62,-41)