NPCs composing that spawngroup :

a_twitching_swordfish (100%)

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

sirens_81, range=55 (-201,102,3)

a_coldspine_sea_hors_190199, range=85 (-152,20,-22)

a_coldspine_seahorse (100%)

sirens_223843_takp_import_v0, range=92 (-237,91,3)

an_enthralled_molkor (50%)
an_enthralled_ulthork (50%)

sirens_223858_takp_import_v0, range=54 (-200,102,3)

a_servant_sea_elephant (50%)
a_servant_walrus (50%)

sirens_an_enthralled_ulthork16_takp_import_v0, range=69 (-84,74,3)

an_enthralled_ulthork (100%)