Bluehead Wrasse, Thalassoma amblycephalum
A Bluehead Wrasse at a depth of 13 m, North Solitary Island, New South Wales, 19 May 1997. Image: Ian Shaw
© Ian Shaw

It appears that a range of species from a number of different families eat sponges.  These include some species of angelfishes (Pomacanthidae), wrasses (Labridae), leatherjackets (Monacanthidae), boxfishes (Ostraciidae) and pufferfishes (Tetraodontidae) For some species, sponges comprise over 70% of the diet. The references below provide additional details.

References:

  1. Randall, J.E. & W.D. Hartman. 1968. Sponge-feeding fishes of the West Indies. Mar Biol 1:216–225.
  2. Ruzicka, R. & D.F. Gleason. 2008. Latitudinal variation in spongivorous fishes and the effectiveness of sponge chemical defenses. Oecologia. 154:785–794.