A very large and strikingly white sponge (possibly of genus Ianthella) that was kind of a landmark deep on the seaward drop-off in front of a pass in Madang's barrier reef. (Milinat Pass, Madang)
A barrel sponge positioned just in front of a pass in the barrier reef, allowing it to pick up maximum water flow from the currents that routinely rip through the reef passage. (Milinat Pass, Madang)
A huge barrel sponge (I'm 1.96 m tall and it's about my height) perches on the brink of a steep-sided bommie — the Moorish idol (Zanclus cornutus) at its base gives some idea of scale. (South Ema Reef, Kimbe Bay)
Another massive barrel sponge (Xestospongia sp.? — sponges are hard to identify visually!) of about the same height, visually dominating the reefscape around it. (South Ema Reef, Kimbe Bay)