FIGURE 5 in The Sea Slug Phanerophthalmus luteus (Gastropoda: Opisthobranchia) and its Habitat and Ecology at the Marine Jellyfish Lake (Ongeim'l Tketau), Palau, Western Pacific Ocean

FIGURE 5. Hydrography of Jellyfish Lake. The water column is divided into an oxic and an anoxic zone by a bacterial plate that creates a chemo- and thermocline. The bacteria absorb all the light and digest most of the vegetation (except larger branches). No foraminifera or animals are known to live below the bacterial plate due to the absence of oxygen in the water column. Phanerophthalmus luteus is restricted to the upper 3 to 10 m in the oxygenated part of the water column; they are most abundant between 4.5 and 7.6 m. Figure modified from Venkateswaran et al. (1993) by adding the depth distribution of P. luteus.