A Master of Invisibility
Melibe engeli (Risbec, 1937) is one of the most extraordinary nudibranchs at our macro dive sites in Romblon, Philippines. Its body is almost entirely transparent. This makes it one of the most cryptic nudibranchs in the Indo-Pacific. In addition, brown zooxanthellae — photosynthetic algae — are visible as tiny speckles through the transparent body wall. Remarkably, Melibe engeli captures these algae from the water column during feeding, rather than from its prey. As a result, it gains additional energy from sunlight. It belongs to the order Nudibranchia, suborder Dendronotina, family Tethydidae. You can find it on iNaturalist.
How It Hunts
Like all Melibe species, Melibe engeli is an active predator. It uses a large, expandable oral hood to catch small crustaceans and copepods. The hood opens wide, then contracts rapidly when prey is detected. Notably, this species has no radula at all — it swallows prey whole. It is closely related to Melibe colemani, also documented in our Marine Life Encyclopedia. Both species share the same family and the same hunting strategy. Originally described from New Caledonia, Gosliner and Smith first documented it in the Philippines in 2003 — confirming Romblon as part of its range.
Finding It at Sunset Cove
At Sunset Cove Beach & Dive Resort, Melibe engeli is one of the rarest finds possible. Its transparency makes it almost invisible against sandy rubble. Therefore, finding it requires a slow search and a trained eye. Night dives offer the best chance — the oral hood is often extended during active feeding. For underwater macro photographers in Romblon, a shot of this species against a dark background reveals its ghostly transparent body. Consequently, it is one of the most prized images from our dive sites.