scubaseason

Nudibranch spp.

Chromodoris / Hypselodoris spp.

Sighting evidence at Hilutungan Channel, Mactan Island

Hilutungan Channel hosts a diverse nudibranch assemblage — Chromodoris, Hypselodoris, and Phyllidiella species are found on virtually every dive, with electric-blue, orange, and spotted specimens visible on coral rubble and sponge surfaces from 8 m down. Nudibranchs are key indicator species for reef health and chemical diversity — their bright aposematic colours advertise toxins sequestered from sponge prey. The channel's sanctuary-protected rubble zones and sponge gardens support one of the highest nudibranch species densities on Mactan Island.

Evidence at this site

No confirmed records on file at this site

Nudibranch spp. is listed as a curated species here based on historical reports.

How is this calculated?

Sighting evidence is compiled from iNaturalist observation records within a set proximity radius, filtered for quality-grade observations. “Last confirmed” is the date of the most recent research-grade record. Record count covers a rolling 24-month window. Confidence reflects record count, recency, and consistency of seasonal signal.