As we culminate the Month of the Ocean this May 2022, the National Museum of the Philippines features the Bohol Nudibranch (Discodoris boholiensis) locally called Hilahila.
The Hilahila (Bohol Nudibranch) belongs to the large sea slug family of Discodoridae named after Bohol island where the species was discovered and identified. They occur in the rubbles and sandy areas of the coral reef in tropical waters.
The term Nudibranch is derived from the Greek word “nudus” and brankhia” which means “naked gills” because they are flat, shell-less mollusks having exposed flower-like gills. They are identified with their jelly-like oblong shape body (6-10 cm) with small brown-tipped bumps on their back and with oral, foot, and eye tentacles. They have 2 sensitive tentacles on the head called rhinophores which they use to detect prey and predators. These species are considered the “Gem of the Sea” for their majestic colors and striking graceful appearances underwater.
During the daytime, the hilahila remain hidden in crevices and spend their nighttime moving through the sands and corals feeding mainly on sponges. They elude their predators through secretions of toxins in their skins derived from the food they eat. Their vibrant colors also protect them from their predators as they camouflage and blend into their environment. As hermaphrodites, they mate with any member of their species. They then lay eggs in a spiral-shaped or coiled form in sands and corals which hatch in 11-12 days.
The Nudibranchs are short-lived and can only live for almost a year. According to Endangered Species International, most species are becoming rare and must be protected. Let’s all do our part in protecting and conserving these beautiful reef cleaners for the sustainability of our marine environment.
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