Living Camouflage | Phyllodesmium serratum Nudibranch

Living Camouflage | Phyllodesmium serratum Nudibranch

Confidence Level: 9.5/10
Family: Facelinidae (Aeolid Nudibranch)
Subfamily: Favorininae

⸻

???? Unique Features:
• Cerata look like tiny curled fingers of soft coral, translucent white with pale yellowish tips
• The body is slender, smooth, and semi-transparent, blending perfectly with its coral surroundings
• Cerata are blunt-ended and thick, arranged in graceful spirals that resemble bundled seaweed or xenia tentacles
• When still, it looks like a tuft of soft coral no larger than a paperclip

⸻

???? Size and Scale:
• Roughly 2–3 cm long, about the size of a grape or a shrimp’s tail segment
• Nestled among real soft coral, it’s so well-camouflaged you could stare right at it and think it’s part of the reef
• You’d easily miss it without a macro lens — a reminder that some of the reef’s wildest creatures are no bigger than your fingernail

⸻

???? Biological Notes:
• Feeds on soft corals, especially from the xeniid and alcyoniid families
• Unlike many aeolid nudibranchs, it doesn’t use stinging cells for defense, instead relying entirely on camouflage
• Some Phyllodesmium species host symbiotic algae (zooxanthellae), though P. serratum is not among them

⸻

???? Habitat:
• Found across the Indo-Pacific — the reefs of Siquijor, Philippines are prime real estate
• Lives among soft coral gardens at 5–30 meters deep
• Often motionless during the day, resembling the very coral it feeds on

⸻

???? Rarity Level:

7.5/10 — Not extremely rare, but incredibly difficult to spot. Think of it as reef hide-and-seek on expert mode.