Banana Nudibranch

Overview

The Banana Nudibranch (Notodoris minor) is a large, striking dorid nudibranch known for its bright yellow body and network of black lines. It is a specialized predator that relies on specific calcareous sponges for both its diet and camouflage, often blending seamlessly into its surroundings.

Distribution & habitat

This species is widely distributed across the Indo-West Pacific, ranging from East Africa, the Red Sea, and the Mascarene Islands to the Philippines, Indonesia, Japan, and the Great Barrier Reef. It is typically found on coral reef substrates where its preferred food sponges are present.

Appearance

Reaching up to 14 cm in length, this nudibranch has a tough, leathery skin covered in small pustules and spicules. Its body is bright yellow with a network of irregular, diagonal, and transverse black lines. The feathery gills are located mid-dorsum and are partially concealed by three large, warty lobes that mimic the appearance of sponge growths. While adults generally have yellow rhinophores, juveniles often display distinct black tips.

Feeding

Notodoris minor feeds exclusively on calcareous sponges in the family Leucettidae, such as Pericharax heterorhaphis and Leucetta primigenia. Observers often find the nudibranch near piles of clean, discarded sponge spicules, suggesting it may digest the sponge tissue while leaving the skeletal framework behind.

Biology & behavior

This species is notably slow-moving, a trait that may help it maintain its camouflage as a sponge-like object. Its bright coloration serves as an aposematic signal to warn potential predators of its toxicity. Reproduction involves laying yellow egg masses near its food source, which hatch into free-swimming veliger larvae that drift with ocean currents before settling.