Crypsis

Figure 1: Spider conch being almost completely cryptic in its natural habitat.

The shells of spider conchs are often densely covered with brown and green algae (See Figure 1). This gives them the appearance of a boulder or an old coral fragment, which allows them to blend in with their surroundings in reef flat zones.

The body colouration of spider conchs also allows them to blend in with their surroundings (See Figure 2). The foot, mantle and eye-stalks are patterned in such a way that they closely resemble a sandy substrate.

Figure 2: Body colouration of spider conch.