(Platax pinnatus)Young batfish are known to look like things in their environment to avoid being detected by predators. For example, juvenile orbiculate (Platax orbicularis) and tiera batfish (P. tiera) mimic leafs floating near the ocean's surface. Juveniles are often found drifting along with floating clumps of algae (e.g., Sargassum) and miscellaneous debris, sometimes a long way from coastal habitats (it may be an effective way for them to emigrate from one reef to another). But the young pinnate batfish (Platax pinnatus), which is usually found close to the reef, engages in a different kind of mimicry. It resembles a polyclad flatworm in shape, in color, and locomotion (they both move by undulated the edges of the "body"). Most predators avoid ingesting these flatworms because they taste bad, so it is advantageous for the young batfish to look like the worm (this is an example of Batesian mimicry). When it comes to their diet, relatively little is known about what pinnate batfish eat. In some areas, they feed heavily on algae and are even thought to help prevent large algae species (known as macroalgae) from overgrowing part of the reef and killing the coral. But they also known invertebrate-eaters, including sponges and tunicates, soft corals and hydroids on their menu. While juvenile pinnate batfish are solitary creatures, as they grow, they sometimes form small shoals that roam the reef and feed together.
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