Image of Mopalia Gray 1847

Description:

This venerable old chiton, just over 8 cm long, was also found at Sares Head. The head is to the right. The plates are so worn that the pattern can hardly be seen. The mantle color is unusual for this species but the mantle hairs are stiff and strap-like and both the Kozloff key and Aaron Baldwin's key identify it as Mopalia muscosa. The mantle and plates of this individual are also a whole city of symbionts, from several species of polychaete worms, small copepods, a tiny limpet (visible above at the top of plate 2), unidentified stalked invertebrates, and even a chironomid (midge fly) larva! I know that insects are rarely found in the ocean but the midge larva was clearly at home--crawling among other invertebrates and across the plates, nestling down in the edge of the mantle at the margin of the plates, etc., even though the chiton was fully immersed in seawater.