I was surprised when I saw this small bladderclam (Mytilimeria nuttalli) covered in a compound tunicate with only the siphon exposed. Apparently this clam is often found encased within a compound tunicate colony. The bladderclam is a hermaphrodite, but spawns eggs and sperm at different times. The larvae settle onto compound tunicate (ascidian) colonies, and eventually become completely covered with just their inhalant and exhalant siphons showing. The bladderclam can grow to 1.8 inches (4.6 cm) across, and has a range from southern Alaska to northern Mexico.