Sentry: The autonomous underwater vehicle, Sentry (yellow), is lowered into the Atlantic Ocean off the U.S. East Coast. Credit: Andrew Billings, WHOI
SyPRID: Two deep-sea sampler filters (white) are removed from their protective housings (gray) after a successful dive. Credit: Michael Jukuba, WHOI
Mitraria: This larva of a polychaete (segmented) annelid worm swims using a ciliated band. A bundle of long protective bristles protects its posterior. The juvenile develops inside the larval body and eventually emerges through a drastic metamorphosis. Credit: Laurel Hiebert
Nectochaete 1: In this nectochaete larva of a polychaete annelid worm, each segment bears setae, or bristles. Credit: Laurel Hiebert
Advertisement
Nectochaete 2: The larvae of some nectochaetes have more elaborate setae. In this case, the larva was rolling up into a ball with setae pointing outward, perhaps for protection from perceived predators. Credit: Laurel Hiebert
Cyprid: This larval form of a barnacle called cyprid is very mature. It has antennae and cement glands that enable it to walk around and attach to a rock or another suitable object. Credit: Laurel Hiebert
Glottidia: Both the larvae and adults of this inarticulate brachiopod group have two large valves (shells) that protect filter feeding–tentacles inside. The cilia-covered tentacles extend so the larva can swim. Credit: Kara Robbins
Veliger: This larva of a bivalve mollusk looks just like the adult. A double-ciliated lobe called the velum is tucked away in the shell. When extended, the velum resembles two wings and allows the larva to swim. Credit: Laurel Hiebert
Advertisement
Planula: A planula is the zeppelin-shaped larval stage of some cnidarians, including sea anemones and corals. They rotate slowly as they swim, eventually developing tentacles on the trailing end and attaching to the seafloor with the leading end. Credit: Laurel Hiebert
Brittle Star Juvenile: This brittle star has just changed into a juvenile, perhaps while it was being collected. Credit: Laurel Hiebert
![Little Creatures of the Deep [Slide Show]](https://static.scientificamerican.com/sciam/cache/file/87A712ED-C3E7-470D-849463967BA372CB.jpg?w=590&h=393)
