Glowworm Nautilus

Another entry from the Zhang Temporal Expedition to the Devonian.
This is the Glowworm Nautilus (Velabrachius lucifer)
The female of this species possesses two extra-long arms with sail-like flaps called vela (the name is singular and plural), which she clamps along the sides of her loosely- coiled shell to form a chamber. Eggs are deposited into this chamber, and the larvae remain within until they are large enough to survive on their own. Males are similar in size, though they do not possess the long arms nor the vela.
Both male female V. lucifer possess bioluminescent organs, called photophores, along their arms. Glowworm Nautili can "wink" their lights on and off, producing flashing patterns, probably as a form of communication.
For more details, see: Irvine, Gene The Luminous Sea: A Bioluminescent Nautiloid from the Middle Devonian (2011) Journal of Cephalopod Studies 134:45 pgs. 345-362

The brood chamber of the female nautilus often serves as a refuge for other pelagic animals. Check them out here: [link]

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