McCoy’s nautiloid lab companion, Prodromus
The beautiful objects popularly miscalled Paper-Nautili should not really be compared with true shells, like that of the Nautilus, to which the inhabitant is fixed by organic attachments, without tearing which or destroying the life of the Cuttle-fish it would be impossible to separate them.
The Argonaut, or Paper-Nautilus, is always excessively thin, white, imperfectly calcified, so as to be slightly flexible when fresh, and totally unconnected with the Octopus inhabiting it; so that the so-called shell may be dropped if the Cuttle-fish be frightened, without injuring any of the soft parts of the animal.
Like all the Octopoda, the Argonauts are generally nocturnal, and inhabit the high seas, feeding on various floating small animals; rarely coming near the surface by day, except in calm weather.
The females only approach the shallow waters of the coast in summer time, when the eggs are developed.
It is in the hottest months of summer (January, February, and March), especially in the last few years, that they appear on the shore of Hobson's Bay, near Brighton, where the several specimens of the animal and the shell together have been obtained.
The individual figured was given to me by a young friend (who requested that his name not be mentioned), and was kept alive in a large tub of sea-water for a considerable time.
Nothing could be more ludicrously interesting than the vigilant look-out which the creature maintained, watching suspiciously, with its large perfect eyes just peeping over the edge of the shell in which it nestled, as represented in our plate, with the arms often curled inside along with the body when at rest; at other times they hung outside or streamed in a close group in front, when the animal and shell darted backwards by shooting water out of the funnel in front of the head.
Occasionally it crawled about on the bottom, head downwards, with the shell covering over its upper part. When greatly frightened it abandoned its shell and darted away with great velocity, but got back into it again when left alone.
The colors varied in a few seconds from the palest pink to rich madder purple, according apparently to the will or temper of the creature.
The specimens figured are from rocky parts near Brighton, but the so-called shells are found occasionally on all parts of the coast of the colony.
- Frederick McCoy