One of my favorite animals is the little sepiolid squid found in the Pacific Northwest, Rossia pacifica. So…
I thought I would just post a few images of this wonderful small squid. The next two images were taken sequentially as rapidly as my strobes would recycle. The color change occurring in response to the strobe’s flash was impressive and “instantaneous.”
Rossia pacifica, in one of my research localities.
A Rossia that has changed color in response to my strobes. This is the same individual shown in the preceding image.
The animal below saw me coming and watched me. It moved a bit but not too much as I approached, presumably a predator, such as a dog fish (Squalus) would try to catch a swimming squid, and . When I got about a meter away, it turned “white;” at the ambient light at that depth it really just matched to bottom color.
A Rossia that "went white" when it saw me approaching. NOT a happy critter!
Individuals of Rossia have a very stereotyped escape response. It appears to be a response to slow patrolling predators on the bottom fauna, particularly dogfish sharks. The sepiolid lauches from the bottom and swims about 30 to 40 cm above the bottom more-or-less in a straight line inking every few meters. When it should ink the last time, it doesn’t, but it turns dark, throws its arms up in a “scatter” posture and drifts like an ink blot until it hits the bottom, whereupon it bleaches (which makes it effectively disappear) and rapidly covers itself with sediments.
Rossia in its "drifting" posture. This posture will occur prior to the animal dropping to the bottom and covering itself with sediment.
This is an ink blot made a swimming "escaping" Rossia. Unfortunately, the sediment in the water obscures it somewhat, but it mantains a coherent shape roughly that of a swimming squidlet.
Rossia drifting and mimicking an ink blot. It has already inked a couple of times, and is not actively swimming, but is just drifting in the current.
After the successful escapes, eventually eggs are laid and after several months they hatch. The first image is of an egg clutch. The next two are of a newly-hatched, itsy-bitsy, baby Rossia.
Rossia pacifica egg capsules on an old discarded coffee mug. The capsules are about a centimeter long.
A newly-hatched Rossia. Less than a 1 cm long, this animal is probably only a few days post hatching..
A baby Rossia swimming. When this color pattern occurs as the animal is swimming, it effectively "disappears" and becomes very cryptic as it swims or drifts over the substrate.
This last image is of a Rossia watching me as I took its picture. Who could resist those eyes?
A Rossia watching me; it was about 2.5 centimeters (1 inch) long.
Tags: behavior, ecology, egg capsules, escape response, hatching, invertebrates, marine biology, natural history, Rossia, sepiolid, Washington