The Humboldt squid (Dosidicus gigas) have a complex system of bioluminescent signals, although most of the time in the dark, reported in the Proceedings of the National Academy of Sciences. Their intentions (e.g., that they are going to hunt) squid is able to Express all sequences of signals.
When the light level is high, the animals can quickly and efficiently exchange information in the form of visual signals. However, in the ocean at great depths there is virtually no light, so visual communication is unlikely to play a major role for species that live there.
The probable exception is the squid. Those species that live in relatively shallow depths, there is a fairly complex system of visual signals. And these squid, and deep sea are prone to cannibalism, so they need to quickly identify the presence of other individuals. Finally, many molluscs this group of social and is able to coordinate their actions, being in large groups of relatives. Given all this, we can assume that species living at a considerable depth, too, have the developed system of visual communication — but they are practically not studied.
Benjamin Burford (Burford Benjamin P.) from Hopkins Marine station of Stanford University and Bruce Robison (Bruce H. Robison) from the Research Institute Aquarium Monterey Bay in the field have studied the behavior of the Humboldt squid. It is a large predatory deep-sea clams, which are kept in groups. It is known that during the hunt they luminesce in red, but this is not the only visual signal repertoire of the calamari.
The aim of the researchers was to link the various signals clams with defined behaviors and to write them into an environmental context. To this end, they videotaped the behavior of Dosidicus gigas from 2005 to 2012. Cameras operated remotely, so the squid was not afraid of them and hunted, not floating away, far away.
All records selected 30 of the most qualitative that have a different number of squid and at least one of them was completely visible in the frame at least 14 seconds. For each record selected one such individual and analyzed what she was doing in this period, both painted different parts of her body, how many individuals of the same species surround it.
It turned out that the behavior of the Humboldt squid depends more from the light (bioluminescent) demonstrations neighbouring shellfish than from their POS. Being in large groups of D. gigas are often “flash” (the intensity of luminescence increases sharply) or “flicker” entire body.