The ocean’s surface may appear to be boiling on a calm nite in the North Pacific, somewhere in the convergence zone where the warmer Kuroshio Current water meets the colder subarctic gyre. In reality, hundreds of squid are coming from the depths to feast on the tiny fish and crustaceans that congregate at the cold-water barrier. They move so quickly that their arrival is more noticeable as a commotion than as individual animals. The neon flying squid doesn’t make an announcement. It simply shows up at the surface in numerical form, carrying out its intended function.
From the waters south of Japan and along the Aleutian chain eastward toward the central and eastern Pacific, as well as thru the Southern Hemisphere, Ommastrephes bartramii inhabits a vast area of the Pacific. It’s one of those animals that marine biologists characterize as plentiful and ecologically valuable, but they also acknowledge that there is still much to learn about how it behaves in the open ocean. The daily rhythm—daytime hours spent below 300 meters, avoiding light and the visual predators that exploit it, and nocturnal hours spent in the upper layers, feeding vigorously on whatever the cold-current boundary has concentrated there—is well established. For an animal with a one-year lifespan, this diel vertical migration—many hundred meters each way, twice a day—is taxing by any metabolic reckoning.
Beyond the typical bounds of cephalopod biology, this species is notable for its flight habit. The squid’s reaction to a committed pursuit run by a swift predator, such as a swordfish, mahi-mahi, or tuna, is not to outwit the assailant. Researchers have estimated the distance it goes thru the air—between 10 and 20 meters—before reentering the water after it releases water thru its siphon with enough force to send itself clear of the surface and unfolds its fins into a gliding posture.
Although the mechanics of this are not entirely understood, the physics are generally understood: the squid’s body shape, which is more tapered than round, allows it to maintain a stable glide rather than tumble instantly, and the siphon acts as a rocket exhaust, producing thrust that overcomes gravity long enough for the fins to extend and provide lift. Flight is not powered. But compared to just jumping, it’s far more controlled.
This is more intriguing than a single escape technique because it seems to occur in unison. Neon flying squids are social animals that travel and hunt in groups. Several observations have shown what appear to be simultaneous or nearly simultaneous launches from a group under threat, with dozens of squid breaking the surface at once, creating the kind of scene that fishermen and sailors describe in terms that don’t initially sound biological. Less research has been done on the social aspect of their behavior than on migration or flight mechanics, but what is known about schooling behavior in fish species under comparable predation pressure is generally consistent with the idea that the group offers some protective function beyond what individual animals could accomplish alone.
The detail that pushes everything else into a new frame is the one-year lifespan. A long-lived predator operates under considerably different limitations than an animal that reproduces, reaches adulthood, and dies within a year. Within that short time frame, all caloric investments in flight, migration, and social behavior must be profitable. Because the populations refill every year, the species is extremely sensitive to environmental conditions.
Unlike longer-lived species that can withstand single-year fluctuations, a warm-water year in the North Pacific alters recruitment in ways that manifest nearly immediately in catch rates. Ommastrephes bartramii’s ability to quickly track favorable conditions, expand in good years, and contract in bad ones without the generational lag that restricts how quickly a longer-lived species can respond may contribute to its widespread abundance.
