This little siphonophore has a big impact on deep-sea food webs.
Siphonophores (pronounced “sigh-fawn-oh-fours”) are delicate drifters made up of specialized segments that work together as one. These animals are like living commuter trains. Pulsing bells up front pull a long chain of segments specialized for feeding, defense, and reproduction.
Siphonophores are deadly beauties—they cast a net of tentacles to snare prey and are important predators in ocean ecosystems. In Monterey Bay, the common siphonophore (Nanomia bijuga) is one of the principal predators of krill. At times, this species can be quite abundant. Combined, the numerous Nanomia eat more krill than all the whales that gather to feast in the bay’s fertile waters.
This small siphonophore—only about 30 centimeters (12 inches) long—is a sit-and-wait predator. It casts stinging tentacles that are lined with knobby tips. Those bumpy bits resemble tiny shrimp-like creatures, making tasty bait for hungry plankton. But Nanomia is not a very patient predator. If nothing comes along in a few minutes, it retracts its tentacles and swims to another spot to try again.
Maximum size: 30 centimeters (12 inches)
Depth: surface to 700 meters (2,300 feet)
Habitat: open ocean and midwater, including the twilight (mesopelagic) zone
Diet: plankton, especially krill
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