Resomia ornicephala by MBARIMonterey Bay Aquarium Research Institute
Historically, gelatinous animals have been challenging to study. Their delicate nature makes them difficult to collect, especially from the ocean’s depths. By using deep-diving robots—remotely operated vehicles, or ROVs—MBARI and our collaborators are revealing the dazzling diversity of delicate drifters that lies beneath the surface.
Blue siphonophore, Gymnopraia lapislazula (2005) by MBARIMonterey Bay Aquarium Research Institute
Gymnopraia lapislazula
Haddock, Dunn, and Pugh, 2005
In 2005, MBARI and our collaborators described two unique siphonophores from the twilight depths of Monterey Bay. The two species aren’t closely related, but both have striking colors. Gymnopraia lapislazula has sparkling blue iridescence when illuminated with white light.
Green caterpillar siphonophore, Lilyopsis fluoracantha (2012) by MBARIMonterey Bay Aquarium Research Institute
Lilyopsis fluoracantha
Haddock, Dunn, and Pugh, 2005
The second species, Lilyopsis fluoracantha, becomes bright green when lit by blue light. Scientists think that the siphonophore’s fluorescent proteins interact with the chemical pathway involved with creating bioluminescence. The proteins shift the color to a green glow.
Red siphonophore, Marrus claudanielis (2003) by MBARIMonterey Bay Aquarium Research Institute
Marrus claudanielis
Dunn, Pugh, and Haddock, 2005
Marrus claudanielis is an especially delicate drifter. It’s sensitive to light, so if we’re not careful, the lights on MBARI’s robotic submersibles can cause the animal to shed its body parts. With observations off both coasts of North America, this species appears to be widely distributed, but has simply eluded scientists in the past—likely due to its fragile nature.
Siphonophore, Resomia dunni (2015) by MBARIMonterey Bay Aquarium Research Institute
Resomia dunni
Pugh and Haddock, 2009
Resomia dunni has a few large stinging arrays that drop off very easily. We don’t yet know what prey these special structures are targeting. This species is named after MBARI collaborator Casey Dunn, for his contributions to siphonophore phylogeny, taxonomy, and biology.
Siphonophore, Resomia ornicephala (2005) by MBARIMonterey Bay Aquarium Research Institute
Resomia ornicephala
Pugh and Haddock, 2009
Resomia ornicephala has lures on its tentacles that look like leaves. This species is found in a narrow depth range around 210 meters (690 feet). Researchers think their depth range is related to the fluorescence of their lures—the dim blue light at those depths would make an excellent backdrop for the fluorescence to be visible to krill, their primary prey.
Siphonophore, Resomia persica (2017) by MBARIMonterey Bay Aquarium Research Institute
Resomia persica
Pugh and Haddock, 2009
Resomia persica has very delicate tentacles. It must capture zooplankton using a powerful sting rather than hauling them in with strength.
Siphonophore, Sphaeronectes christiansonae by Steve HaddockMonterey Bay Aquarium Research Institute
Sphaeronectes christiansonae
Pugh, 2009
Some of the most simple and elegant siphonophores are in the genus Sphaeronectes. This group has no float and only one swimming bell. Video footage from MBARI’s robotic submersibles helped scientists describe three new species of Sphaeronectes. S. christiansonae was named after MBARI researcher Lynne Christianson and S. haddocki after MBARI scientist Steve Haddock. S. tiburonae was named after one of MBARI’s submersibles which collected many of the specimens for study.
Woolly siphonophore, Apolemia lanosa (2005) by MBARIMonterey Bay Aquarium Research Institute
Apolemia lanosa
Siebert, Pugh, Haddock, and Dunn, 2013
Members of the genus Apolemia are some of the longest animals on the planet. This makes it a challenge to collect more than fragments. A. lanosa was named for its shaggy appearance—the species name “lanosa” derives from Latin “lana” and means “woolly.”
Red-grooved siphonophore, Apolemia rubriversa (2003) by MBARIMonterey Bay Aquarium Research Institute
Apolemia rubriversa
Siebert, Pugh, Haddock, and Dunn, 2013
For decades, there was only one species name that was used for all Apolemia. The description of A. lanosa and A. rubriversa by MBARI researchers and our collaborators is a first step toward organizing the full diversity of this group of siphonophores.
Angler siphonophore, Erenna sirena by MBARIMonterey Bay Aquarium Research Institute
Erenna sirena
Pugh and Haddock, 2016
Siphonophores in the genus Erenna are fish predators. They are only found quite deep, where fish might be scarce. To improve their ability to attract prey, Erenna species use glowing bioluminescent lures, which they flick and wriggle to wriggle to entice fish. The lures are different between each species, and are the easiest way to distinguish them.
Shaggy siphonophore, Erenna insidiator (2015) by MBARIMonterey Bay Aquarium Research Institute
Erenna insidiator
Pugh and Haddock, 2016
Erenna insidiator is a rare find—MBARI has only spotted this species twice. We still don’t know a lot about its biology, but believe it ambushes its prey with elaborate lures like other siphonophores in the genus Erenna.
Siphonophore, Kephyes hiulcus by Steven HaddockMonterey Bay Aquarium Research Institute
Kephyes hiulcus
Grossmann and Lindsay, 2017
Sometimes, sorting out species names is more of a history project than a biology project. This species was first discussed in the literature in 1861, and given five different names over the years.
Siphonophore, Tottonphyes enigmatica (2010) by MBARIMonterey Bay Aquarium Research Institute
Tottonphyes enigmatica
Pugh, Dunn, and Haddock, 2018
When researchers first saw Tottonophyes, they weren’t quite sure which other siphonophores were its closest relatives. It had features that were between two of the known groups, inspiring the name T. enigmatica. The genus is a tribute to A.K. Totton, who described many species and helped synthesize knowledge about siphonophores.
We’re always learning more about the deep sea
In 34 years of deep-sea exploration, we’ve still just barely scratched the surface in understanding life in the largest living space on Earth. Each dive into the inky depths reveals something new and unexpected.
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