A new species of deep sea jellyfish, Crossota millsae evince sexually dimorphic differences in gonad morphology. They only reproduce sexually as medusa, never forming polyps, and are viviparous; females brood baby medusae attached to the gastric canals in the sub-umbrellar space. Unlike most hydromedusae, none of the Crossota have a sessile stage. They instead spend their entire lives in the water column as plankton.
The body is more fragile than in other species of Crossota. It can be distinguished from other species by its pigmentation, the location of gonads, and the arrangement of the tentacle abscission zone that leaves a characteristic undulating fringe of tentacular bases. Crossota millsae display a burnt-tangerine color on their innerbell and a bright pink to lavender color on the ring and radial canals, manubrium and gonads. This makes living specimens of this species difficult to confuse with any other known species of hydromedusa.
Found in North Pacific Ocean off California and Hawaii. Discretedepth sampling showed this species lives at depths below 1000 meters in both geographic locations.The species is more abundant off California than off Hawaii. The greatest population densities were found at ~2500 m off California and at ~1250 m off Hawaii.
"Eggs begin to develop within the ovary and burst out as small white spheres as they develop into juvenile medusae. More than one egg will develop at a time, and development can be sequential. The developing eggs change shape and color from white globular embryos to pink mushroom-shaped larvae as they mature. Small pink lipid droplets identical in size and color to those of the ovary and adult radial canals are apparent in the bell of the juveniles. The ring canal develops first followed by formation of radial canals. Juveniles reach almost 6 mm in length before separation from the mother. Juveniles begin to develop tentacles while still attached, but keep them curled up. They are probably able to start capturing prey as soon as they break away from the mother or perhaps even beforehand within the subumbrellar space. The manubrium maintains its stout appearance after separation. The pigmentation of juvenile individuals is composed of lavender droplets similar to the composition of the adult ovariesand radial canals. Once free-living, the apex of the juvenile bell develops a faint tangerine color that spreads downward during maturation. The presence of the lipid-like droplets in both the adult and juvenile suggests that nutrients are being transferred from the mother to juveniles." (Thuesen 2003)
Crossota millsae is a species of deep-sea hydrozoan.[1] These small ocean-dwelling creatures are bioluminescent; the light emitted by these jellyfish serves as a defense or warning to other creatures.[2] Males and females have both been described, and it reproduces sexually. They are viviparous and females brood baby medusae attached to the gastric canals inside the sub-umbrellar space.
Crossota millsae was first described from the Pacific Ocean off Hawaii and California.[1] It was subsequently found in the Arctic Ocean[3][4] and in Guayanilla Canyon off Puerto Rico.[5] NOAA researchers who filmed this species in 2018 near Puerto Rico called it a "psychedelic" jellyfish.[6] It lives below 1 km depth in all four regions. Its highest abundance is found at 2500 m off California and 1250 m off Hawaii. In the Arctic Ocean, it has been observed sitting on the seafloor.[7]
It was named after Dr. Claudia Mills, a marine scientist at the Friday Harbor Laboratories.
Crossota millsae is a species of deep-sea hydrozoan. These small ocean-dwelling creatures are bioluminescent; the light emitted by these jellyfish serves as a defense or warning to other creatures. Males and females have both been described, and it reproduces sexually. They are viviparous and females brood baby medusae attached to the gastric canals inside the sub-umbrellar space.
