Mysterious jellyfish pulses through Lake Merritt

This jellyfish pulsed through Lake Merritt early Monday morning. (KTVU FOX 2)

A rower captured video of a jellyfish propelling through Lake Merritt Monday morning.

While the sight of the invertebrate itself is captivating, experts don't seem to agree on the species of the aquatic creature. 

Nate Jaros, senior director of fish and invertebrates from Long Beach's Aquarium of the Pacific, shared with KTVU that it appears it could be the clinging jelly, Gonionemus vertens.

"Without a thorough examination of the anatomy, the identification of most hydrozoan sea jellies—like the clinging jelly—is challenging," Jaros shared.

An expert from the Marine Science Institute noted that the organism appears to be similar to Craspedacusta sowerbii, a type of freshwater jellyfish.

An environmental program manager with the state Department of Fish and Wildlife suggested that it may be a Maeotias marginata, which are non-native but commonly found in brackish water in the Bay and Suisun Marsh.

The 14-second video shows the sea creature drifting through the lake before suddenly pulsing rapidly. The jellyfish is characterized by the whitish X-shaped marking across its hood and mid-length tendrils.

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Just earlier this May, a leopard shark was spotted in Lake Merritt. Sea lions, bat rays, and other marine life have also made appearances throughout the natural brackish-water lake, which is part of a salt marsh system.

Plus, last year, a new "stunning and unusual" species of jellyfish was discovered in the depths of Monterey Bay.