Keegan Rankin previously worked as an AmeriCorp/Kupu Intern in 2022 on Kuaihelani and ended up documenting and researching invasive species along with cataloging native marine species. Today, Keegan works as a Seabird Protection Project Volunteer caring for native species above water on Kuaihelani but spends off-hours underwater. Keegan once noted that, “our oceans and the life in them have made me into the person I am today. . . in all that I do, I strive to remember that we are all linked together by the sea, and our actions in one place can impact the lives of others elsewhere.”
More about the The Pelagic Sea Slug, Glaucus atlanticus
The Pelagic Sea Slug is a nudibranch and it is holoplanktonic in nature meaning they live out in the open ocean, far from the reefs, for the entirety of their lives. It is a sea slug (or aeolid nudibranch) that has horn or finger-like growths called cerata, which cover their entire bodies or along the sides of the body. The cerata contain cnidocytes which are stinging cells they use as a means of defense against predators.
Pelagic Sea Slug is found throughout the tropical and subtropical Atlantic, Indian, and Pacific Oceans and manages to stay afloat by swallowing air and storing air bubbles in their stomach. Their prey on marine animals including Portuguese Man-o-War, By-the-wind Sailor and hydrozoan polyps called Blue Button. This is where the slug also earns one of their other common names, the Man-of-War Sea Slug. The Pelagic Sea Slug uses cerata to grasp and manipulate their prey, or even to climb down their victim to reach more edible portions.
Not only using their prey for nutrients, but the Pelagic Sea Slug is also able to steal the explosive cells used by sea anemones, jellyfish and corals without causing them to fire and use them in their own defense. Called cnidocytes these cells pass through the stomach and are stored in the cerata.
In addition, limiting contact with their prey and protective cells lining the mouth, along with mucous, protect the Pelagic Sea Slug from being stung by their prey. Pelagic Sea Slugs are hermaphrodites, meaning that everyone possesses organs that can produce oocytes (eggs) and spermatocytes (sperm). Pelagic Sea Slugs are highly fecund, producing hundreds of free-floating egg strings containing thousands of eggs. Because the Pelagic Sea Slug lacks the adaptations necessary for free swimming and relies on the ocean currents to carry them to prey, producing a high number of eggs ensures that some offspring will live long enough to reach their first meal, which increases the odds that individuals will survive to reproductive age and contribute to the population.”