Pelagothuria natatrix Facts: The Jellyfish-like Swimming Wonders of the Deep

Beneath the ocean’s surface lies a fascinating and unconventional creature: Pelagothuria natatrix, a sea creature that challenges conventional norms. Join us as we explore the extraordinary world of this enigmatic marine species and uncover the secrets that make it truly one-of-a-kind. 

Pelagothuria natatrix
Scientific name: Pelagothuria natatrix
Phylum: Echinodermata
Class: Holothuriidae
Order: Elasipodida
Family: Pelagothuriidae
Genus: Pelagothuria

1. They’re not a jellyfish

Look like jellyfish, Pelagothuria natatrix is actually a type of sea cucumber. Like the pink see-through fantasia, this species is also a member of the family Pelagothuriidae.

In contrast to typical sea cucumbers, this species doesn’t have a cucumber shape. Its appearance resembles a jellyfish instead. Its notable characteristics include a sizable umbrella-like swimming structure, which is upheld by around 12 highly adapted oral tentacles. The creature possesses a small, tapered body and assumes a swimming posture with its mouth positioned on top. It has a size of about 16 cm in length.

The Pelagothuria natatrix possesses a translucent body adorned with a delicate, pale purple hue. Approximately 15 short feeding tentacles encircle its mouth, akin to those found in other sea cucumbers. The swimming sea cucumber possesses a retractable veil, akin to a jellyfish with a broken mid-ventral radius.

Despite its initial identification in the late 19th century, the Pelagothuria natatrix has remained an enigma for an extended period due to its delicate and gelatinous composition. Its distinct attributes and elusive behavior still captivate scientists fascinated.

2. Habitat 

Pelagothuria natatrix, an exceedingly uncommon species of sea cucumber, boasts a vast geographical distribution, spanning across the Pacific, Atlantic, and Indian Oceans. This remarkable creature thrives at remarkable depths, ranging from 200 to 4,433 meters below the ocean’s surface.

3. Pelagothuria natatrix Adaptions

The enigmatic survival strategies employed by the swimming sea cucumber in the face of harsh and challenging conditions have continued to baffle and intrigue researchers for years. In their relentless pursuit of unraveling the mysteries of the deep-sea world, marine biologists have uncovered some fascinating insights into the extraordinary adaptability of this mysterious creature.

One of the most remarkable features of Pelagothuria natatrix is its jelly-like body composition, which has proven to be of utmost significance in its ability to thrive in its deep-sea habitat. Its body is composed of water with a relatively small amount of collagen. This composition allows the creature to minimize energy for production and maintenance. This makes it perfectly suited for their survival in an environment where food is scarce.

The Pelagothuria natatrix swimming

Furthermore, this composition allows the creature to maintain its buoyancy and move effortlessly without wasting valuable energy and oxygen on continuous swimming. It also provides the sea cucumber with an extraordinary level of flexibility, enabling it to maneuver through tight spaces and crevices with ease.

When faced with potentially harmful situations or approaching predators, the creature has the remarkable ability to contract its body, reducing its surface area and effectively minimizing the impact of external forces. This remarkable defense mechanism not only shields the sea cucumber from potential harm but also allows it to retreat into the safety of narrow cracks and crevices, effectively escaping danger.

The Pelagothuria natatrix swim along the ocean, finding food

Pelagothuria natatrix is predominantly a swimmer, utilizing the web around its mouth to propel itself through the water column.

4. Diet and reproduction

Pelagothuria natatrix eats suspended particles drifting in the water column before these food particles reach the seabed where their settled counterparts are waiting. Furthermore, it sustains itself by consuming resuspended sediments and detrital matter from shallower depths.

The swimming sea cucumber Pelagothurianatatrix

Basically, they reproduce like other sea cucumbers. The spawning and fertilization take place externally as males and females release their gametes into the ocean.

Throughout their life cycle, they go through several developmental stages. Initially, the embryos mature into planktotrophic larvae known as auricularia. These larvae then undergo a transformation into a barrel-shaped stage called doliolaria, and ultimately, they metamorphose into juvenile swimming sea cucumbers.



I'm so fascinated about animals and want to share with you these amazing, interesting, amusing and beautiful creatures. Hope you enjoy it!

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