3 mysterious inhabitants of the ocean depths, which you will definitely want to know more about (13 photos + 3 videos)
The natural world is full of incredible creatures, each unique in its own way. 
Like these amazing inhabitants of our planet. Which of them hides in the depths of the ocean, which floats on the waves, and which seems like an alien? From the mysterious reefs of the Great Barrier Reef to the clear waters of the open ocean, these creatures capture the imagination with their beauty, danger, and important role in the ecosystem.
1. Salps – Mysterious Aliens of the Ocean 
If aliens decided to settle in our oceans, they would probably look like salps. These amazing sea creatures from the Thaliacea class look more like spacecraft than living creatures. Transparent, gelatinous and almost invisible in the water, salps seem to have arrived from another world. But despite their ethereal appearance, these creatures play a vital role in the ocean ecosystem. 
Salps, which belong to the tunicate class, are relatives of more well-known animals such as jellyfish and sea cucumbers, but their lifestyle is much more interesting. They move according to the principle of water pumping: they draw water through their body, filtering plankton from it. In a day, one salp is able to pass through itself a volume of water equal to its own weight multiplied by hundreds. This makes them real ocean cleaners that maintain balance in its depths. 
However, the most interesting fact about salps is their unique reproduction. They can reproduce both asexually and sexually, creating entire chains of offspring. The asexual generation forms long colonies, where each individual is connected to its neighbors, resembling a living train. When the time comes for sexual reproduction, salps release eggs, from which new forms emerge, ready to begin the cycle anew. The combination of sexual and asexual reproduction through alternation of generations is probably associated with high mortality from numerous enemies. 
Despite their inconspicuousness, salps have a huge impact on the planet's climate. By filtering water, they absorb carbon dioxide from the atmosphere and remove it to the depths after their death. Thus, these little aliens help slow down global warming.
2. Spotted bat - a mysterious inhabitant of the Great Barrier Reef
In the world of oceans there are creatures that are so rare and mysterious that their appearance becomes a real event for scientists and lovers of marine life. One of such creatures is the spotted bat (Chirodectes maculatus) - an amazing creature that still remains one of the least studied inhabitants of coral reefs.
Bat are representatives of the class of box jellyfish, known for their unusual body shape and slow, smooth movements, reminiscent of hand movements. The spotted bat was first described only in 2006, and since then it has been observed only a few times. This makes it one of the rarest species inhabiting the tropical waters of Australia.
This species is distinguished by its bright coloring. The body is covered with characteristic dark spots. The size of the spotted bat is small. Usually it reaches 10-15 centimeters in length. However, its appearance and behavior attract the attention of even the most experienced researchers.
The spotted bat has been seen in only one place - at the northern end of the Great Barrier Reef, near Australia's Lizard Island. This region is famous for the richness of its marine fauna, but even here the bat remains a rare guest. Scientists suggest that this species may be endemic, that is, it lives exclusively in this area.
Its habitat is coral reefs, where it hides among thickets of soft corals and sponges. Thanks to its camouflage coloration, the chirodectes is almost invisible against the background of the environment, which helps it avoid predators.
Like other members of the chirodect family, Chirodectes maculatus leads a sedentary lifestyle. It prefers to lie in one place, waiting for small fish or crustaceans to swim close enough to attack them. Its hunting method resembles the tactics of predators such as frogfish or stonefish: surprise and speed.
The spotted bat is not just a rare creature. Its existence highlights the importance of preserving the Great Barrier Reef ecosystem, which is under threat from climate change, water pollution and other anthropogenic factors.
The spotted bat is also a living reminder of how much remains unknown in the ocean depths. Its discovery in 2006 was a real scientific breakthrough, and each subsequent observation adds new pages to the history of studying marine life.
3. Physalia physalis - a ship with poisonous tentacles
There are creatures in the ocean that simultaneously delight with their beauty and inspire respect with their danger. One of these creatures is the Physalia physalis, also known as the Portuguese man-of-war. Despite its poetic name, this sea creature is not a jellyfish, but a complex organism capable of paralyzing prey and even threatening human life.
Physalia physalis is a representative of the order siphonophores, but unlike ordinary jellyfish, it is a whole colony of organisms working as a single whole. Its body consists of several types of polyps, each of which performs its own function: some are responsible for nutrition, others for reproduction, and others for protection.
One of the most noticeable parts of the physalia is its gas bladder, reminiscent of a ship's sail. It is thanks to this bubble that it can drift along the surface of the water, using the wind to move. However, the real danger is hidden under the water - long tentacles, strewn with stinging cells that secrete a powerful poison.
Physalia physalis is found in the warm waters of the Atlantic, Indian and Pacific Oceans. It is especially common in tropical and subtropical regions, where the water temperature promotes its active movement. Thanks to its sail, physalia can cover huge distances, obeying the winds and currents.
The main diet of physalia consists of small fish, shrimp and other marine organisms. When prey touches its tentacles, the stinging cells immediately release poisonous threads that paralyze the victim. The prey is then pulled toward the oral polyps, where it is digested.
An encounter with the Physalis physalis can be painful and even life-threatening. Its venom contains neurotoxins that can cause severe pain, reddening of the skin, swelling, and even anaphylactic shock in sensitive individuals. Although fatalities are rare, they do occur, especially if the person is far from the shore or does not receive timely medical care.
Despite its danger, the Physalia physalis plays an important role in the ocean ecosystem. It is food for some marine animals, such as turtles and certain species of fish, which have learned to evade its poisonous tentacles. In addition, its presence in the ocean helps control the number of small organisms, preventing their excessive reproduction.
