Nudibranch – The Jewels Of The Sea
Our oceans represent the most diverse ecosystem in the world. The aquatic creatures that inhabit their waters have an enormous variety of colors, shapes, feeding methods and defenses to ensure their survival. This environment is home to the most eye-catching and rarest organisms you can imagine, from translucent beings to deep-sea fish with organs that emit light. However, the jewels of the sea are the nudibranchs that we want to tell you more about today.
Sea slugs
Nudibranchs are also popularly known as sea slugs. They are molluscs (such as mussels and squid) belonging to the snail class that inhabit the surfaces of the seabed. Their name actually stands for “bare gills” because the gills of these animals are exposed in the form of feathers on their backs.
The nudibranch and its general characteristics
The most outstanding peculiarity of these beings is the variety of colors and shapes that they have. During the larval stage, these organisms have an embryonic shell that they lose as adults.
As a result, the adult snails do not have a shell and are quite similar to the land snails we all know. They move around thanks to a muscular foot that releases a slimy substance that allows them to support themselves and move on the substrate.
Since these animals are blind, their eyes only serve to distinguish light from darkness. At the same time they have two antennae, so-called rhinophores. These “horns” act as sense organs, allowing them not only to recognize food, but also to find other nudibranchs to mate with.
Due to the lack of a shell to protect other animals, these organisms must use different techniques to defend themselves against predators. For example, the secretion of highly toxic compounds. Because of this, some species are very poisonous.
Size and living space
Usually these creatures are benthic, which means they live on the surfaces of the sea floor. Others are pelagic and move in the shallower columns of salt water. As far as their size is concerned, they vary greatly, as there are nudibranchs that are only a few millimeters in size, while others reach a length of almost 40 centimeters.
Reproduction and nutrition
These mollusks are hermaphroditic, that is, they are male and female at the same time. They need another individual to reproduce, and when they find one, they fertilize each other.
They feed on other invertebrates, which makes them carnivores. Observations have also shown that they include algae and coral in their diet and even eat other nudibranchs or their eggs. They catch their prey with the help of the radula, a structure with small teeth that resides in the mouth of these mollusks.
Some species collect spine cells from polyps or sponge needles. They then integrate these into their bodies and can use them to defend themselves later.
Variety of colors and shapes
There are more than 3,000 known species of nudibranchs that inhabit all of the planet’s oceans. They live in both warm and cold waters and at different depths. However, scientists suspect that there are 3,000 other species that they have not yet discovered.
What stands out most about these beings is the variety of shapes (they can be smooth or rough, flat or fleshy, and long or short) and also the coloration they have. However, one should be careful when dealing with these wonders of the marine ecosystem, because this variety of colors warns of their danger. Most of the species are poisonous.
Therefore, these animals are a clear example of aposematism, also known as warning coloring, a defense system in which a deterrent property is linked to a warning signal. In addition, they are endowed with numerous structures and features that help them go unnoticed by their predators:
- Homochromy. Their shapes and colors allow them to camouflage themselves as aquatic plants and seem to merge with the environment.
- Needles or spikes. These needle-like extensions on the body help them defend themselves. You acquire some of them from the sponges that they eat.
- Release of toxic biological products that make them toxic.
- Bad taste. Since nudibranchs don’t taste good, predators know that they shouldn’t eat them again once they’ve tried them.
Some curiosities about nudibranchs
There are many different species within the nudibranch group. Some are harmless but mimic the appearance of poisonous species to appear dangerous:
- Blue ocean snail (Glaucus atlanticus) : The blue ocean snail has an amazing coloration and a very strange appearance. However, it is the deadliest species there is.
- Elysia chlorotica : This specimen can photosynthesize thanks to the chloroplasts of algae it eats. The chloroplasts carry out photosynthesis with solar energy and the nudibranchs feed on the products of the same.
- Ceratosoma gracillimum : The Indonesian ceratosoma lives in symbiosis with an emperor shrimp , which keeps it clean. In return, the nudibranch transports the king prawns and makes it easier for them to get food.
Nudibranch – a real feast for the eyes!
As you can see, the marine ecosystem is incredibly diverse. And of all the organisms that live in it, the nudibranchs ( despite their methods of camouflage ) certainly do not go unnoticed. These jewels of the sea are a real feast for the eyes.
Thanks to the heterogeneity of their appearance, shapes and colors, they are certainly unique beings. Their characteristics show that size is ultimately not an obstacle when an animal has the most effective strategies and the most convincing defense mechanisms.
Finally, we want to mention that the same methods that allow them to hide from their predators also make them difficult to find and identify.
