Guide of the Algarve Sea Slugs
One of the areas of greatest interest within the area of diving in the Algarve is that of Sea Slugs. Due to their diversity - with more than 150 species found in the Algarve of various colours, shapes, sizes and characteristics - Sea Slugs delight divers, whether they are photographers or just interested admirers.
With the aim of promoting diving in the Algarve and enjoying interest in the beauty of Sea Slugs, Subnauta has published the Guide to Sea Slugs in the Algarve, a book written by Gonçalo Calado and João Pedro Silva.
Here is an outline of the chapters the Guide consists of.
“Even at the start of their voyage of discovery, any recreational diver will have had the privilege of observing sea slugs, known in the scientific world as Opistobranchia. These organisms, which form part of the sea snail or sea worm family, often have striking colours and extravagant shapes that few people ever feel indifferent to. Their beauty and grace in the water is comparable to that of butterflies, to use a comparison from dry land.
Sea slugs are molluscs, like octopus or clams, but they have more in common with whelks, snails and land slugs, which are gastropods. They have the use of one large foot in common but evolutionary pressures were different many millions of years ago. In sea slugs, we can see adaptations that are unique in the animal world and capable of intriguing any zoologist.
In continental Portugal, close to 150 species of sea slug are known, the great majority of which have been observed in the Algarve. Sea slugs possess many curious evolutionary aspects. Some species are notable for their capacity to retain the chemical composites of their captures and use them for defensive reasons (sponges, ascidias, algae, etc.). Certain groups manage to retain some of the cell structures of the algae they consume (chloroplasts – the most important structures for photosynthesis) and keep them functional within their own cells, thus producing part of their own food through the photosynthetic process, just like a plant.
Others can store stinging cells from the anemones they consume, keeping them ready to be used in the most vulnerable parts of their body on a potential predator. Some have such an extraordinary ability to mimic the environment in which they live that they can easily go unnoticed, making their observation and identification an additional challenge.”
Gonçalo Calado and João Pedro Silva – João Pedro Silva Photographs - Subnauta Publishing.