Running to the shelters!

.........................The presence of Elina alerts the hermit crabs.

As the naturalist approaches the sponge,he can notice a lot of tiny shells loosing their balance and falling down. In previous posts we saw the symbiosis (or the vicinity) between the sponge, mollusks and polychaeta. The structure of the sponge Aplysina aerophoba provides shelter also to the third major group of benthic fauna, the crustaceans. The little shells (except some Bittium sp) are the houses of the small hermit crabs. In the macro photo I think that you can see a young Pagurus anachoretus but it is too small to recognize. I was very impressed by the fast and simultaneous reaction of the tiny hermit crabs. As I got close to the sponge, at once all of them left their shell to fall from the walls of the sponge to the lower darker parts of the sponge. I don’t know if there is a possibility of communication between the hermit crabs, but what about the sponge? Sponges don’t have nerves but as an animal they find other ways to inform the rest of the body for what is happening. Maybe there is a sign by the sponge that can be recognized by the crabs? It’s very difficult to know but it’s nice as a scenario. Who knows maybe we learn in the next posts of the blog.

.......................................finally a successfull pic of the tricky hermit crabs!

Tiger Year Vs Valentine Day

The Chinese lunar calendar rolls in as the Year of the Tiger, quite ironic if you

consider that the South China Tiger is listed as one of the world's 10 most

endangered animals with only a few thousand remaining in the wild.

Human activity has all ready decimated 3 sub-species of tiger....

Valentines Day, the day of love and affection finds us far away from our big

love, the sea so we dedicate this post to her, as always.

Calyx nicaeensis is not always

heart shaped, but this lucky encounter took place in Pilio.

Unfortunately, the populations of this sponge have suffered from

a disease outbreak in many parts of the Mediterranean, so it can be considered

rare in a few places, however their populations have not yet been evaluated.

The disease has affected Greece as well.

Old fishermen also used a small part of this sponge to defog their masks.

Sponges are a very important storehouse for biochemical compounds,

with marked medicinal properties and the research has only just begun!!!!

Thorny outside, soft inside!

Dear friends of Medi sea, it is my honour today to introduce to you the Mediterranean's true oyster, Spondylus gaederopus, or as the species name suggests - donkeyfoot (gaederopus).
The thorny oyster can become quite large (15cm height) and is mostly always attached on vertical rocks, however I have found one specimen in the sand,attached on a pebble! and the first photograph is a specimen photographed on a very old bivalve shell Pinna nobilis.
This magnificent shell, is mostly found covered by a red sponge (Crambe crambe)and other organisms, so it is well camouflaged for the untrained eye.
The key characteristic of these shells is that their two valves are hinged together by a ball and a socket type hinge, instead of a tooth hinge as is more common in other bivalves. they range from 1 to 50 m depth and can be found out until the Cape Verde Islands.

The photograph above displays a dead oyster, where the sponge has spread inside and outside the valves!
These shells are very good to eat raw, they are treated as a delicacy, and thus their other common name in Greece, the Royal Oyster! However, let me remind you that this shell is a filter feeder, meaning it sieves everything that is in the water,
so, in neolithic Europe, when these were often used for bangles and ornaments, and food as long as 5000 years ago, the seas where pure, crystal clean!No technological revolution, meant anything you ate was safe, nowadays the sea can be a dangerous source of toxins, so keep that in mind before munching on too many.. (Shells of this species have been found in Kastoria-Dispilio (mainland Greece) inside the remnants of the lake city!)

Also, special care must be taken when consuming this oyster in restaurants, if you don't know what a fresh oyster looks like, don't consume, they can be dangerous.

Funky slug making lurve circles...

The Eastern side of the Mediterranean, never seems to stop suprising us with its beauty!
Phyllidia flava is the only representative of the Phylidias, in the Med,
and here we have two specimens (yellow blob) on the two orange shponges, after they have layed their, not so perfect as usual, egg mases.
Phyllidias do not have radular teeth so these slugs eat the sponge by exuding enzymes and sucking the animal off the sceleton.
This photo was taken at 35 meters in Pilio.

A sponge that eats rocks?

Chemical warfare is the most brutal and can be used by very fragile species in the sea in order to defeat the strongest!
This boring yellow sponge uses a chemical acid by product from its respiration to make holes in soft limestone rock, to undercut and surround tiny pieces of rock, which are then spat out with the water flow. In many instances, most of the sponge is hidden in a network of passages and chambers that it has excavated in the substrate, which can be rock or shells. In some instances it can be visible outside the rock in very obvious masses.
This particular specimen is surrounded by a colony of black bryozoa, Reptadeonella violacea .
I have seen the sponge in red as well, but am not sure if it is the same species.

Find the nudi

In two meters of water in Pilion, there is a great abundance of Aplysina aerophoba sponges, and most of them are big and beautiful, except some that have been eaten to bits.....by this beautiful little slug called Tylodina perversa.
You can see on the picture of the sponge the places that have not been munched, and the others that have a duller appearance. The marks that the slug leaves are very big, however the sponge heals easily.
This specimen was a loyal highlight to all divers there, until one day I pass by and look on every sponge but he was not there, the only thing left was its cap..Eaten but never forgotten!

Coral worm castle

This little perch has a very impressive castle, made of a rich yellow sponge Aplysina aerophoba and a very fragile colony of coral worms Salmacina dysteri. The coral worms are only tiny but the colonies can reach up to 15 cm in sheltered areas, without nets or clumsy fin strokes.
Don't disturb the dreams and the castles, glide smoothly!
The photos where taken in Pilion, 5m.

a Pendulum count the time for resurrection?

I lived almost three years by the sea of the southern part of North Euboic gulf. Although Euboic may means something like “nice living” for a snorkeler is not a good “nice living” area. Probably polluted as no other place n Greece the area is adrift of the careless citizens for environmental matters that live there. Some species had succeeded to survive and reproduce in these hazardous waters. Like this sponge (probably Chondrosia reniformis) by hanging reminds me the time that passes. Counting in that the picture takes beyond one of the most popular places of the area (politika lighthouse) makes a big symbolic icon to me. I hope and to you.