28 Nov 2010

Sandy bottom delights



This time we were looking for sea horses but instead we found rays, many many rays!
The sandy bottom realm sounds quite boring, divers stay well away of it, but the sandy bottom hosts an array of very interesting and beautiful inhabitants. Today we present the skate/ray Raja radula,one of the most common rays of the Mediterranean,with some evidence towards its endemism in the area, as the specimens found off the Atlantic could have been misidentified with other similar species, not very hard to do with these rays.
This ray is completely harmless to humans, it has no thorn, like the sting rays and no electricity like the torpedo rays, however the skin around the tail is quite rough, hence its common name, rough ray.
This fish inhabits shallow water until the depths of 300 meters,and this particular specimen was photographed in Stratoni at the depth of 10 meters.All in all, on a 50 minute dive, we spotted 4 animals laying on the sandy sea bottom.
They prefer to eat any type of bottom animals, making Stratoni a haven of food for them!
They are oviparous, laying oblong egg capsules with stiff pointy horns on the ends (mermaid purses). About 80-154 eggs are laid by an individual in a year. Because of insufficient data on their populations it is listed as Data Deficient on the IUCN Red List.

3 Nov 2010

Triggerfish journeys

Photo by Vasilis Mentogiannis

After all these years of diving, travelling and exploring the seas of the world, this was the year I said with the most certainty that even if I only dive here,in Greece, for the rest of my life and nowhere else, I will be happy and content!
Dive Greece Baby!
The beauty of our sea is not only very well hidden and currently very fragile but also it is very little acknowledged. One example, is a completely exotic animal the Triggerfish, which usually lives in tropical seas. The Grey triggerfish (Γουρονόψαρο η Βαλιστής) is a resident of the East and West Atlantic, all the way down to Argentina with rarer occurrences in the East Mediterranean.

Balistidae is a family containing 40 species but only Balistes carolinensis (synonym Ballistes capriscus)can be found in Greece. As a family, these fish are most extraordinary, with colorful lines and spots, especially in their Indopacific range. Their name, triggerfish, comes from the locking mechanism of their anterior dorsal fin, which is composed of 3 spines that fit inside a groove, while only 2 work as a trigger. When the first, (anterior) spine is locked in place by erection of the short second spine, then it can only be unlocked by depressing the second, “trigger” spine.

Another peculiarity of the triggerfish, is their aggressive behavior against other fish in small aquaria, or divers when they approach a nest of eggs. At this point, it is advisable to swim away from the nest and not over it, as their territory is conical reaching to the surface. If you add the aggressive behavior of these fish, along with their strong, fused teeth, you have one vicious, unnecessary bite! Some strong attacks have been mentioned from bigger, more tropical species, but for the Grey triggerfish this has not been reported.
Balistes carolinensis prefer to eat small crustaceans and mollusks from the benthos. Their skin is very tough and leathery.
It seems that this particular individual is a juvenile, because the tips of its caudal fin are not elongated yet। As an adult it can reach the size of 60cm! Their reproductive season is in the summer, when spawn is placed inside a crater on the sand, and is guarded by the female (male in the tropics), a sure sign you should swim around and not over the nest!
The color of the Grey triggerfish is mostly grey with brilliant fluorescent turquoise dots on upper half of body and median fins, and irregular short lines ventrally. There may also be three faint irregular broad dark bars on body and a narrow pale transverse band on the chin.

This particular beauty was hanging out under the traditional fishing boat (kaiki) Agios Nikolaos, the boat that broke the embargo to Gaza in the summer of 2008 http://www.youtube.com/watch?v=8gRscVeNbDo&feature=related.
The second expedition took place this year with tragic consequences....



The boat was anchored next to the Isle of Modi in the NE Peloponnese, but that is a whole different adventure soon to come on Medi Sea!
Until then, thank you Vasilis for capturing the elusive fish!

28 Oct 2010

the third, the unknown the luckiest.


While swimming at Chorto bay in the Pagasitic gulf, I had the chance to check the marine life that lives associated with the Aplysina aerophoba sponges. I wasn’t alone, as this tiny fish had the same interests with me. It is the third, the smallest and the most unknown common fish species of the genus Serranus in the Eastern Meditteranean Sea.

Scientists of Ichthyology give it the humble name Serranus hepatus. I don’t think that this defame matters the fish, as its famous cousins are famous because fishermen catch them with hooks. It doesn’t feel unhappy of this because it knows that it’s better being an insignificant swimmer, than fried and famous. You can differentiate it from the Serranus cabrilla by the big black spot on its dorsal fin.

More information about our friend can be found in studies made by Abdoulaye Wague (in Greek click here) and Murat Bilecenoglu (in English and Turkish click here) .

24 Oct 2010

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.

18 Oct 2010

More variable more watchers.

Except from having a great variable of color Hypsolodoris picta (as Elina inform us in the previous post) the nudibranch has and a great variable of cousins. The variable of color can reach to reddish coloration that we can meet at Cape Verde and the whitish coloration that we meet at several areas. The subspecies dividing of the species is ambiguous as the distribution of the species doesn’t match with the biologic taxonomy of the subspecies. In the photo above that provided to us by Konstantinos Vatikiotis we can admire an individual of the genus Hypselodoris (probably Hypselodoris villafranca but there is and a possibility to be a juvenile of H.picta). At the photos lower you can see more H.picta coloration and patterns. Have a look along with Frank!
First and second pic above from Santa Maria Paros, the third one is from Emporios bay Chios and the right above is from Kelifos island at Chalkidiki. All this locations are at Aegean sea.

15 Oct 2010

Variable colored beauty of the sea

The sea is full of suprises, we have seen this by now many times, but what never seems to astonish me is the suprises we find when we least expect them. Like yesterday for example, I dove in 4 meters of water in the muddy straight between Galatas and Poros, for training purposes.. I never go in the water without my one and only small camera, just for those suprises...and look what I found!
The beautiful Hypselodoris picta


This chromodorid is the largest of all chromodorids in the Mediterranean, reaching a size of 20 cm and it's distribution reaches as far as the Eastern Atlantic.
Because of its chromatic variations, this species has changed many names with the most common synonym being Hypselodoris elegans.
Nowdays, it has at least 5 subspecies depending on its locality and color.
This magnificent slug prefers to eat various sponges but its favorite food are sponges of the genus Dysidea.

8 Oct 2010

Pompanos as companions




This summer, never was I lonely on the shallow dives. The minute I jumped in the water 3 beautiful Pompanos(Trachinotus ovatus, Litsa, Mavrolitsa or Gofari in Greek) appeared immediately and were our loyal followers throughout the dive. They swim very fast, in a most elegant fashion and their curiosity is high, coming very close to swimmers without fear.
Their tail is fork shaped as is typical of the carangids, with a black spot on the tip of the caudal, dorsal and anal fins. They also have 3 - 5 dark spots on the front end of their body. The biggest specimen recorded was measured at 70 cm, although most commonly at 35 cm. Its distribution has been recorded from the Eastern Atlantic, Bay of Biscay, British and Scandinavian waters (rare) to Angola, including the Mediterranean Sea and offshore islands.
They usually swim in small schools near the coast in shallow waters, over sandy or muddy bottoms, unlike their other relatives of the amazing family Carangidae, which are mostly pelagic. They mostly prefer to eat small crustaceans, mollusks and fishes.
For this reason they are easy to spot and photograph.
Pompanos have a high salinity tolerance and are in the process of being farmed in China although they have a low food conversion rate, with trials being made to grow them using soyabean and fishmeal.

9 Sept 2010

Strangers with the strangest eyes.

In an older post we talked about C.Mediterraneus and how lonely it feels in our seas, because none of the 400 members of its family live in our neighborhood. In our fantasy, we can imagine that a similar (it actually only looks similar) species heard its sad story and visited him to live in the neighborhood with big opportunities for the marine animals. It is called Strombus persicus and comes at Medisea from the east as an immigrant. It is also the only member of its family in the region (a second species may have beem possibly established, the Strombus mutabilis).

Strombus sp. are strange gastropods with big human-like eyes. When you see it you think that you are looking at something different than a snail. Maybe a cursed mermaid, who knows? Except from its strange eyes it has an unexpected way of moving. Its operculum is sickle-shaped and hooks to the bottom helping the snail to move. The movement looks like little jumps and it’s very different from the sliding movement of the other snails. For its bad luck it is not able to dig with the strange operculum. If it digs it can find fossils of a famous big snail that lived at the Mediterranean Sea before thousands of years called Strombus bubonius.
Info about the superfamily Stromboidea you can find on this site!!!

Strombus bubonius; Tyrrhen, 97.000 years old, Pleistocene; San Juan de los Terreros, Almeria, Spain; 82 mm; Coll. Aart Dekkers STR9063
Photo contributed by www.stromboidea.de and Mr.Aart Dekkers

7 Sept 2010

Volcanoes, roses and a prince.


On little Santa Maria beach,Paros, if you swim at the depth of 4-5 meters and deeper, on the sandy parts you may notice a lot of small hills with a hole in the top. These “volcanoes” are nests of marine animals. Bivalves or worms are the most possible inhabitants of the volcanoes but until now I didn’t have the chance to check it. When the volcano is dirty,it has the same behavior with all the volcanoes. It explodes and you can notice small stones throwing away from the hole.
Of course, and as in every lonely planet, except from the volcanoes you can also see roses. The roses of the area are alive and have a worm inside them. They are spiral tube worms but for we will talk more about them in future posts. So the volcano is dirty and the rose alone? Of course not! Our planet has its capricious prince, the little weever. It is capricious because if you annoy him it will give you his poison. (stop the pain by putting the injured area in hot water 44C to 49C). It spends its day by laying over the volcano and negotiating the terms of volcano cleanliness with the worm, trying to help the rose with the existential thoughts. That's how our friends spend their day on the sandy beach.

When the roses ideas make our hero tired, he prefers to bury himself instead of going away.

The volcano is such a good place for scanning around and resting.

The hard thing is to convince the worm to let you clean the volcano.

Casting: The little prince : Trachinus draco
The rose : Sabella spallazanii ???
The volcanoes : species from phylums Annelida or Mollusca.

Check the history and the wreck-story of the original inspired author at wikipedia

4 Sept 2010

Close Encounters of the Third Kind


When I went to Athens on late of June, I met my father who showed me some pics of the strange fish that live under his boat. It was a pic from the anchoring rope of the boat where you could see three shadows standing by the side of the rope. Exactly in the same place (in the same rope) and before 2 years I had first met the Cornetfishes that live at Mediterranean sea. I met them as we were coming back from a dive with Elina, and as we were getting out of the boat I spotted the same shadows from my fathers pics. Fast and cautiously (because it was illegal to dive there as there where running construction works) I slid into water for two minutes to take these pictures. In the pics you can see one of the small cornetfish from that contact. It has a very strange tail with a membrane being in the place of the whiplash that usually exists at the end of the cornetfish tail.
My last contact with the invading alien "ehmm sorry fish" ,was before one week during a wonderful night dive. I spoted a big fat cornetfish (I think it was bigger than 1 meter) by some Poseidonia plants, at the depth of 15m. I don’t know why the fish was extremely friendly towards us. Maybe it was tempted by our wonderful character, but I mostly believe that our powerful lights helped also. It changed its color (when it was alone it was striped) to a bright green-blue and started moving between us and hitting our masks with its mouth! I petted it and took some nice pics before we let it continue to its hunting for little gobies and other small fishes. I have to remind you that the Fistularia commersionii is one of the species that invaded the Mediterranean sea through the Suez channel. In the picture you can see Linda petting the fish. Linda has her birthday today and she draws fishes while she is studying biology and diving. So Happy birthday buddy and hope you soon reach thousands of dives and have close encounters with all the lovely marine animals.

31 Aug 2010

Summer's almost gone but the celebrations continue.



Tomorrow is the beginning of autumn and as every time autumn begins, the summer goes away. As every time the summer goes away, we have to listen to the same song of the Doors .
Ok that’s enough with the matters outside the sea. When the autumn begins, all the virgos of the zodiac cycle celebrate. Unfortunately none of the animals of the eastern Mediterranean is virgin so we don’t have anything to celebrate. No? Of course not! If you look deep in the arthropods' classification, you can find a forgotten family of tremendous crabs called Parthenopidae. Parthenos is the Greek word for the virgin so in honor of this today we will introduce one of the most unknown families of the crabs of Mediterranean Sea. I have met crabs of this family 3 times and I think that all of them belong to the same species but yet I am yet unsure which species it is. I cannot find enough information about this family and this may be, because, these crabs don’t like the lights of publicity.
They prefer spending their time burried in the sand. That’s a pity for the naturalists as they cannot admire their impressive claws and their beautiful purple. The common name for these crabs is elbow crabs to fame their giant chelipeds . Maybe, if you compare them with the body size they are one of the biggest claws in the nature.
According to the Greek mythology, Parthenope was one of the sirens that were trying to seduce Odysseus with her song. Odysseus escapes from the trap and from her despair the siren falls into the sea and dies. The body of the siren washed ashore on a beach in the south of Italia and some travelers from Chalkidians that had just arrived found her. They burried her, and started to make their city around the grave. They gave the city the name Neapolis and this city is the famous untill our days as Naples. Annibale de Gasparis a scientist of astronomy, many centuries later named 11 Parthenope a small planet that he discovered as he was working in Naples.
Summer’s almost gone.

23 Aug 2010

Trapped by love!


One of the most colorful fish of the Eastern Med, the Ornate wrasse reminds me of a busy butterfly flying from flower to flower. It swims very fast using only its pectoral fins, a characteristic of the Wrasse family (Giloi, xeiloudes). Thalassoma pavo displays hermaphroditic protogyny, which means that it is born a female and later on in life it transforms into a completely different, more vibrantly colored male. These wrasses are thermophylic (prefering warm water) inhabiting rocky, coastal areas. Their density increases along with temperature, and due to the recent sea temperature rise, their distribution is spreading northwards towards the Adriatic and Ligurian Sea.
Their Greek common names are Gaitanouri, Galani or simply Gilos.
Favorite food includes small crabs and shells.
Recently, I came upon an impressive lonely male and a different population of many females and their males in a very impressive gathering/harem.
The males can reach 25 cm in length and cannot be mistaken with their beautiful lunar tail and exotic blue/pink painted face ,yellow/green body and one single blue band going down after the gills. The females are smaller with blue bands and a black spot under their dorsal fin in the middle of the body.


above- a male T.pavo pose at our camera

above- a female T.pavo exploring two divers

above- the juveniles also have a different coloration

15 Jul 2010

The magnificent 7


Some songs stuck in your mind at such a point that you easily remember them even if your see a number that is at their title.
Scuba diving in shallow water is one of my favorite habits. There so much light there (guys we are still in Greece) that you don’t need to use strobes to make nice pictures. Also you can see all these schools of juveniles making their first walks around the sea grasses. Small sea breams, wrasses and goatfishes are everywhere and as you have a friend with long patience or the same tastes, you can enjoy a lot scuba diving at 4 or 5 meter. Also it is a good way to be more familiar with our equipment as it harder to control your buoyancy. These schools of young goatfishes make to us excellent company at a June dive as it drove us to all the young wrasses of the area.

9 Jul 2010

Now you see me, now you don't! Lessons in camouflage

The sea is a unique ecosystem hiding many suprises. You may be passing over a 2 kilo octopus or a 1m fish and not see it unless your eye is trained to make out their unique shapes from the exact same color background.
Camouflage is employed by fish, cephalopods, shells and other animals, in an attempt to protect themselves from enemies or carnivores that want to eat them.
For example, at two meters of water in front of a busy swimming area, swimmers have no idea that below them lie hiding two masters of camouflage, a juvenile Sepia officinalis and one of the few species of Scorpionfish that live in the Mediterranean.



Did you spot the cuttlefish (soupia)?

check out a new small video of the same animal playing with another baby cuttlefish just before the middle of the clip
on our you tube channel


This scorpionfish, Scorpaena porcus as the name suggests, has a potent poison on its spines, causing the biggest and strongest men or women to cry like babies for approximately three days, if they are unlucky enough to accidentally tread on one.
It is in no way aggressive and relies purely on its camouflage to get its' food, by sitting as in meditation, completely still
waiting for an unlucky fish or crabs to swim by and then opening its gills slightly, creating suction.
The poison is used purely for protection, for bigger enemies. Scorpionfish are quite hard to identify, but we know this one is Scorpaena porcus because the tentacles over its eye are longer than it is wide, and it lacks the bottom chin appendages!

18 Jun 2010

Red Soldierfish, the guardian of ancient amphoras




Sargocentron rubrum, has been established in the Mediterranean Sea since at least 2002, as recorded by the CIESM Atlas of Exotic Fishes in the Mediterranean Sea.

The Red Coat Soldierfish arrived via the Suez Canal, becoming a very common fish in the southeastern but also southwestern Mediterranean, and is the only species of the family Holocentridae that has moved to our seas until now.
This specimen was photographed off the South Coast of Cyprus, over a 4th century BC wreck, which was carrying the most precious wine of the time, from Chios.
The archaeological excavation of the wreck was conducted by the University of Cyprus, in collaboration with the Department of Antiquities of Cyprus and the THETIS Foundation.
This photo was taken at a depth of 45 meters during the expedition in May 2010.
In Greece its distribution is in the most southeastern parts, like in Kastelorizo, where the population is very active.
A survey conducted on an artificial reef of the coast of Israel found its biomass to have increased from 64% in 1985 to 95% in 1995 (E Spanier, Changes in the Icthyofauna of an Artificial Reef in the southeastern Mediterranean in one Decade, Scientia marina, 64 (3) 279-284). The author speculates that this dramatic increase in Israel and other neighboring sites, is either due to the competitive exclusion of autochthonous species by Lessepsian migrants, taking over spatial and food resources, or another possible explanation could be the over-fishing of the targeted, commercially important, groupers and sparids.
The wreck of Mazotos, off the coast of Cyprus, is definitely acting as an artificial reef amongst the vast sandy plains of the sea bottom, but, thankfully, due to its protection as an archaeological site, it is not fished very often, with the exception of rogue fishermen/looters
This beautiful fish cannot be mixed up with any other in the South Mediterranean, well until any more decide to change oceans! Its skin is very rough with hard scales, and the spine on its cheek is venomous, so look, but never touch
It is usually found in coastal reefs, wrecks, caves or cracks of rocks and very often occurs in aggregations.
They feast on benthic crabs and shrimps but even small fishes

3 Jun 2010

I'm sticking with you



Limpets are gastropod shells but they do not have the typical gastropod shell shape, as can be seen in the picture. The common hey hole limpet can reach 40 mm long and can be found in the Mediterranean sea, but no longer in the North Sea, any specimens in the south eastern part of the North sea that are washed out are thought to be fossils. When viewed from above, Diodora graeca, is oval shaped with radiating ribs and bold growth lines. The color varies from creamy to yellow white often with brown, radiating rays. The hole on the top of the shell serves as an outlet for water and waste products. It can be found in deep water up to 200 meters, but this specimen was photographed in Platanitsi at a depth of 10 m. Just like other limpets it adheres firmly on the sides of rocks, making it very hard to detach, unless you use a knife...but why would you do that to such a beautiful, docile creature. This family is mostly herbivorous but the key hole limpet likes to feed on certain species of sponge, especially Halichondria and Hymeniacidon.
And as the Velvet Underground song goes.....I'm sticking with you....coz' I'm made out of glue!

31 May 2010

Some days you cannot take care of what you love.



Our souls are there.

www.shiptogaza.gr
http://news.bbc.co.uk/2/hi/middle_east/10195838.stm

20 May 2010

Colonies and immigrants




Didemnum sp. colonies can been found from the very shallow water up to the depth of 15 meters. These are the colonies of the tiny ascidia which love the light (photophile). There are thousands of them in every colony that you meet. A colony can be found over seaweeds, inside the P.oceanica or on rocks. I have met them in both very polluted water and in very clean. It’s hard to identify the species by the photographs but these photos seem to be of the Didemnum commune. The increase of the sea temperature seems to have given new opportunities to Didemnum sp. to emigrate to new places of the endless sea. So, as we nicknamed ascidia in previous posts, these long cousins have a similar behavior with us. They make big cities and then they leave them behind to find new worlds for development.

27 Apr 2010

A goby in the muck


So, it has been a couple of months I haven't visited Kalogria in Chalkidiki, and luckily Hector visited me so we went!
It was wonderful to be in the water again, but unfortunately the sight we saw was not a very pretty one. Ok the sea bed was covered by the seasonal weeds but the shock was that of very sick sponges ... that were covered by a white slime, that looked like it was suffocating the sponges, causing them to melt....we are looking into what is causing this and will keep you posted. In between the slime, a lonely Thorogobius ephippiatus looked kinda confused....
The leopard spotted goby is one of the easiest gobies to identify because of his pale fawn body and distinctive dark purple or black spots. It has a relatively large body, reaching a maximum length of 13 cm, and the breading males are darker in colour with a conspicuous light-pale blue edge to the dorsal and anal fins. These gobies love to eat amphipod crustaceans and worms.
Most often you will find them in ledges and crevices in vertical rock faces down to a depth of 40m. This fish was photographed at 25 meters.

11 Apr 2010

Looks like a ghost but it is a long cousin!

Tunicates or sea-squirts or ascidians is common names that we use for the members of the class Ascidia (or class Ascidiacea). This class belongs to the phylum Chordata which is the phylum that belongs and “our” class Mammalia.
Cione roulei, Lahille, 1887 is also known as red tunicate. It seemed very strange to me when I first see it at Paros. I don’t think that it is common to find this animal at the eastern Mediterranean. It is strange and I didn’t understand that it is a tunicate at first sight. It has an inner and outer part of the animal. The outer part looks like a cloak or a ghosts sheet. If you touch it the inner red part will move while the outer not. I find them at less than 5 meters depth and this animal prefer living at deeper. After I found the impressive couple of the first photo I continue swimming around to find more of them. I found one without obvious ghost sheet and one without color inside. I think that all this are C.roulei but I cannot be sure because I left them there. In next posts we will learn more about tunicate biology and meet more members of that class.



12 Mar 2010

Tiny creature with brilliant color



Take a look inside the shadowy hole. Something strange seems to be there. It's bad luck that my curiosity disturbs its peace,but I cannot let this chance for a better look at this strange color, go by. Luckily it’s stuck on a stone which can be moved. I really don’t like to disturb the creatures I meet and I rarely do, unless it is something really unique and I cannot take a photo otherwise. It is a tiny limpet and it has a color that I have never seen before on a limpet. Its size is not bigger than 3mm and it was very hard to take this picture with a compact camera that I found on a nearby diver’s hand (thank you Hildegard)!!! I asked Spanish collaborator of www.sealifebase.org Victor Simon if he knows which species it is and he thought that it is a Leptea fulva but he cannot be sure. The shape and the color indicate to this but L.fulva it usually lives deep. Limpets are members of the Superfamily Patellacea of the Order Archaeogastropoda which are the first Gastropoda in the evolution (Archaeo is from a greek word which means ancient).

3 Mar 2010

Snail attack!


On the previous post we saw a tiny, lonely Bittium shell balancing over the huge Pina shell!
Very impressive site caught on camera. This picture shows a mass of Bittium shells muching on the seagrass Zostera marina. These masses are more oftenly encountered in the summer months and less likely in the colder months. If you are swimming by quickly it looks like the seaweed is dirty, but look a little closer and you will see so many tiny little shells, of all colors!
It is a pity the photo was not very clear, but it is very hard for me to focus on something so small with seaweed everywhere. By the end of this summer season expect to find a big variety of miniscule shells that live in the Greek waters. I have collected their dead shells all my life, now is the time for the live animals...stay tuned!

26 Feb 2010

Walking on cliff’s edge?


This tiny gastropod is one of the smallest shells that we can observe in our sea. I think it’s much easier to spot it if it chooses to go for a walk over the Mediterranean's biggest shell Pina nobilis! In this photo, given to us by our friend Sokratis Karalis, the small shell looks like walking between a cliff and a river (it’s a Greek expression don’t blame me if you didn’t understand). I am very happy when I find nice pictures from Mediterranean not so fancy animals. It is very hard to tell which of the Bittium sp. it is but most often we meet at the depths the Bittium latreillii (Payraudeau, 1826).
Sometimes I have detected Bittium sp. between urchin spines so I think these tiny animals are nature’s admirers like all of us.

14 Feb 2010

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!!!!



25 Jan 2010

My one and only

2010 has been declared as the year of Biodiversity by the UN.
Hopefully this will actually mean something more than just a "fancy name " for this year.
Marine Biodiversity in the tropics is immense due to the thousands species of coral and
all the animals that are associated with them, that is well known. Here in snowy Greece
(and the rest of the Mediterranean) we have the one and only scleractinian coral that can
form reefs, Cladocora caespitosa.
We might only have one reef building species of coral here, but our seas are as spectacular
as the tropics, only sized down a little bit, but that does not matter! (Dive Greece Baby!)


Cladocora caespitosa

This amazing coral can form colonies up to 1m in diameter and one big colony was discovered
some years ago on a reef in Vourvourou, Chalkidiki(hope it's still there!)! As most corals, it is
composed of an external, calcareous skeleton which is secreted by the living organism contained
within it. The individual coral polyps(the little tentacles that are visible in the picture above) are
symbiotic with algal zooxanthellae, which photosynthesize to produce nutrients for its host.
The Cladocora coral reproduces sexually, releasing orange eggs and bundles of sperm before the
full moon in the summer months, in the Adriatic banks of this coral this happened in June.
The shape of the colonies depend on depth, light and currents.
It has a growth rate of a few mm per year, making it extremely slow growing.

Diving in Pilion last summer we were shocked to find massive coral structures completely
torn to bits at a depth of 40 meters.


The first time I encountered these massive formations and they were all dead....
Vizualising these corals when they were alive and the life they contained within and around them
is wondrous, but for the sake of biodiversity and for a healthy ecosystem...
I hope this year we permit our one and only reef building coral to grow.

12 Jan 2010

Smooth Callista


One of the most popular bivalves of the Mediterranean sea is Callista chione. This shell is a small scale fisheries target because of its nice flavor. Also octopus and gastropods admire its flavor as you can see on an older post (10/11/2009). After being eaten the shell usually becomes an ornament for flowerpots, walls and lamps. You may know from trees and fishes that the period of time that the animal or plant has slow growth rate is printed on the body of the fish or the trunk of the tree. Something similar happens with those dark thin stripes on the valves of the C.chione shell. Also the slow growth period is from July to October in reverse with trees and fishes that this period is usually the winter. The reproduction cycle starts after the second year and lasts for about one year! Also an adult can live up to 17 year. The species of the photograph should be about 4 years old and has unburied itself, because it usually lives inside the sand. In Greece we call this shell ‘gialisteri’ ( Γυαλιστερή) and this means shiny one.

Sources:
- Population dynamics of the venerid bivalve Callista chione (L.) in a coastal area of the eastern Mediterranean (Angelina Metaxatos 2004)
- Shell growth in Tivela stultorum (Mawe, 1823) and Callista chione (Linnaeus, 1758) (Bivalvia): annual periodicity, latitudinal differences, and diminution with age (Clarence A. Hall, Jr., Wayne A. Dollase and Charles E. Corbató at 1973)

6 Jan 2010

the hermitcloak or anemocrab?




In an older post we talked about the association of Dardanus sp. with the anemone C.parasitica. Now I will describe to you the most admirable symbiosis relationship of the Mediterranean, between crabs and anthozoa. Pagurus prideaux is a hermit crab that can grow up to 6cm and lives usually on the sandy parts of cave entrances. Unlike their great population in the Norwegian coast of the Mediterranean you cannot meet them too often here. When they are young they start to have a symbiotic relationship with the Adamsia carciniopados anemone. Because P.prideaux doesn’t feel very comfortable inside the gastropod shell, they prefer to live with “something like a shell” which the anemone helps to build. That way it doesn’t need to change its shell throughout his lifetime, as the shell grows bigger, along with the crab and the anemone. The anemone covers all the sensitive parts of the crab and the tiny shell like a cloak. The anemone is responsible for her buddies defence. For that purpose when they are in danger the anemone produces a lot of bright pink tentacles with stinging cells. These tentacles are called “acontia” (Second photo “where these animals are frightened the crab runs as the anemone spreads its stinking defence). The most noticeable thing in this relationship is the feeding behaviour. The crab feeds the anemone by putting pieces of food near the anemones mouth! It is possible, even after a few hours, the crab pulls the food out of the anemone’s stomach and eats it.