aegean SECTION 4

Our Southern Aegean Sea Marine Life Database
is in five sections:

MAMMALS

The sighting of mammals underwater in the central and southern Aegean and Mediterranean coasts of Turkey is very rare. Less rare are sightings of Dolphins and Turtles on the surface which are often seen from diveboats' travelling between dive sites.

DOLPHINS

The distribution of Dolphins in the Mediterranean and Aegean Seas is governed largely, if not exclusively, by the availability of food. In global terms the waters of the Mediterranean are relatively unfertile and do not produce the food quantities required to sustain large groups of dolphins. This makes their appearance around the Turkish diving areas rare and then often only small social groups of between five and ten animals are seen. There are marginally more sightings along the southern, Mediterranean Coast of Turkey.

SEALS

Seals are very rare around these coasts although there have been a few reported sightings. Individuals encountered have been extremely shy.

TURTLES

The south western region of Turkey is an important area for the loggerhead turtle which returns each year to breed in the area around Dalyan. Dalyan is at the southernmost point of the Aegean coastline of Turkey and the beaches provide the perfect place for the turtles to lay their eggs.

MOLLUSCA

Mollusca have chalky shells, except octopus and sea slugs, a wide range of color and shell pattern, often a yellow fleshy body and no obvious body segments. Species include Octopus, Snails, Sea Slugs, (Nudibranchs) and Bivalves.

SNAILS and SLUGS (Class: Gastropoda)

Snails and slugs have internal gills and although present, the shell is usually reduced and often enclosed by the mantle.

SEA HARE (Aplysia depilans)

The sea hare is a gastropod and normally lives among weeds in shallow water. They can often be seen swimming with what appear to be wings. They have four head tentacles, the rear pair are large and resemble the ears of a hare. When mature they reach 25cm long and brown green in color, sometimes with white spots, younger specimens are a reddish brown color. If threatened they sometimes eject a harmless purple dye.

TRITON (Charonia nodifera)

This mollusc is a carnivorous predator preying on starfish and other slow moving animals. They have a large cone shaped spiral shell up to 20cms in length colored brown yellow orange, matching to some extent their habitat among rocks and weed over which they are fairly mobile. They have two very distinctive retractable pointed black and yellow banded head antennae branching out in front of their eyes

MEDITERRANEAN CONE SHELL (Conus Mediterraneus)

This species of a familiar mollusc can be found in shallow sandy bays in great numbers during July and August. It has a short siphonal canal and a long slit like opening with a straight, sharp outer edge. They have a single sharp, venomous hollow tooth which they flick out to inject their prey or in defense if they are threatened. If mishandled by divers the venom can cause varying levels of pain. Fortunately the Mediterranean species are not as poisonous as their tropical relatives.

COWRIE SHELLS

There are many species of cowries of varying sizes and colors. Their most distinctive feature is the long slit like opening running from end to end and a very smooth outer surface. In life the animal extends a thin mantle over the exterior of their shell and this is the reason why these shells are so smooth and have such a slippery feel. If they are disturbed the cowrie quickly withdraw their mantle into their shell, emerging very slowly when no longer threatened.

GIANT TUN SHELL (Dolium galea)

Normally found in deeper water this mollusc often burrows beneath the surface of the sand with only a small part of its round shell visible. They feed on relatively large slow moving organisms like sea cucumbers, which they ingest whole. The disproportionate volume of their prey often makes it impossible for them to retreat into their shell, and is the reason why they seek protection by burrow themselves into the sand. Empty shells, sometimes up to 150cms in diameter, can often be found in less dived areas.

NUDIBRANCHS (Order Nudibranchia)

These often highly colored Opisthobranchs lack a shell, have obvious naked gills and a pair of head tentacles. The gills and tentacles are retracted quickly into the body if they are disturbed or threatened.

Many small species of nudibranch exist in Turkish waters. Particularly common is a bright violet colored species which can often be seen clinging to seaweed or marine plants with its fragile appendages waving even in the slightest of currents. Another common variety to be found clinging to rocks or to the surface algae is (Peltodoris atromaculata), which has a flat oval light cream colored body with dark brown patches. Generally between 1cm to 4cm in length they can occasionally reach up to 6cms long, there are two unbranched head tentacles and 9 branching gills in a ring on the back.

SPONGES

Sponges are sessile animals whose bodies consist of a single cavity with a major exhalent opening and many smaller inhalant openings. The bodies also contain calcareous or siliceous spicules, or horny fibers, which provide support and exist in almost every color imaginable. There are three classes of sponge, Calcarea, Hexactinellida and Demospongiae, and over 1000 species. Sponges often resemble, and are mistaken for plants. Unlike plants, which rely rely on sunlight for photosynthesis, sponges inhabit both the shallow and deep water regions of the worlds seas and oceans.

The seas around the coast of Turkey were once important sponge producing areas, but the collectible bath sponge, (Spongia officinalis) no longer exists in commercially viable quantities. Many other species of sponge do flourish here and are too numerous to list in this guide. Anyone with a particular interest in finding, identifying and cataloguing the sponges which inhabit Turkish waters will find a wealth of study here.

BLACK SPONGE or DARK GREEN SPONGE

The most common and largest species of sponge in Turkey. It is normally attached to rocks, can be up to 120cm in diameter and often provides a comfortable resting place for the black green groupers.

TUBE SPONGES (Verongia aerophoba)

These bright yellow sponges grow to 40cms in height. It is a fairly common species and can be found both in shallow and deep water, attached to rocks or on sandy and shingle areas.

SURFACE ENCRUSTING SPONGES

Surface encrusting sponges are numerous and can be seen at all depths. They are distinctive, being smooth, often with a slimy feel and many exhalent holes over the surface. There are a wide range of species in Turkish waters in a variety of colors from bright red, green, brown and black.

FLAT WORMS

These thrive on the predominantly rocky terrain around these shores and many examples can be seen on every dive and they are often mistaken for Nudibranchs. Sometimes quite mobile, look out for the small brown species with white irregular spots and two tentacles at the head which they quickly retract if they feel threatened.

BRISTLE WORMS (family: Annelid)

Bristle worms are a very successful species which has been scavenging the bottom of the shallowest seas and deepest oceans of the world for millions of years. Usually to be found hiding under rocks and in crevices during the day they venture out at night in search of carrion. During the mating season, which is during mid summer in Turkey, certain species can be seen during the day standing vertically on rocks either singly or in large writhing groups. They can grow to 15cm in length and they resemble furry caterpillars, the fine poisonous hairs along the body flaring white if disturbed. While they are not dangerous to divers, contact with the skin can result in irritation which can be quite painful and last for several hours.

PEACOCK WORM (Sabella pavonina)

This species of worm belongs to the family Sabellidae, which are tube dwelling polychaetes. This species common in Turkish waters, has flower like gills consisting of between 8 to 45 filaments which fan out at the top of the membranous tube. If disturbed the gills retract quickly into the tube.

SEA SQUIRTS (Class: Ascidiacea)

These solitary or colonial organisms grow attached to rocks and consist of a tube shaped body made a material resembling cellulose. At the top of the body is an inhalant siphon and on the side of the body is an exhalent siphon. Water is pumped through the body where food and oxygen are extracted. There are several species in Turkish waters.

RED SEA SQUIRT (Dendrodoa grossularia)

The red sea squirt is the most common species of sea squirt in Turkish waters, it is soft and smooth and appears to be red brown in color, though on night dives they are bright red by torch light. If disturbed they close their distinctive, four leafed inhalant siphon and contract their body becoming hard. More difficult to find but nonetheless numerous, is a dark brown species resembling encrusted rock, which can be up to 20cms long and usually found hanging under overhanging rocks. If disturbed, the whole organism contracts strongly closing both inhalant and exhalent openings.