1. DIVERSITY IN FISH FAUNA OF TURKISH SEAS
Animelia
Chordata
Vertabrata
Gnathostomata
Pisces
Actinopteri
Perciformes
Ophidiiformes
Mugiliformes
Atheriniformes
Scorpaeniformes
Pleuronectiformes
Tetraodontiformes
Gobiesociformes
Lophiiformes
Notacanthiformes
Gonorhynchiformes
Beloniformes
Acipenseriformes 
Clupeiformes
Stomiformes
Salmoniformes
Osmeriformes 
Aulopiformes
Myctophiformes
Anguilliformes
Cyprinodontiformes
Syngnathiformes
Gasterosteiformes
Gadiformes
Lampriformes
Beryciformes
Zeiformes
Hexanchiformes
Carcharhiniformes 
Lamniformes 
Squaliformes
Torpediniformes
Squantiniformes
Rajiformes
Chimaeriformes
Elasmobranchii
Holocephali
DIVERSITY IN FISH FAUNA OF TURKISH SEAS
Elizabeth Grace Tunka ERONAT*1 and K. Can BIZSEL2
1Faculty of Fisheries, Ege University, P. O. Box Izmir, TURKEY
2Dokuz Eylül University, Institute of Marine Sciences and Technology,
DEVOTES-EUROMARINE Summer School 9th to 11th June Aquarium of Donostia- San Sebastián (Spain)
Turkey, as an intersectional area among different habitats and climatological properties due to its geographical position, has a wide range of biodiversity with respect to animal and plants species. This is not only restricted with the terrestrial ecosystem but also the aquatic ecosystems, and this is particularly apparent for the marine ecosystems which show great biodiversity with varying physical properties such as lower salinity (‰ 16-18; brackish waters) and temperature (4-25 oC) also with limited livable demersal area in the eutrophic Black Sea and higher salinity (‰ ; highly saline marine waters) and temperature (13-28 oC) with unlimited demersal area in the oligotrophic Levantine Sea. Another important fact is that being close to the Suez Channel, which is one of the main pathway for non-indigenous species introductions to the habitats in Mediterranean marine ecosystems. New species can adapt easily to these diverse habitats as a result of the removal of salinity barrier of Nile River by Aswan Dam. The focus of study is to compile a checklist of species diversity in fish fauna of Turkish waters. These waters are divided into 4 seas; in the north Black Sea, in the north-west Sea of the Marmara, to the west Aegean Sea and in the south the Levantine Sea.
An up-to-date checklist of the fish fauna was compiled from records and previous studies dating back to 1970s. As a result, 169 (30 %) species from Black Sea, 257 (46 %) species from Sea of Marmara, 438 (79 %) species from Aegean Sea and 458 (82 %) species from Levantine Sea in total 555 fish species were listed belonging to 346 Genus, 155 Family, 35 Order and 3 Classis. This list is composed of 489 (88 %) bony and 66 (12 %) cartilaginous fish species, where the cartilaginous fishes represent 75 % of cartilaginous fauna of the Mediterranean. The distribution of number of these species by seas is given in Table 1. Table 2 provides information on the distributions of different taxon levels (order, family and species) per main habitat categories which are Brackish, Marine & Brackish and Marine. Same table also provides additional information on the number of species per habitat per seas. IUCN statuses of these species are given in Table 3. Finally, the number of families, genus and species with lessepsian and endemic species for each order are listed in Table 4. The contribution of lessepsian migrants to the non-indigenous species are 66 fish species which corresponds 12% of total fauna.
Similarity analysis was also performed to determine the level similarities among seas on the basis of the species composition by seas and habitat categories (Figure 1-2). In Figure 1a , it was observed that the overall similarity among four seas is approximately 55% while and it improves up to 70% between Black Sea with Sea of Marmara and up to 85% between Aegean Sea and Levantine Sea. When Aegean Sea and the Sea of Marmara is considered, similarity is still at the level of 70%, however, the similarity levels of Sea of Marmara-Levantine Sea and Black Sea-Levantine Sea have substantially declined down to levels around 40%. Together with the results of MDS analysis (Figure 1a-b), it is apparent that that Black Sea has its own fauna while the fauna of Levantine Sea has gradually changed towards to Black Sea throughout the path along Aegean Sea and Sea of Marmara, due mainly to the interactions between Black Sea and Mediterranean ecosystems. It is also clear that the similarities between seas are dominated or determined by some species that inhabit specific habitats, such as the similarity percentage between Black Sea and Sea of Marmara is determined mainly by species that can inhabit brackish waters but also marine and brackish waters. The similarity between Sea of Marmara and Aegean Sea is determined by species that can inhabit marine and brackish water. Also the
similarity between Aegean Sea and Levantine Sea is determined by species that can inhabit marine and brackish water but also species that inhabit only marine waters (Figure 2a-b; Table 1).
In conclusion, the ecological and climatological condition of Turkish waters varying from subtropical to temperate make possible the diversification in habitats and thus in fish fauna of these waters. A continuous process of one-way migration of non-indigenous fishes from Suez channel towards Levantine Sea, i.e.; the southern coasts of Turkey, the species diversity of fish fauna will keep increasing.
Table 1. Number of species with percentages per sea and common species amount between seas. * A: Black Sea, B: Sea of Marmara, C: Aegean Sea, D: Levantine Sea
Table 4. List of orders and family, genus and species numbers belonging to the orders that inhabits Turkish seas
Seas*
Bony Fish
Cartilaginous Fish Σ
Bony Fish %
Cartilaginous Fish %
Σ % A 21 4 B 1 2 C 43 3 46 9 5 8 D 78 6 84 16 15
A-B 10
A-C
A-D
B-C
B-D
C-D
124
145 25 32 26
A-B-C
A-B-D
A-C-D
B-C-D 74
100 39 18
A-B-C-D
121
130 14 23
489 66
555
Order
Family
Genus
Species
Lessepsian
Endemic
Acipenseriformes  1 2 6
Clupeiformes 3 11 19 5
Stomiiformes  4 8 10
Salmoniformes 
Osmeriformes 
Aulopiformes  9
Myctophiformes 17
Anguilliformes 
Beloniformes  7
Cyprinodontiformes 
Syngnathiformes 14
Gasterosteiformes 
Gadiformes 16 23
Lampriformes
Beryciformes 
Zeiformes
Perciformes 53
143
249 35 33
Ophidiiformes 
Mugiliformes
Atheriniformes 
Scorpaeniformes 22
Pleuronectiformes 29
Tetraodontiformes  13
Gobiesociformes 
Lophiiformes
Notacanthiformes
Gonorhynchiformes 
Hexanchiformes
Carcharhiniformes  15
Lamniformes 
Squaliformes 
Torpediniformes
Rajiformes 27
Squantiniformes
Chimaeriformes
TOTAL
155
346
555 66 45
Figure 1a-b. Cluster (A) and MDS (B) analysis of similarity of the seas according to species distribution A B
Table 2. Number of fishes by order, family, species and by seas per habitat.
HABITATS
Brackish
Marine
Marine and Brackish
Total
Order 2 28 23 53
Family 3
129 62
194
Species 6
392
157
555
Black Sea 74 90
170
Sea of Marmara 1
166 92
259
Aegean Sea
327
112
439
Levantine Sea
333
126
459
Figure 2a-b. MDS analysis of the seas factor as species distribution on the left (A) and habitats on the right (B). (A: Black Sea, circled orange; B: Sea of Marmara, circled yellow; C: Aegean Sea, circled grey; D: Levantine Sea, circled blue) A B
Table 3. IUCN statuses of species inhabiting Turkish waters
IUCN STATUS
Bony Fish
Cartilaginous Fish Σ
Critically Endangered 7 4 11
Data Deficient 63 15 78
Endangered 2 6
Least Concern
254 10
264
Not Threatened 9 14 23
Vulnerable 18 25
References
Please contact with the corresponding author.