ANNALES • Ser. hist. nat. • 11 • 2001 • Suplement - Abstracts
Interdisciplinary Workshop "Pattern and Process in Balkan Biodiversity", Koper, September 25-28 2001
BIVALVE MOLLUSCS FAUNA OF ANCIENT LAKES IN THE CONTEXT OF HISTORICAL BIOGEOGRAPHY 
IN THE BALKAN REGION
Alexei V. KORNIUSHIN
International Solomon University, Kiev, Ukraine
Ancient lakes with their unique plant and animal communities are well known as "hot spots" of biodiversity and ref­
uges for relict faunas. Therefore, investigations of these peculiar habitats are important for biogeographical régionalisa­
tion, the reconstruction of faunal history and understanding the mechanisms of spéciation (Stankovič, 1960). Among 
animal groups, gastropod molluscs are distinguished by the great diversity of endemics in some ancient lakes (Baikal, 
Tanganyika and Ohrid) and the presence of high rank endemic taxa (families/subfamilies in the first two lakes, gen­
era/subgenera in the latter). Bivalve mollusc taxa seem to be more conservative and widespread, but nevertheless fam­
ily Sphaeriidae is represented by endemic species and subspecies in Baikal, Ohrid, Prespa, Biwa, the African Great 
Lakes and Titicaca (see Korniushin et at. (2000) for a review), and a number of endemic Corbicula species are known 
from the ancient lakes of Sulawesi, Indonesia. All endemic lacustrine bivalves belong to widely distributed genera, ex­
cept the unique cemented bivalve from Lake Poso included in a separate genus (family Corbiculidae).
At present, twelve species of bivalves are known from Lake Ohrid and five from Lake Prespa (Dhora & Welter- 
Schultes, 1996; Korniushin, unpubl.). Most of them have broad Palaearctic or European ranges, the recent distribu­
tion of Microcondylaea compressa (Menke, 1830) is basically Mediterranean. Two endemic species (Pisidium ed- 
laueri Kuiper, 1960 from Ohrid and P. maasseni Kuiper, 1987 from Prespa) proved to be close relatives of the 
Holarctic P. nitidum Jenyns, 1832 (Korniushin et al., 1998). Pisidium subtruncatum Malm, 1855 is represented in 
Ohrid by an endemic subspecies. Noteworthy, such species as P. amnicum (Müller, 1774), P. henslowanum (Shep­
pard, 1823), P. moitessierianum Paladilhe, 1866 (all found in Ohrid), as well as P. nitidum Jenyns, 1832 are now 
represented in the Balkans by scarce, isolated populations.
Composition of the bivalve mollusc fauna in Ohrid and Prespa does not contradict the biogeographical concept 
of Stankovič (1960) which suggests the origin of the lake's fauna from the freshwater fauna distributed across Eurasia 
in Tertiary. However, the group P. (Odhneripisidium) apparently having its roots in this ancient fauna is represented 
in Ohrid by only one species - P. tenuilineatum Stelfox, 1918, sporadically distributed in other European countries, 
while P. annandalei sensu Kuiper, 1962 (= P. sogdianum Izzatullaev & Starobogatov, 1986) is restricted in the Bal­
kans to Greece.
The taxonomy of Dreissena in the Balkan region is rather intricate. In particular, the Ohrid form was once de­
scribed as a new species and even included in a separate subgenus (Lvova & Starobogatov, 1982), but modern re­
viewers treat it as a variety of D. polymorpha (Pallas, 1771) (Dhora & Welter-Schultes, 1996). While Ponto-Caspian 
origin of Dreissena is evident, the exact sources for its invasion in the Balkan region need to be clarified by the fur­
ther morphological and molecular studies.
Our study shows no testable relationship between the bivalve faunas of Ohrid and Prespa. Similarity between P. 
subtruncatum recalvum Kuiper, 1960 from Ohrid and the form of the same species living in Prespa (Korniushin et 
al., 2000) can be explained by convergence, since similar characters (high triangular shell and broad hinge plate) 
develop independently in many lacustrine taxa.
Thus, the Balkan lakes are rather peculiar in respect of their bivalves, even if compare them to the older lakes 
with the higher general level of endemism, like Baikal and Tanganyika. However, biogeographic information pro­
vided by these molluscs is limited because of their low diversity and wide distribution. Revision of the extremely di­
verse Ohrid gastropods (71 species) by using exact methods of phylogenetic reconstruction including molecular 
phylogenetics seems to have great potential in this respect.
Key words: Mollusca, bivalves, ancient lakes, spéciation, Ohrid, Prespa
References:
Dhora, Dh. & F. W. Welter-Schultes (1996): List of species and atlas of the non-marine molluscs of Albania. 
Schriften zur Malakozoologie, 9 , 90-197.
Korniushin, A. V., Z. Krstanovski & G. Kostoski (2000): Anatomical evidence of close affinity between endemic spe­
cies of Pisidium (Bivalvia, Sphaeriidae) from some ancient lakes and the widely distributed taxa. Journal of zoologi­
cal systematics and evolutionary research, 38(2), 81-86.
Lvova A. A. & Y. I. Starobogatov (1982): New species of Dreissena (Bivalvia: Dreissenidae) from Lake Ohrid. Zo- 
ologicheskij Zhurnal, 61 (11 ), 1749-1 752.
Stankovič, S. (1960): The Balkan Lake Ohrid and its living world. Monographiae Biologicae, 9. Dr. W. Junk, den Haag.
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