black sea red data book - Department of Biology

of balcanica, but has been called ancilla (a name that takes precendence over
balcanica). Along the Turkish Black Sea coast, a form with average wings spots
occurs (C. splendens amasina) as far east as Gorele (not far from Trabzon).
Eastwards, it is replaced by a form with colourless wings (C. splendens waterstoni),
that extends as far as the Coroh (Coruh) valley in Georgia. North of that, and as far as
the Caucasus, it is replaced by narrow-banded C. splendens mingrelica (possibly a
hybrid between several other forms). All these subspecific taxa freely hybridize and
form clines of varying steepness and width. In the coastal rivers of the Crimean
coastal mountains, finally, a very narrow-banded subspecies, C. splendens taurica,
occurs in isolation. The populations of south Russia deserve more study. Of all
subspecies listed, C. s. waterstoni is probably the most restricted in range and hence
the most threatened one.
Habitat type, Critical habitats, Limiting factors. Brooks and rivers rich in
vegetation and slow water velocity, from sea level to c. 1000 m a.s.l. in the
mountains. The main limiting factors are water pollution and the elimination of zones
rich in vegetation as a result of stream realignments.
Biology. Larvae rheophilous, relatively common, inhabitants of rich in vegetation
localities in the rhithral and the potamal; both larvae and adults active predators. Two
year life cycle. Period of emergence V-IX. Adults are relatively slow fliers.
Population trends. Although not measured, a trend towards a declining abundance is
observed in Black Sea coastal brooks and wetlands.
Threats. Polluting and/or drying up of the habitats as a result of urbanization as well
as of uncontrolled livestock-farming activity, both on the coastal plain and in
mountainous regions.
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