ITALIAN JOURNAL OF ZOOLOGY, cilt.76, sa.4, ss.403-414, 2009 (SCI-Expanded)
Temporal and spatial changes in abundance, prosome length, oil sac volume, molting patterns and morphometric
parameters were studied in Calanus euxinus from the Black and Marmara Seas. In the south-western part of the Black Sea
and deep shelf zone near Sinop the abundance of C. euxinus was high during the whole studied period (2000–2005), with a
maximum 23,400 ind m22 in March 2004. In the Marmara Sea near the Prince Islands in the deep zone the mean annual
abundance of C. euxinus was 47 times lower than in the deep zone of the Black Sea (during 2000–2007). However, this
parameter reached a significant magnitude of 12,264 ind m22 in spring in Izmit Bay. During the warm season, C. euxinus
are rare in the Marmara Sea. The high temperature and salinity accelerate development in this species; therefore, preadults
and adults possess reduced prosome length and oil sac volume. In the cold period in the Marmara Sea the size and lipid
content in late copepodite stages increase, especially in Izmit Bay. Similar size of eggs, prosome length of early copepodite
stages in the Black and Marmara Seas indicate that the C. euxinus population in the Marmara Sea originates from the
individuals penetrating from the Black Sea through the Bosphorus.