Cladocerans reproduce in two different ways: parthenogenesis and gametogenesis. The explosive increase in their densities is the result of the high reproductive potential in the parthenogenetic generation (Rose et al., 2004 and Miyashita et al., 2010). High abundances were achieved rapidly because of rapid embryonic development combined with parthenogenetic reproduction, which was favoured by temperatures between 23 and 30°C (Marazzo & Valentin 2004). High abundances of P. avirostris were achieved rapidly at S2 because of the influence of favourable temperatures and its parthenogenetic reproduction. Surprisingly, marine cladocerans have been little studied, compared

to the many studies on other planktonic crustaceans in Daya

Bay. The importance of P. avirostris in Daya Bay seems to be under-appreciated, click here AG 14699 given its high densities and important trophodynamic role. The use of plankton nets of different mesh-size can affect the resulting size-frequency distributions of mesozooplankton. Generally, smaller mesozooplankton can be collected abundantly in nets of finer mesh (Tseng et al. 2011). In this study, plankton nets of 505 μm mesh size were used to sample zooplankton, which would result in the escape of some smaller zooplankton and the incorrect assessment of the zooplankton community. Some species were neglected, namely, the ones whose body length < 0.2 mm, such as Pavocalanus, Oithona and Corycaeus, which also occur with high abundances in the study area ( Lian et al. 1990). Although there were a few defects in the sampling methodology, the average abundance of cladocerans was as high as 1360 indiv. m− 3 and accounted for 21.8% of the total zooplankton abundance before the Nuclear Power Plant came into operation ( Cai 1990). The question whether Penilia avirostris from the Dapeng Cove area was accidentally or factually dominant in this short period of time will be

addressed in the future on the basis of long-term monitoring. “
“In the Baltic Sea, as in other European seas, Sulfite dehydrogenase benthic invertebrates make up the largest proportion of non-indigenous species (Streftaris et al. 2005). Some 45 non-indigenous benthic species have so far been recorded in the Baltic (Baltic Sea Alien Species Database, 2010, Woźniczka et al., 2011 and Rudinskaya and Gusev, 2012). Some of these species, like Mya arenaria Linnaeus, 1758 and Amphibalanus improvisus (Darwin, 1854) were introduced into the Baltic more than one hundred years ago and have become a permanent feature of the sea’s macrofauna. But around half of the non-native species that have established populations were introduced after 1950 and within a short time gave rise to significant changes in the composition and structure of the Baltic macrofauna.