Interactions between the invading ctenophores Mnemiopsis leidyi (A. Agassiz) and Beroe ovata Mayer 1912, and their influence on the Pelagic ecosystem of the Northeastern Black Sea

Seasonal refugia, shoreward thermal amplification, and metapopulation dynamics of the ctenophore Mnemiopsis leidyi in Narragansett Bay, Rhode Island

“…The importance of Mnemiopsis leidyi as a planktonic predator has been documented by a large body of research on its feeding capabilities (Kremer 1975;Reeve et al 1978;Waggett and Costello 1999) and trophic impacts (Kremer 1979;Shiganova et al 2001;Sullivan et al 2001). These predatory capabilities underlie the importance of recent range expansion patterns for M. leidyi.…”

“…We propose that earlier occurrences of M. leidyi during recent years are due to amplification of pulsed spring warming events that permit early reproduction in the shallow embayments that serve as source regions for M. leidyi in Narragansett Bay. We further suggest that the source-sink perspective we describe is relevant not only to Narragansett Bay but other temperate regions of the world persistently occupied by M. leidyi.The importance of Mnemiopsis leidyi as a planktonic predator has been documented by a large body of research on its feeding capabilities (Kremer 1975;Reeve et al 1978;Waggett and Costello 1999) and trophic impacts (Kremer 1979;Shiganova et al 2001;Sullivan et al 2001). These predatory capabilities underlie the importance of recent range expansion patterns for M. leidyi.…”

“…These predatory capabilities underlie the importance of recent range expansion patterns for M. leidyi. Invasion of regions outside its historical distributions have resulted in dramatic planktonic community alterations in regions such as the Black Sea (Shiganova et al 2003) and Sea of Azov (Studenikina et al 1991). Although perhaps less acclaimed than these spatial range expansions, records of temporal range expansion within its endemic range can also cause important changes in planktonic community dynamics (Sullivan et al unpubl.…”

Consumption rates and prey preference of the invasive gastropod Rapana venosa in the Northern Adriatic Sea

“…It is largely recognised that when an alien species finds optimal conditions for its growth and reproduction (i.e. large availability of food and a suitable habitat for reproduction), the lack of an efficient control on it by competitors/predators could determine a collapse of the entire trophic web; well-known examples of such situations are the bioinvasion of the comb jelly Memniopsis leidyi in the Black Sea/Caspian Sea (Shiganova et al 2001;Shiganova et al 2003) or of the European green crab Carcinus maenas along the coasts of United States and Australia (Grosholz and Ruiz 1995;Walton et al 2002).…”

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“…However, he also estimated higher L ∞ (33.5 cm for males and 40.4 for females) and lower K (0.17 for males and 0.15 for females) than this study. Besides exploitation pressure for whiting stocks in the Black Sea, variations in the growth rates may be the result of biotic and abiotic factors such as temperature, food availability, competition, (Gerritsen et al, 2003;Shiganova et al, 2003). Different estimation of growth rates may be the results of length composition differences between years within a stock due to different fishing pressure or/and probably due to errors associated with estimates of mean length at age.…”