We describe the effect of gelatinous plankton – Aurelia aurita and invaders Mnemiopsis leidyi and Beroe ovata – on fish (eggs, larvae, feeding, and stocks) in the Black Sea and Sea of Azov, based on field data and the relevant literature. Representatives of three ecological groups of fish were chosen as examples: planktivorous anchovy typical of warm-water conditions, planktivorous sprat of tem...

The occurrence of the ctenophore Mnemiopsis leidyi as a new invasive species in the Baltic Sea and the potential consequences for fish stock recruitment was investigated in spring 2007. The study focused on the Bornholm Basin, which serves as the major spawning ground for cod and sprat, the commercially most important fish stocks in the Baltic. The distribution pattern of M. leidyi revealed a s...

Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience and biogeography). A few ctenophore species including, most notably, Mnemiopsis leidyi, are considered as invasive species, adding to the significance of studying ctenophore ecology. Despite the growing interest in ctenophore biolo...

A high-resolution digital imaging system, the zooplankton visualization and imaging system (ZOOVIS) was deployed in the mid-region of Chesapeake Bay to investigate the fine-scale distribution of small individuals of the lobate ctenophore Mnemiopsis leidyi. Counts of individuals, mostly ,5 mm, were enumerated from each frame of ZOOVIS and merged with data from a conductivity-temperaturedepth to ...

mnemiopsis leidyi population activities first were recorded during the coastal observations in 2001 in which its population considerably increased afterward and now sustained the southern caspian sea. maximum summer-autumn m. leidyi abundance was recorded in euphotic layer in 2002 (851±85 ind.m-3) and maximum biomass was in 2001 with 48.1±14.4 g.m-3) while minimum were in aphotic layer. in year...

In March 2008, we conducted a survey to investigate the distribution and abundance of the invasive ctenophore Mnemiopsis leidyi in the Bornholm Basin after the winter period. Compared to the situation in November 2007 the centre of the distribution had shifted towards the deeper parts of the Basin where temperatures were higher than at the surface. Furthermore, we found a decrease in average si...

The recent invasion of the comb jelly Mnemiopsis leidyi into northern European waters is of major public and scientific concern. One of the key features making M. leidyi a successful invader is its high fecundity combined with fast growth rates. However, little is known about physiological limitations to its reproduction and consequent possible abiotic restrictions to its dispersal. To evaluate...

The ctenophore Mnemiopsis leidyi A. Agassiz, 1865 is known to be eaten by the scyphomedusan Chrysaora quinquecirrha (Desor, 1948), which can control populations of ctenophores in the tributaries of Chesapeake Bay. In the summer of 1995, we videotaped interactions in large aquaria in order to determine whether M. leidyi was always captured after contact with medusae. Surprisingly, M. leidyi esca...

A short synthesis of the present state of the ctenophore, Mnemiopsis leidyi, invasion in the Black Sea is given, together with a brief review of its status in other areas of the Mediterranean basin. The impact of M. leidyi on the main components of the pelagic community, mesozooplankton, ichthyoplankton and ®sh resources, based on published data and new ®eld studies (1992±1997) are analysed. Th...

Episodic blooms of voracious gelatinous zooplankton, such as the ctenophore Mnemiopsis leidyi, affect pools of inorganic nutrients and dissolved organic carbon by intensive grazing activities and mucus release. This will potentially influence bacterioplankton activity and community composition, at least at local scales; however, available studies on this are scarce. In the present study we exam...