Physiological characteristics of the ctenophore Beroe ovata in Caspian Sea water

Kıdeyş, Ahmet Erkan
Anninsky, BE
Shiganova, TA
Roohi, A
Tabari, MR
Youseffyan, M
Rostamian, MT
Rostami, H
Negarestan, H
Riparian countries of the Caspian Sea have been evaluating the pros and cons of the predatory ctenophore Beroe ovata as a control agent against the invasive ctenophore Mnemiopsis leidyi, which has enormous adverse impacts on the fishery resources as well as on the biodiversity in this once fertile sea. To assess the viability of B. ovata establishment in the Caspian Sea, the survival and some physiological characteristics (feeding, respiration, reproduction and growth) of the predatory ctenophore were studied in Caspian Sea water (12.6 ppt salinity) conditions using animals transported from the Black and Marmara Seas to a laboratory on the Iranian Caspian coast. The findings of the study showed that when salinity was gradually decreased from 22 to 12.6 ppt, B. ovata were able to adapt well to Caspian Sea water. Most of the predatory ctenophores began to swim actively and to feed on M leidyi within 15 to 30 min following each step of acclimation. The feeding rate of B. ovata ranged from 14 to 765% of body wet weight and was highest for smaller individuals (i.e. 13 to 16 nun). Over the measured weight range of 0.23 to 3.87 g wet wt, the weight-specific respiration rate was independent of weight. The daily specific growth rate of adult ctenophores was 7 to 11% of body wet wt. B. ovata specimens were spawned and their eggs were hatched in Caspian Sea water, but the larvae survived for only a few hours. The energy budget of B. ovata calculated from food consumption, respwiration and growth rates revealed a mean assimilation efficiency of 0.72 +/- 0.1, a gross growth efficiency (K-1) of 0.48 +/- 0.12 and a net efficiency (K-2) of 0.66 +/- 0.06. Based on these physiological data, we suggest that in the Caspian Sea, B. ovata will be able to ingest M. leidyi intensively. However, concerning the reduction of the M leidyi population and consequently the reversal of its adverse impact on this ecosystem, the failure of larval growth observed under experimental conditions (most probably due to poor handling) remains the main obstacle to overcome in the successful establishment of B. ovata in the Caspian Sea.


Reproduction of the ctenophore Beroe ovata in the Caspian sea Water
Mirzajani, Ar; Shiganova, T.; Finenko, G.; Bagheri, S.; Kıdeyş, Ahmet Erkan; Roohi, A. (2007-01-01)
The experiments with Beroe ovata showed that this ctenophore can survive and reproduce in the Caspian Sea water, though at far lower rate than in the Black Sea; larval growth in the Caspian Sea water was also slower and mortality higher. Maximum fecundity of 2210 and 240 eggs recorded in laboratories of Turkey and Iran, respectively. About 34 to 100% of eggs in the Caspian Sea water could not develop and hatch. Larvae were at different stages of development, usually with size between 1.2 to 2mm. The highest...
Chemical composition, respiration and feeding rates of the new alien ctenophore, Beroe ovata, in the Black Sea
Finenko, GA; Anninsky, BE; Romanova, ZA; Abolmasova, GI; Kıdeyş, Ahmet Erkan (2001-05-01)
Maximum daily rations of the ctenophore Beroe ovata Brugiere and predatory impacts on the Mnemiopsis leidyi A. Agassiz population were estimated via digestion time, prey biomass and predator and prey density in Sevastopol Bay and adjacent water regions. Digestion times ranged from 0.5 to 5.2 h and depended on the prey/predator weight ratio. Overall, the mean daily ration was 45% of B. ovata wet weight. Preliminary conclusions are given on the B. ovata population as an effective control of the M. leidyi popu...
Impact of a new invasive ctenophore (Mnemiopsis leidyi) on the zooplankton community of the Southern Caspian sea
Roohi, Abolghasem; Yasin, Zulfigar; Kıdeyş, Ahmet Erkan; Hwai, Aileen Tan Shau; Khanari, Ali Ganjian; Eker-Develi, Elif (2008-12-01)
The invasive ctenophore Mnemiopsis leidyi (Agassiz), which was transported from the Black Sea into the Caspian Sea at the end of the 1990s, has negatively affected the ecosystem of the Caspian Sea. Zooplankton abundance, biomass and species composition were evaluated on the Iranian coast of the Caspian Sea during 2001-2006. A total of 18 merozooplankton (13 species composed of larvae of benthic animals) and holozooplankton (four Copepoda and one Cladocera) species were identified. The total number of zoopla...
Feeding, respiration and growth of ctenophore Beroe cf ovata in the low salinity conditions of the Caspian Sea
Kıdeyş, Ahmet Erkan; Anninsky, BE; Shiganova, TA; Roohi, A; Tabari, MR; Youseffan, M; Rostamiya, MT (2004-01-01)
The ctenophore Beroe cf ovata, which spontaneously entered the Black Sea in the 1990s and suppressed the previous ctenophoran invader Mnemiopsis leidyi by its predatory impact, is currently considered for intentional introduction to the Caspian Sea as well. In order to assess its impact on Mnemiopsis in the Caspian, Beroe was transported during 2002 from the Black Sea and the Bosporus to the Khazerabad laboratory (Mazandaran), on the Caspian coast of Iran, where experiments on its survival in Caspian water,...
Current state of overfishing and its regional differences in the Black Sea
OGUZ, Temel; Akoğlu, Ekin; Salihoğlu, Barış (2012-03-01)
Long-term (1950-2006) changes of fish landings in combination with some ecosystem indicators are used to evaluate the status and sustainability of the Black Sea fishery. Following the depletion of large pelagic predator and demersal fish stocks during the 1950-1960s, the main fishery was targetted on small and medium pelagics that declined abruptly to similar to 200 kton (kton 10(3) t) at 1989-1991 after a highly productive (similar to 750 kton) but overfished state in the 1980s. Thereafter, total landings ...
Citation Formats
A. E. Kıdeyş et al., “Physiological characteristics of the ctenophore Beroe ovata in Caspian Sea water,” MARINE ECOLOGY PROGRESS SERIES, pp. 111–121, 2004, Accessed: 00, 2020. [Online]. Available: