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Bandar-e Anzalī, Iran

Bagheri S.,Universiti Sains Malaysia | Bagheri S.,Inland Waters Aquaculture Institute | Mansor M.,Universiti Sains Malaysia | Wan Maznah W.O.,Universiti Sains Malaysia | Negarestan H.,Iranian Fisheries Research Organization
Proceedings of the International Offshore and Polar Engineering Conference

The study was conducted from January 2008 to December 2008, focused on spatial and temporal distribution of Mnemiopsis leidyi and zooplankton populations in the south-western area of the Caspian Sea. In summer and winter M. leidyi abundance and biomass values were between 1900 ± 1400 ind/m 2, 110 ± 220 ind/m 2 and 370 ± 250 g/m 2, 1.0 ± 1.3 g/m 2, respectively. The most individuals of a ctenophore (about 90%) were < 5 mm in length. A total of 19 zooplankton species were identified. Among them seven species were merozooplankton and 12 species were holozooplankton. The annual mean zooplankton abundance was recorded 5300 ± 1400 ind/m 3 which were lower than the previous years. The mass occurrence of M. leidyi appears to be one of the most important factors that reduce the zooplankton species and abundance, hence degrade the Caspian Sea natural ecosystem. Copyright © 2010 by The International Society of Offshore and Polar Engineers (ISOPE). Source

Bagheri S.,Inland Waters Aquaculture Institute | Turkoglu M.,Canakkale Onsekiz Mart University | Abedini A.,Inland Waters Aquaculture Institute
Turkish Journal of Fisheries and Aquatic Sciences

This study concentrated on temporal distribution and species composition of phytoplankton connected with physicochemical variations between January 2003 and November 2004 in the South Western Caspian Sea. During the study, 75 phytoplankton were distinguished in total and average phytoplankton densities in 2003 and 2004 were 1.47×105±6.05× 104and 1.97×105±7.18×104 cells L-1, respectively. Contributions of diatoms (66.0% in 2003; 57.0% in 2004) and cyanophytes to total phytoplankton (17.0 in 2003; 36.0% in 2004) were higher than any other group. Diatoms Dactyliosolen fragilissimus and Thalassionema nitzschioides, and cyanophytes Oscillatoria sp. and Anabeanopsis raciborskii provided the biggest contributions to the total phytoplankton. Average DIN concentration in 2003 was higher (3.86±1.65 μM) than the average in 2004 (3.37 ± 1.13 μM). However, average DIP concentration in 2003 was lower (1.45±1.37 μM) than the average in 2004 (1.99 ± 0.67 μM). Average DIS concentration was two-fold higher than average DIN concentration. Average DIN:DIP without NH4 (2.66 ± 1.66 in 2003; 1.69 ± 1.17 in 2004) and DIS:DIP ratios (5.61±3.44 in 2003; 3.93±2.49 in 2004) were clearly lower than Redfield ratios. Nutrient ratios and phytoplankton densities revealed that system was eutrophic © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey. Source

Bagheri S.,Inland Waters Aquaculture Institute | Niermann U.,Marine Ecology | Mansor M.,Universiti Sains Malaysia | Yeok F.S.,Universiti Sains Malaysia
Journal of the Marine Biological Association of the United Kingdom

The mesozooplankton of the south-western Caspian Sea, off Anzali, sampled from 1996-2010, had undergone severe changes, especially after the year 2001, when the invasive ctenophore Mnemiopsis leidyi bloomed for the first time. Native species vanished or decreased, while invasive species such as Pleopis polyphemoides, Acartia tonsa, M. leidyi and the larvae of Balanus sp., plus Hediste diversicolor dominated the zooplankton. It could be stated that the increasing amount of nutrients since the early 1980s led to a decrease of endemic species and smoothed the way for opportunistic invader species, which outcompeted and depleted the endemic species in their turn. However, the major changes in the zooplankton community and possibly the blooming of M. leidyi during 2001-2002 were triggered by changing weather patterns, when a period with heavy rain at the end of the 1990s was followed by a prolonged drought (2001-2002). It is not clear to what extent M. leidyi was responsible for the disappearance of endemic Copepoda and Cladocera species such as Eurytemora grimmi, Limnocalanus grimaldii, Cercopagis pengoi, and Polyphemus exiguous, because the mesozooplantic invader species seemed to be more successful competitors than the endemic Caspian Sea fauna. Compared with other areas of the Caspian Sea, the development of the M. leidyi stock was moderate in the area under investigation. Mnemiopsis leidyi numbers and biomass increased from the beginning of sampling in 2001 to about 600A n.m-3 and 40-60A g wet weightA m-3 until 2003. Since then the stock oscillated in this range until 2010. © 2013 Marine Biological Association of the United Kingdom. Source

Mertens K.N.,Ghent University | Takano Y.,Institute for East China Sea Research ECSER | Yamaguchi A.,Kobe University | Gu H.,Third Institute of Oceanography | And 5 more authors.
Systematics and Biodiversity

Kolkwitziella acuta is a cyst-forming dinoflagellate with a unique tabulation, occurring in freshwater to brackish environments of Eurasia and the USA. Based on the unique thecal plate arrangement, this species was previously interpreted as a missing link in the evolution between the genus Protoperidinium and the Diplopsalioideae. We isolated living K. acuta cysts from the south-western Caspian Sea and the central Baltic (Finland), and re-established the cyst-theca relationship. The cysts had a distinctive polar and dorsoventral compression and a characteristic wrinkly texture. The plate formula of the thecate stage was Po, X, 4′, 2a, 7″, 3c+t, ?s, 5″′, 1″″. Large subunit (LSU) and small subunit (SSU) ribosomal DNA sequences obtained through single-cell PCR of these cysts reveal that this species is close to Protoperidinum excentricum which belongs to the Excentrica section of the genus Protoperidinium. We suggest that it evolved from the genus Diplopsalis through a split of the apical and anterior intercalary plates. Furthermore, that the split of the antapical plates occurred several times independently in the evolution of Protoperidinium and Diplopsalioideae and is therefore a polyphyletic trait. The cyst of Kolkwitziella is considered an indicator of low salinities, specifically between 0 and 22 psu. Geochemical analysis of the cyst walls suggests a heterotrophic mode of nutrition. © The Trustees of the Natural History Museum, London 2015. All Rights Reserved. Source

Fallah F.J.,Islamic Azad University at Lahijan | Khara H.,Islamic Azad University at Lahijan | Roohi J.D.,Inland Waters Aquaculture Institute | Boorani M.S.,Inland Waters Aquaculture Institute
Comparative Clinical Pathology

The purpose of this study was to assess of some hematological parameters of Esox lucius collected from Anzali wetland from fall 2010 to summer 2011. Variations in hematological parameters such as hematocrit (Ht), hemoglobin concentration (Hb), erythrocyte (RBC) and leukocyte (WBC) counts, mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), lymphocytes, monocytes, neutrophils, and eosinophils of fish were compared according to age and seasonal differences. Analysis of variance showed significant differences in values of white blood cell (WBC), red blood cell (RBC), MCV, MCH, lymphocytes, monocytes, and eosinophils between ages. Statistical analysis revealed significant differences in RBC and WBC between all seasons. However, there were no significant differences in Ht, Hb, MCHC, MCH, MCV, neutrophils, lymphocytes, monocytes, and eosinophils between all seasons. Results of current study may be helpful in establishing a hematological data bank for this species including standard values of blood parameters. © 2013 Springer-Verlag London. Source

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