Recursos de colección

Aquatic Commons (41.069 recursos)

The Aquatic Commons is a thematic digital repository covering the natural marine, estuarine /brackish and fresh water environments . It includes all aspects of the science, technology, management and conservation of these environments, their organisms and resources, and the economic, sociological and legal aspects.

Subject = Ecology

Mostrando recursos 1 - 20 de 178

  1. Spatial and temporal patterns of benthic macrofauna in Gorgan Bay, south Caspian Sea, Iran

    Ghorbanzadeh Zaferani, S.Gh.; Machinchian Moradi, A.; Mousavi Nadushan, R.; Sari, A.R.; Fatemi, S.M.R.
    We quantified the distribution, abundance and assemblage structure of macrofauna at 22 stations in Gorgan Bay, seasonally in 2012-2013. Also, depth, temperature, salinity, DO, TOM and sediment particle size were measured in each station. The highest concentration of TOM was measured near the western littoral zone (10.22) while the mouth part and north-eastern area was characterized by the lowest values (2.65 % and 4.69). A total of 31658 individuals belonging to 12 families and 14 species were identified. Polychaeta with 3 species was the most dominant group in terms of abundance. The four most abundant taxa making up 85% of...

  2. Short communication: A study of food consumption of the deepwater goby, Ponticola bathybius (Kessler, 1877), during spring migration in the southern Caspian Sea

    Tajbakhsh, F.; Abdoli, A.A.; Rajabi Maham, H.; Hashemzadeh Segherloo, I.; Kiabi, B.
    The gobies exhibit a main role in the general production of the Caspian Sea due to their species diversity and unexploited stocks. So, of the 80 fish species known from Iranian part of the Caspian Sea, 10 of them are gobies. The deepwater goby, Ponticola bathybius (Kessler, 1877), Gobiidae, is a native species in the Caspian Sea which settles on sandy and shelly substrates and, in a few numbers, on firm silt down to 75 meters. The presence of predators such as Acipenseridae and prey items as Clupeonella sp. could be effective in the abundance of gobies. Gobies fishes are...

  3. Short communication: Ecological larval fish groups in Chabahar Bay in relation to day/night and monsoon variations

    Nasiri, H.R.; Rabbaniha, M.; Attaran-Fariman, G.; Mousavi Golsefid, S.A.
    Studies on larval fish abundance allow important inferences about the spawning grounds, reproduction season and migration pattern of fishes. Larval densities can also be used to estimate the abundance index, which in turn can be correlated to the fisheries yield, and provide an alternative approach for measuring the size of the spawning stock. Previous studies in this ecosystem have focused on the abundance of fish larva without consideration of daily fish larva variations. ... In this research we consider the monsoon as an important phenomenon, affecting the daily fish larval distribution.

  4. Diversity of eukaryotic plankton of aquaculture ponds with Carassius auratus gibelio, using denaturing gradient gel electrophoresis

    Dong, X.; Zhao, W.; Lv, L.; Zhang, H.; Lv, F.; Qi, Z.; Huang, J.; Liu, Q.
    PCR-denaturing gradient gel electrophoresis (DGGE) and canonical correspondence analysis (CCA) were used to explore the relationship between eukaryotic plankton community succession and environmental factors in two aquaculture pond models with gibel carp Carassius auratus gibelio. The main culture species of pond 1 were gibel carp and grass carp, and the combined density was 46224 fingerling/ha (gibel carp/grass carp/silver carp/bighead carp, 17:4:6:1). The main culture species of pond 2 was gibel carp, and the combined density was 37551 fingerling/ha (gibel carp/silver carp/bighead carp, 52:1:1). Water samples were collected monthly. The results showed that the annual average concentrations of TP and PO_4-P...

  5. Size structure of finescale razorbelly minnow, Salmostoma phulo (Cyprinidae) inhabiting a coastal river of Bangladesh

    Chaklader, M.R.; Siddik, M.A.B.; Hanif, M.A.; Nahar, A.
    The aim of this study was to report the size structure of finescale razorbelly minnow, Salmostoma phulo in the Payra River, Southern Bangladesh, based on length-frequency distribution (LFD), sex ratio (SR), length-weight relationships (LWR), length-length relationships (LLR), condition factors (allometric K_A; Fulton’s, K_F; relative, K_R and relative weight, W_R) and form factor (a_3.0). A total of 306 individuals ranging from 6.00–10.70 cm in total length and from 1.26-9.20 g in body weight were collected using traditional fishing gear from January 2014 to November 2014. The overall sex ratio of the species did not reveal significant variation from the expected value...

  6. Phytoplankton of Aras dam reservoir (Iran): an attempt to assess water quality

    Mohebbi, F.; Riahi, H.; Sheidaei, M.; Shariatmadari, Z.
    The Aras reservoir, located in the north-west of Iran, plays an important role in fisheries, drinking and agricultural water supplies and recreational activities in the region. This study was performed to characterize the seasonal fluctuations of phytoplankton communities and their relationship with environmental factors in the Aras reservoir from August 2013 to May 2014. Sampling was carried out seasonally from 5 sampling locations. In each location three samples were taken for phytoplankton identification and enumeration, chemical analysis and chlorophyll a determination. In total, 72 species belonging to 5 divisions were determined. Cyanobacteria contained the highest density (74%) during the study...

  7. Short communication: Identification and morphometric descriptions of four dominant families of larval fishes in the estuary of Marudu Bay, Sabah, East Malaysia

    Rezagholinejad, S.; Ehteshami, F.; Arshad, A.; Amin, S.M.N.; Ara, R.
    Fish larvae are mostly ecologically and morphologically different in comparison with their adult counterparts along their development processes. They occupy different habitats, taking different food resources, and having different predators and different behaviour. During the larval phase, the fish develops from an egg to a larva which has all the fully functional organs. Many species have highly specialized larval morphologies, with various structures (e.g. strong spines on the head) that will be modified and lost upon transition towards adulthood. Fish larvae differ so much from their adults that they are often difficult to identify. Nonetheless, they need to be identified...

  8. Short communication: Ecological classification of southern zones of the Caspian Sea (Mazandaran Province), based on CMECS model

    Hoseinzadeh, M.A.; Owfi, F.; Gorjian Arabi, M.H.; Keshavarz, M.
    A coastal area is a confluence of land and marine ecosystems and includes the independent biological, ecological, and geological area. Increasing pressure on these areas can decrease the quality of marine habitats, and can even lead to the loss of sensitive habitats. In this regard, a “biotope” has been suggested as the most informative operational unit for research and management. These biotopes, however, have been specified by the dominant species; they depend on the seabed, they are stable, and sometimes are used synonymously with the word ecology. Habitat classifications are, therefore, most accurate and ecologically relevant at the biotope level...

  9. Short communication: Age, growth and mortality of Caspian spirlin, Alburnoides eichwaldii (De Filippi, 1863), from Aras River Basin in Turkey

    Cicek, E.; Sigirci, U.; Birecikligil, S.; Saylar, Ö
    The genus Alburnoides belongs to the Leuciscine cyprinids and is distributed in Europe and eastern parts of Asia. Only two subspecies have been consistently reported for Alburnoides bipunctatus (Heckel, 1858) from Turkey, A. bipunctatus eichwaldii and A. bipunctatus fasciatus. Just a few years ago, some taxonomic work focusing on the genus Alburnoides reported 4 new species from Turkey. Alburnus eichwaldii (De Filippi, 1863), described from the Kurpresso Tiflis (Kura River near Tbilisi, Georgia), is usually regarded as a Caspian Sea basin subspecies of A. bipunctatus. Recently, the species was considered to be a full species. ... However, there has not...

  10. Short communication: Age and growth of king nase, Condrostoma regium (Cyprinidae), from Bibi-Sayyedan River of Semirom, Isfahan, Iran

    Kiani, F.; Keivany, Y.; Paykan-Heyrati, F.; Farhadian, O.
    Age determination is an important step in fisheries management. The cyprinid fish Chondrostoma regium (Heckel, 1843) is widely distributed in Tigris-Euphrates basin and the Mediterranean basins of southeastern Turkey and the northern Levant. In Iran, it is found in Karun and Karkheh Rivers, the Hoor-al-Azim Marsh and also in Zayandehrud River and Bushehr basin. This species is not found in other basins of Iran. However, there is little information about its habitat requirements. ... The aim of the present study was to investigate the length-weight relationship and age and growth of C. regium population in Bibi-Sayyedan River of Semirom, Isfahan...

  11. Preliminary studies on the impact of fish cage culture rainbow trout (Oncorhynchus mykiss) on zooplankton structure in the southwestern Caspian Sea

    Bagheri, S.; Mirzajani, A.; Sabkara, J.
    The ecosystem of the Caspian Sea have been strikingly changed by human activities. This area has undergone significant ecological alterations and serious environmental degradation since the beginning of 1990s. The impact of fish cage culture on the zooplankton community was studied in the southwestern Caspian Sea, off Jafrud during January to April 2013. A total of 12 zooplankton belonging to 9 taxa were identified at the study area. Only one species of Cladocera (Pleopis polyphemoides), was present in our study. Acartia tonsa and Balanus improvisus were the most dominant species. Bivalvia larvae, P. polyphemoides (Cladocera) and Synchaeta sp. (Rotifera) occurred...

  12. Effects of environmental parameters and nutrients on phytoplankton communities around the shrimp farm complexes in Bushehr Province, in the Persian Gulf

    Aein Jamshid, Kh.; Mohsenizadeh, F.; Omidi, S.
    The aim of this work was to be informed and aware of the red tide conditions before the entering of algal blooms in seawater supply canals of the shrimp farm and hatchery complexes in Bushehr Province. Field investigations and monthly samplings have been carried out to determine environmental parameters, nutrients, chlorophyll–a and phytoplankton in the southern part of the input water channels of Mond, Delvar and Heleh farmed shrimp complexes from April to December 2011. The identified phytoplankton belonged to three classes of Bacillariophyceae, Dinophyceae and Cyanophyceae. 12 genera belonging to Dinophyceae, 25 genera to Bacillariophyceae and two genera to...

  13. Short communication: Identification, distribution, abundance and species composition of fish in the Chitgar Lake (Tehran Province of Iran)

    Ramin, M.; Bagheri, S.; Moradi, M.; Abbasi, K.; Mirzajani, A.; Doustdar, M.
    This study was conducted in the Chitgar Lake in 2014. Chitgar Lake, 130 hectares in area is an artificial lake located in the north-west of Tehran City, Iran. For the first time the seasonal sampling of fish was done by three fishing methods gill net, cast net and beach seine, and a random sample of 3160 fish was collected. Some morphometric and meristic factors of samples were studied in the laboratory, and the distribution, abundance and species composition were determined. According to the results obtained, 95% of fish population was comprised of aggressive species such as; Hemiculter leucisculus, Pseudoras boraparva...

  14. Co-invasion of anchor worms Lernaea cyprinacea (Copepoda: Lernaeidae) in some freshwater fishes of the Kor River Basin, southwest of Iran with some remarks on the ecological aspects of lernaeosis in the country

    Sayyadzadeh, G.; Esmaeili, H.R.; Ghasemian, S.; Mirghiyasi, S.; Parsi, B.; Zamanpoore, M.; Akhlaghi, M.
    In the present investigation, co-invasion of Lernaea parasite is reported in some fish species, collected from the Kor River Basin (Dorudzan Reservoir and Kor River), Southwest of Iran in 2010 and 2011. Lernaea cyprinacea parasites were isolated from the external surface of eye, lips, gills, nostrils, fins, operculum and body of Alburnus mossulensis, Capoeta aculeata, Capoeta saadii (all native cyprinids), Cyprinus carpio and Carassius auratus (exotic cyprinids). The highest infestation was found in endemic fish, C. aculeata with 61 ectoparasites in a single specimen of 348 mm TL. The greatest prevalence was found in C. auratus (100%) followed by C....

  15. Evaluation of effects of physico-chemical factors on chlorophyll-a in Shadegan International Wetland - Khouzestan Province - Iran

    Ghorbani, R.; Hosseini, S.A.; Hedayati, S.A.A.; Hashemi, S.A.R.; Abolhasani, M.H.
    Measurement of chlorophyll-a can be considered important to investigate the primary production of an ecosystem. This study aimed to investigate chlorophyll-a concentration, primary production and the factors affecting them in Shadegan Wetland located in Khouzestan Province - Iran. Sampling for measuring (NO3, PO4, BOD5, DO, pH, EC, salinity, temperature) was performed seasonally at five sampling stations of the wetland (Canal, Ragbeh, Khoroosi, Mahshahr and Atish), from March 2013 – through February 2014. Results showed that chlorophyll-a concentrations in Canal station were significantly higher than that in the other stations; however, there were no significant differences among the other sampling stations...

  16. Relationships between the physicochemical parameters and zooplankton in Eğirdir Lake (Turkey)

    Apaydın Yağcı, M.; Yağcı, A.; Dölcü, B.
    The zooplankton community structure in Eğirdir Lake (Isparta-Turkey) was studied monthly throughout an annual cycle (January 2010-December 2010). The zooplankton community was represented by three main groups: Rotifera, Cladocera and Copepoda, respectively comprised 89.62%, 7.78% and 2.60% of the total zooplankton abundance. Eğirdir Lake was dominated by the rotifera Polyarthra dolichoptera in September and October, that succeeded by cladocera Bosmina longirostris species during December. Canonical correspondance analysis (CCA) was used to relate species distribution to environmental factors. The variation in the species data was significantly (p<0.05) related to a set of environmental variables (conductivity, carbonate, pH, ammonium, organic substances, dissolved...

  17. Effects of Spartina alterniflora invasion on distribution of Moerella iridescens in a tidal flat of western Pacific Ocean

    Ge, B.M.; Zhang, D.Z.; Tang, B.P.; Bao, Y.X.; Cui, J.; Hu, Z.Y.
    The invasion of Spartina alterniflora significantly affected the local ecosystem of Western Pacific Ocean where Moerella iridescens lives. Five patches with different invasion stages of S. alterniflora were selected and the influence on distribution of M. iridescens was studied on the coast of Wenzhou Bay, China in 2007. The aggregated distribution pattern was proved by using Taylor's power regression and Iwao's plot regression methods (p<0.001). The densities were significantly affected by the factors of S. alterniflora invasion stage and season (p<0.001), but no significant effect of interaction (p=0.805) occurred. M. iridescens mainly clumped in the habitats of no invasion and...

  18. The reproductive biology and feeding habits of yellow fin seabream, Acanthopagrus latus (Houttuyn, 1782), in the northern Persian Gulf

    Vahabnezhad, A.; Kaymaram, F.; Taghavi Motlagh, S.A.; Valinassab, T.; Fatemi, S.M.R.
    Monthly samples of Acanthopagrus latus (Houttuyn, 1782) were used to determine (1) feeding habits and (2) reproduction characteristics of the species in relation to its size, spawning season and sex in the northern part of the Persian Gulf from January to December 2013. The smaller length classes of all samples were dominated by male fish. All gonads examined, were ovotestis during the spawning period from February till May. Male and female ovotestes were dimorphic in structure which represented a transitional stage in a protandrous sex change. Length at first sexual maturity of female A. latus was 24.40 cm. A. latus...

  19. Effects of boiled Jatropha kernel meal as a substitute for soybeans meal in diet of African mud catfish (Clarias gariepinus) fingerlings

    Alatise, S.P.; Ajiboye, G.E.
    A feeding trial was conducted in the laboratory for 8 weeks to evaluate the growth response of C. gariepinus fingerlings using boiled Jatropha kernel as the protein source in place of soybean meal. Four experimental diets (40% crude protein) were formulated, three of these diets contained boiled Jatropha kernel meal at varying levels of 0% 10%, 20%, and 30% while the diet without boiled Jatropha kernel meal served as control. Fish fingerlings were fed weekly at 5% body weight. It was discovered that the percentage weight gain was significantly different (p<0.05) among the controlled diet and the experimental diets; specific...

  20. Whole rocky fresh water prawns, Caridina africana as replacement for fish meal in diets for African catfish (Clarias gariepinus)

    Oyekanmi, F.B.; Omoniyi, I.T.; Akegbejo-Samsons, Y.
    Specimens of Caridina africana were oven dried at 110~'C for 24 hours and refrigerated at 200~'C prior to proximate analysis. Whole rocky freshwater prawn meal (WRFWPM) was evaluated as a dietary replacement for fish meal in the diet of C. gariepinus fingerlings. The diets were fed to triplicate groups of C. gariepinus fingerlings (10.6 ~c 0.08g) reared in concrete tanks, to assess the effects of its partial or complete replacement with fish meal for 90 days. The diets comprised a control which contained fish meal as a protein source; 0% and four others on weight basis at 25%, 50%, 75%...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.