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Aquatic Commons (38.811 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 25

  1. The length weight relationship and condition factor of the Banded Jewel fish (Hemichromis fasciatus Peters) from Kainji Lake, Nigeria

    Yem, I.Y.; Sani, O.A.; Mshelia, M.B.; Onimisi, H.U.
    The length weight relationship and condition factor of Hemichromis fasciatus from Kainji Lake was studied. One hundred and twenty seven fish samples of total length ranging from 6.50cm 15.50cm and weigh between 4.00g and 60.00g collected between August 2006 and June 2007 were analyzed. Results showed that a, b and r - values were 0.0042, 3.442 and 0.966 respectively, while the condition factor (CF) values varied from 0.67 2.42 with mean of 1.203. The fish exhibited positive allometric growth pattern. The condition of the lake is favourable for the survival of the fish species.

  2. A survey of ectoparasites associated with 3 species of fish Auchenoglanis occidentalis, Oreochromis niloticus and Bagrus bayad in River Benue, Makurdi, Benue State, Nigeria

    Nyaku, R.E.; Okayi, R.G.; Kolndadacha, O.D.; Abdulrahman, M.
    A survey of ectoparasites of three species of fish (Oreochromis niloticus, Auchenoglanis occidentalis and Bagrus bayad) of River Benue was carried out for a period of three weeks. Samples were collected directly from fishermen, at the river side (River Benue) in a plastic bucket and were carried to the laboratory. A smear samples from the skin were taken. Fins were cuted and gills were dissected and examine individually in saline solution in a Petri dish and platyhelminthes parasites as the most common ectoparasites of threes three species (Oreochromis, Auchenoglanis, and Bagrus). A total number of five hundred and seventy two...

  3. Some ecological indices of the Caspian Sea Amphipoda at different depths Guilan offshore

    Mirzajani, A.R.; Kiabi, B.H.; Nezami, S.A.
    In the present study, some ecological factors were studied for Amphipoda at different depths. The Shannon, Margalef, and Hill indices were used to determine the species diversity, richness and evenness, respectively. In addition, the association and niche overlap values were estimated. Indices of species richness and diversity were highest at 50 and 100m depths, respectively. The ordination of depths shows that the highest dissimilarity was at 20m depth and the lowest dissimilarity at 100 meter. Results of interspecific association and specific overlap of species show that only a few species could have similar ecological requirements. Results show that Paraniphargoides derzhavini...

  4. Kepadatan kerang lumpur Anodontia edentula Linnaeus, 1758 kaitannya dengan parameter lingkungan di Kabupaten Muna

    Rochmady, R; Omar, Sharifuddin Bin Andy; Tandipayuk, Lodewyck S.
    The research aims to analyze the density of mud clams Anodintia edentula Linnaeus, 1758 relation to environmental parameters, covering organic material content and composition of sediment in Muna regency. Research carried out in coastal Lambiku and Tobea Island. The sample collection begins in March until May 2011, intervals collection example once a month for three months. A collection of mud clams example in a plot trasek (Line Transect Plot) is determined (purposive sampling). A plot observation based on three categories, Plot I near coast, Plot II the transition and Plot III far from the beach, intervals 50m each a plot...

  5. Struktur dan komposisi jenis mangrove Desa Bonea dan Kodiri, Kabupaten Muna, Sulawesi Tenggara

    Rochmady, R
    The condition of mangrove ecosystem in Kodiri village is in good condition, because the management effort has been done by indigenous community self-supporting. Mangrove in the village of Bonea classified as damaged, due to the high utilization rate, especially the taking of firewood. The research aimed to analyze the structure and composition of mangrove vegetation in Bonea village, Lasalepa district and Kodiri village, Lohia district. Relative density parameters, relative closure, relative closure type and Important Value Index (INP) are used as indicators to describe the structure and composition of mangrove vegetation. The study was conducted from June to December 2014...

  6. Aspek bioekologi kerang lumpur Anodontia edentula (Linnaeus, 1758) (Bivalvia: Lucinidae) di perairan pesisir Kabupaten Muna

    Rochmady, R
    The study was conducted in Tobea Island and coastal Lambiku for analysis: 1) biology aspects, 2) environmental aspects. Data were analysed to see the difference in the two locations using t-test analysis (student) and descriptive. The analysis showed that mangrove ecosystems in Tobea island, the closure of the (51%) and density (1.000 trees ha-1), in coastal Lambiku close (43%) and density (944 trees ha-1). Biological aspects of the growth population of mudclams in the Tobea Island (L∞= 65.6 mm, K= 1.18) lower than in coastal Lambiku (L∞= 73,75 mm, K= 0.73). Results of the t-test (student), morphometric characters of mudclams...

  7. Composition and abundance of macro-invertebrate community in earthen ponds of Akscoa Fish Farm Oruk Anam L.G.A., Akwa Ibom State, Nigeria

    Unanam, A.E.; Udoinim, M.M.; Effiong, H.S.
    Composition and abundance of macro-invertebrates, in Akwa Ibom State College of Agriculture, Fish Farm in UrukAnam Local Government Area, Nigeria, was studied from (December 2005 to May, 2006). Collections of samples were made with benthic net at weekly intervals. Stocked and unstocked ponds were selected for the study. The stocked ponds had 122 individuals macro invertebrates while unstocked pond had 160 number of individuals. The two ponds were dominated by Diptera followed by Coleoptera with single individual species. Groups which are regarded as clean water fauna were absent in both ponds. Generally, the ponds were poor in terms of number...

  8. Quantitative (Chlorophyll-a) and qualitative (species composition) seasonal fluctuations of phytoplankton in Lavan coastal waters (North of the Persian Gulf)

    Roohani Ghadikollahy, K.
    Phytoplankton species composition, as well as the amount of Chlorophyll-a and their relation to physicochemical parameters, were studied. The samples were collected monthly from October 1996 until September 1997 in two stations, i.e., Lavan and Douberkeh coastal waters. In this study, 65 phytoplankton species related to 3 groups of diatoms, dinoflagellates and Blue-Green Algae (24 genus and 44 species of diatoms, 6 genus and 18 species of dinoflagellates and 3 genus blue-green algae) were identified. Diatoms and dinoflagellates were abundant during periods of low salinity and temperature (November-May), while blue-green algae were abundant from July till September. Although the amount...

  9. Physico-chemical characteristics and zooplankton community of a dug-out pond in Ekpoma, Edo State, Nigeria

    Unanam, A.E.; Edokpayi, C.A.
    The physico-chemical characteristics and zooplankton community of a dug-out pond along Ukhun Road, Ekpoma, Edo State was studied for a period of six months (August, 1999 January, 2000). Composite water and zooplankton samples from different sections of the pond were taken for the study, at fortnightly intervals. The range of values observed for the parameters were temperature 28-31 degrees C (air) and 25-28 degrees C (water); Electrical conductivity (36.50-67.30 Scm-1) TSS 0.190.99mg/l; TDS (14.20-33.4mg/l); pH (6.15-6.70); DO (4.6-9.3mg/l); BOD (2.2-4.9mg/1); Chlorinity 35.50ppm); Total alkalinity (42.7-67.10mgCaC03); Phosphate-phosphorus (4.43-7.18mg/l) and Nitrate-Nitrogen (0.4-0.95mg/l). Heavy metals concentrations were generally low except for iron, which...

  10. An observation on the acquisition or loss of trematode (Clinostomum tilapiae) by Tilapia (Oreochromis niloticus) in culture systems

    Adeyemo, A.O.; Agbede, S.A.
    The acquisition or loss of Clinostomum tilapiae parasites by Oreochromis niloticus was studied. Four groups of 25 healthy fishes were stocked in the upper part of serial experimental ponds, while another four groups of 25 infected fishes were also stocked at the rear part of the serial experimental ponds. All the groups were fed at 3% body weight with the same compounded fish feed. Acquisition or loss of parasites and growth was monitored for a period of six months. The mean relative growth rate was 11.04kg/month for the healthy fishes and 5.62g/month for the infected fishes. The mean specific growth...

  11. Perbandingan karakter morfometrik kerang lumpur Anodontia edentula, Linnaeus 1758 di pulau Tobea dan pesisir Lambiku, Kecamatan Napabalano, Kabupaten Muna

    Rochmady, R; Omar, Sharifuddin Bin Andy; Tandipayuk, Lodewyck S.
    The objective of the research was to aim the morphometric characters of mudclams, Anodontia edentula Linnaeus, 1758 in Tobea Island and in the coast of Lambiku, Napabalano District of Muna Regency. The research carried out in Tobea Island and in the coast of Lambiku was to analyse morphometrics character of mudclams. Data were analysed to perceive the comparison of morphometrics characters of mudclams in Tobea Island and in the coast of Lambiku by using t-test (student) and descriptive analysis. The results of t-test (student) analysis showed morphometric characters of mudclams in Tobea Island and in the coast of Lambiku significantly...

  12. Food, feeding ecology and condition index of the brackish river prawn Macrobrachium macrobrachion (Herklots, 1851) (Crustacea, Decapoda, Palaemonidae) in the Cross River Estuary, South-Eastern Nigeria

    Job, B.E.
    Investigations were carried out to study the food, feeding ecology and condition index of the brackish river prawn, Macrobrachium macrobrachion (HERKLOTS, 1851). One thousand, nine hundred and ninety-seven live specimens which comprised of individuals representing all size groups of the prawn were studied. The specimens were obtained from the commercial artisanal catches at Nsidung Beach along Calabar River (40301N and 80201E). Although algae formed the bulk of the diet of the prawn with 44.61% occurrence, other food items: detritus (24.30%), crustacean remains (23.14%), mud/sand particles (6.23%), fish bones and scales (2.14%) and small worms (0.21 %), were also consumed. The...

  13. Macroinvertebrate study of Caspian Sea river estuaries in Guilan Province

    Mirzajni, Alireza; Yosefzad, Esmaiel; Sayad Rahim, Mostafa; Zahmatkesh, Yagobali; Gorbanzadeh Zaferani, Sid Gasem; Sedigi Savadkohi, Omid
    Macrobenthos were performed the main group of the Caspian Sea funa while they have not completely attentived espacilly in estuaries environoments. In this survey were studied eghiteen river estuaries in Guilan province off Caspian Sea southwest. The macroinvertebrate sampling was conducted seasonally at egith station during winter 2009 to summer 2009. The macrobenthos organisms were sorted and identified as possible level in genus or species. The results presented fifteen orders including thirty six families. The most presentation of genus belongs to Chironomidae family with twenty six genus while others were included forthy three genus. The Stenogammarus genus had the normally...

  14. Distribution and biomass of macrobenthic fauna in the Chabahar Bay (North Eastern Sea of Oman)

    Nikouyan, N.; Saravi, A.
    Population density, distribution and biomass of macrobenthic fauna in Chabahar Bay were investigated from May 1995 to March 1996 on a bimonthly basis. The most abundant groups were Amphipods (21%), Polychaetes (19%), Gastropods (15.7%) and Bivalves (10.6%). Maximum (13000 individuals/m2) and minimum (4600 individuals/m2) were observed in May and July respectively. The changes in density were influenced by monsoon season of the Indian Ocean. Spatial and temporal variations in biomass were recorded for all groups separately. The lowest biomass was observed during monsoon period (July-September) with a mean of 51.5 g dry wt/m2 and the highest in permonsoon period (March-May)...

  15. Ecological study of zooplankton communities in the Persian Gulf Martyrs Lake (Chitgar-Tehran) and the first report of the freshwater jellyfish Craspedacusta sp. (Cnidaria, Limnomedusae) in Iran

    Bagheri, S.; Sabkara, J.; Yousefzad, E.; Zahmatkesh, Y.
    This study focused on zooplankton structure, biodiversity, relationship between a biotic parameters and zooplankton variation, and trophy state of the Persian Gulf Martyrs Lake (Chitgar-Tehran). Based on the lake condition, samples were collected by Juday net at the 5 stations between 2013 and 2014. This study identified 36 zooplankton taxa comprised of Arthropoda (6 genus), Protozoa (6 genus), Rotatoria (20 genus), Nematoda (1 genus), Gastrotricha (2 genus) and Oligochaeta (1 genus). Furthermore, the first record of the freshwater jellyfish Craspedacusta sp. in Iran, with size group of 15-20 mm in diameter in September is reported in the Chitgar lake. The...

  16. Water quality assessment of the Zayandehroud Lake using WQI index

    Khalaji, M.; Ebrahimi, E.; Hashemenejad, H.; Motaghe, E.; Asadola, S.
    Biological and ecological studies of water resources play an important role in both researches and scientific studies. The most important step for this study is identifying the characteristics of the ecosystem, living organisms and environmental factors. In recent years, Water quality evaluation, especially drinkable water, became both important and essential for reduction in quality and quantity of them. Lakes and ponds always being under attention as the most important resources for drinking and agricultural purposes. To improve efficiency of uses of the water resources, we need appropriate methods to determine quality of them. Investigate the quality of the Zayandeh roud...

  17. Study on the effect of salinity changes on growth, biomass, and chlorophyll a and carotenoid pigments of microalgae Nannochloropsis oculata

    Rahimisuruee, M.; Rohani Ghadikolaei, K.; Mohammadizade, F.
    In this study the effect of different salinities on growth, biomass and pigments of Chlorophyll a and Carotenoid were tested to determine an appropriate salinity to produce maximum growth, biomass and carotenoids of microalgae (N.oculat).Therefore, the 2-liter flask contains microalga under different levels of salinities (20, 25, 32, 35, 50 ppt), and under laboratory conditions( temperature 25-22 ° C, PH. 8, and light period of 12 h light and 12 h darkness) were cultured for 14 days. The results of present study indicate that The maximum growth of microalgae (72.63×106 cell ml–1) and the maximum specific growth rate of microalgae...

  18. Estimation of primary production in the Mahshahr creeks (Khozestan-Persian Gulf) using field and remote sensing data

    Mosavi Dehmoedi, L.; Savari, A.; Dostshenas, B.; Mohamad Asgari, H.; Abassi, A.
    Primary production is an important indicator of aquatic ecological systems. The spatial and temporal pattern of OPP is helpful for global climate change study. In this study the spatial and temporal variability of primary productivity in the 3 creeks of Northwest of Persian Gulf from Feb 2014 to Nov 2014 was estimated using a VGPM primary productivity model and insitu measurement. Single Peak of primary productivity appeared in April (0.356 gc/m2/d) and fall in July (0.217gc/m2/d). From the correlation analysis, we found that observed primary production has a good relationship with measured primary production (p<0.01, R2=0.60). A linear regression was...

  19. Phytoplankton population structure of the Anzali wetland (2010 and 2011)

    Fallahi, M.; Makaremi, M.; Khatib, S.
    Phytoplankton groups are very important producers in the Anzali wetland having a significant role in the quality and need to be constantly studied in term of their sequence and density. This survey was conducted at 6 stations between March 2011 and February 2012. According to the results, 67 different genera (22 Bacillariophyta, 26 Chlorophyta, 9 Cyanobacteria, 5 Cryptophyta, 1 Euglenophyta, 2 Chrysophyta, 1Dinoflgellata and 1 Xanthophyta) were identified. Most observed in Sorkhankol and Karkan stations with the annual average of 24.4±5.6 and 20.4± 5.4 cells/ liter respectively. The Bacillariophyta particularly Cyclotella was dominant in all of the stations, but high...

  20. Dispersal, biodiversity and morphological characteristics of pelagic fish larvae in coastal waters of Hengam Island (Strait of Hormoz)

    Chashti, N.; Sakhaei, N.; Dustshenas, B.; Archangi, B.
    This research have been conducted to investigate pelagic fish larval disperse, biodiversity and morphological features around Hengam Island. The island is located in south coast of Qeshm island in Strait of Hormoz. The bottom of vicinity water of Hengam Island is covered with coral reefs. Sampling carried out from late winter 2012 until late autumn using oblique sampling with 300 µm mesh plankton net. Fish larvae individuals were collected from near bottom to surface with three replicates from six selected sampling sites around the island. A total number of 6832 fish larvae were obtained from several families including Atherinidae, Carangidae,...

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