فهرست مطالب

International Journal of Aquatic Biology - Volume:5 Issue: 2, 2017
  • Volume:5 Issue: 2, 2017
  • تاریخ انتشار: 1396/02/02
  • تعداد عناوین: 7
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  • Ranjeet Kutty, Shahana Shamsudheen, Shafeena Ottathaikkal, Jamsheera Vallikkattil Pages 52-62
    Estuarine environments are one of the most dynamic aquatic ecosystems and serve many important functions in coastal waters. Larval fish dynamics contribute significantly to understanding the ecology of fish populations as they can indicate the spawning-stock biomass and recruitment in adult fish stocks. Initial development stages of fishes are particularly vulnerable and are influenced by physical and biological processes. Hence the present study was aimed to characterize ichthyoplankton assemblages, to evaluate environmental influence in its structure. Ponnani backwater fish larvae assemblages displayed a clear seasonal pattern presenting higher abundances and diversities during warmer months. Throughout the year there is a wide fluctuation in salinity, temperature and primary productivity in these backwaters enabling it to be classified under stressful environment for larval forms of certain economically important marine fishes. A detailed analysis made to study the interaction of selected environmental parameters with ichthyofaunal diversity in Ponnani backwater provided a clear understanding on the influence of these variables on the distribution of marine fish larvae in the region. The results of the present analysis provided a model for the prediction of larval diversity from the prevailing environmental parameters.
    Keywords: Ichthyoplankton, Assemblage, Estuary, Climate change, Ponnani
  • Shima Shahafve, Mahdi Banaee, Behzad Nematdoost Haghi, Mohammad Mohiseni Pages 63-70
    This study aimed to evaluate the effects of aflatoxin-contaminated diet on histopathological alterations of the gill, liver, kidney and intestine tissues in common carp. Fish were randomly distributed into 15 tanks, i.e. in five experimental groups; (I) control fed with normal diet without solvent and aflatoxin, (II) positive control received feed with only solvent, and (III-V) fed on diets containing 0.5, 0.7 and 1.4 mg kg-1 of aflatoxin, respectively. After 21-days, 12 fish per treatment were randomly caught, anesthetized and euthanized. Then, histological sections of the tissues were prepared. The main aflatoxicosis symptoms in the gills were fusion and disorganisation of the secondary gill lamellae, shortening of the secondary lamellae, inflammation of mucous membranes, and exfoliation of the gill epithelium. Liver of the infected fish indicated cloudy swelling of hepatocytes, cellular hypertrophy, formation of vacuoles in the cytoplasm, and necrosis of liver parenchyma. Expansion of Bowman’s space, necrosis of urinary tract, exfoliation and degeneration of the urinary tract epithelium, expansion of the urinary lumen and dilation of the urinary space were observed symptoms in the kidney. Changes in the intestine of the aflatoxin-treated fish were; expansion of goblet cells, necrosis of mucous layers, exfoliation of the mucous epithelium, and bleeding in the intestinal wall. The results indicates that feeding common carp with diets contaminated with aflatoxin, even in low concentrations (≤ 1.4 mg kg-1 feed) can cause histopathological damages and disturb their physiological balance.
    Keywords: Aflatoxicosis, Feed poisoning, Common carp, Tissue damage
  • Nasrin Hassanzadeh Pages 71-78
    Methyl paraben (MP) is widely used as a preservative in various products. It frequently enters into aquatic environment and renders potential threat to fish. The aim of this study was to evaluate reproductive toxicity of MP on zebrafish (Danio rerio) under laboratory conditions. Male zebrafish were exposed to four concentrations of MP (0.001, 0.01, 1, and 10 mg L-1) for 21 days in semi-static condition. Changes in mean length, mean weight, gonadosomatic index (GSI) and histology of testis were studied. Treatment at 0.001 to 10 mg L-1 MP had no significant effect on the survival, mean length and mean weight of fish. But, GSI decreased in a dose dependent manner and the decrease was significant in the group that received the highest dose. Histological alteration of testis consisted of general testicular atrophy, multi-nucleated gonocytes (MNGs), impaired germ cell, spermatogonial proliferation, Leydig cell hyperplasia, interstitial fibrosis and apoptosis of Sertoli cells. It was concluded that sub-chronic exposures of MP could adversely affect GSI, disrupt the histology of testis and produce estrogenic and antispermatogenic activity in male zebra fish.
    Keywords: Histopathology, Parabens, Reproductive, Toxicity
  • Bhushan Kumar Sharma, Nogen Noroh, Sumita Sharma Pages 79-94
    This study aims to assess ecosystem diversity of Rotifera of the floodplain lakes (beels) of the Brahmaputra river basin with reference to faunal diversity of the taxon in wetlands of conservation areas of India. We observed 141 rotifer species, belonging to 31 genera and 17 families, from three beels of the Dibru-Saikhowa Biosphere Reserve (DSBR) of Assam, northeast India (NEI) with high total richness (117±2 species) in individual beels. One, two and three species are new to the Oriental region, India and Assam state, respectively and 21 species are globally interesting. The diverse Lecanidae > Lepadellidae > Trichocercidae; the paucity and scarceness of Brachionidae and Brachionus spp. in particular; and rare nature of Keratella, Filinia, Asplanchna, Polyarthra, and Conochilus are salient. The monthly richness and community similarities affirmed heterogeneity in species composition in individual beels while this study exhibited overall rotifer homogeneity amongst beels. The richness followed monthly oscillations in the three beels and lacked significant variations amongst beels. The peak richness of 76 species during summer (May, 2014) from No. 11 beel is one of the richest rotifer assemblages known in single date collection from an aquatic ecosystem of South Asia. Our results explained little influence of individual abiotic factors while canonical correspondence analysis endorsed high cumulative influence of 17 abiotic factors on richness in all beels.
    Keywords: Conservation area, Composition, Distribution, Interesting taxa, Richness, Wetlands
  • W.M. Dimuthu Nilmini Wijeyaratne, Bellanthudawage Kushan Aravinda Bellanthudawa Pages 95-107
    Six sampling sites were selected to represent different land use types in the rehabilitated and non-rehabilitated areas of a recreational wetland in Sri Lanka to study the suitability of macrobenthic mollusc diversity to monitor spatial and temporal variation in physico-chemical parameters of water and shallow sediments. Individuals belonging to six families and eight species were recorded during the study. The significantly highest mean abundance (individuals) of Bithynia tentaculata and Pila globosa were recorded in sites from the rehabilitated area and there was no significant temporal variation of mollusc abundance during the study. The abundance and diversity of mollusc community showed significant spatial variations and this study identified that B. tentaculata and P. globosa can be used as possible bioindicators to detect changes in water and shallow sediment quality in tropical wetland ecosystems
    Keywords: Biomonitoring, Principal Componesnt Analysi, Diversity indices, Sri Lanka
  • Kaveh Amiri, Nader Shabanipour, Soheil Eagderi Pages 108-113
    Understanding ecological and anthropogenic drivers of fish population dynamics and achieving a sustainable yield requires detailed studies on habitat selection and spatial distribution. The objective of this study was to predict spatial density and distribution of kilka species in the southern Caspian sea in relation to satellite-derived sea surface temperature, chlorophyll-a concentration, turbidity and water depths using ordinary kriging and co-kriging geostatistical methods and introduction an appropriate potential fishing area according to the present fishing points. Three hundred and fifty fishing surveys were done in two main kilka fishing ports in the southern Caspian Sea (Anzali and Babolsar ports) from 2015 to 2016. The Geostatistical analysis showed that the co-kriging spatial interpolation method provided the best prediction of fish abundance when chlorophyll-a content was included in model.
    Keywords: Modeling, Predict catch abundance, Kilka, Caspian Sea
  • Do alien species matter? Impacts of invasions in Indian freshwater systems and challenges in management
    Murugan Muralidharan Pages 114-127
    Alongside anthropogenic activities and habitat destruction, invasions are regarded as one of the most influential components of global change. India as a growing economy and rapidly developing nation has been constantly engaged in infrastructure development which consequently has led to depletion of natural resources and declining quality of habitats aquatic systems in particular. Invasions that have established from the introductions in past during the colonial era and recently spread species are great challenges that hamper survival of aquatic resources. As of 2015, 20 plants, one mollusc and 37 fishes are known to have naturalized in Indian water bodies. Awareness on the invasive species along with detailed information on the ecosystem-wide impacts is essential for management.
    Keywords: Aquaculture, Exotics, Freshwater, Invasive species, Management challenges