International Journal of Aquatic Biology
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Cadmium induced histopathology in the olfactory epithelium of a snakehead fish, Channa punctatus (Bloch)
Full text linkHistopathology on the olfactory organ of a snakehead fish, Channa punctatus (Bloch, 1793) were assessed after exposing the fish to 2.5 mg/L and 5mg/L of CdCl2 for 15 days, 30 days and 45 days. Cellular organization of the epithelium was affected severely with degeneration of sensory and supporting cells and hyperplasia of basal cells and mucous cells. Mucous cell proliferation indicates the upregulation of mucous secretion to protect the epithelium from toxic effect of cadmium. The olfactory epithelium was endowed with the multipotent basal cells which differentiate into sensory cells, supporting cells and other cell types of the epithelium during normal cells turn over and in the event of cell death. However, due to cadmium exposure proliferating basal cells failed to differentiate into normal cells and the undifferentiated proliferated cell formed lump and intraepithelial lesion altering the composition of the entire epithelium. Present study indicates that in prolonged exposure to cadmium chloride olfactory functions of the fish might be impaired due to loss of all sensory cells
Body shape changes during the early development of the Beluga (Huso huso)
Full text linkEarly body shape changes of beluga sturgeon were studied using landmark-based geometric morphometric approach to recognize its allometric growth pattern. Sampling was done from hatching up to 50 days post hatching (DPH). Left side of specimens were photographed using digital camera and nine landmark points were digitized on two-dimensional images. Total length (TI) was measured using the software ImageJ. To study of the body shape changes during early development, the mean procrustes distance between all specimens of same age, for all age groups, was calculated. The scores of relative warp analysis (RW) were used as descriptors for the variation in shape. RW analysis revealed a sharp body shape change during early ontogeny on 18 DPH. Growth trajectory was computed by plotting RW against TL. The inflection point of body shape corresponds to a TL of 23.3 mm (18 DPH). Results showed that ontogenetic shape changes encompassed a pre-inflection shape changes, which included the elongation of the head and tail regions i.e. positive allometric growth pattern and post-inflection shape changes, with a nearly isometric growth pattern
Length-weight and length-length relationships, condition factors and optimal length of some fish species from the Persian Gulf and Oman Sea
Full text linkLength-weight relationships (LWRs), relative condition factor (Krel), relative weight (Wr) and optimal length (Lopt) were calculated for five important commercial fishes from Iranian waters of the Persian Gulf and Oman Sea. Samples were collected from 2011 and December 2012 in 11 stations in three Iranian provinces (Hormuzgan, Khozestan and Sistan and baluchestan) using trawl and gillnets. Also, length-length relationships (LLRs) for Pampus argenteus and Scomberomorus commerson were computed. The values of the exponent b in the length-weight relationship ranged from 2.593 for S. commerson to 2.995 for P. argenteus. Krel varied between 1.01 ± 0.08 for Parastromateus niger and 1.06 ± 0.41 for P. argenteus. Also, Wr ranged from 59.12 ± 47.74% for S. commerson to 107.78 ± 107.29% for Eleutheronema tetradactylum. The Lopt were calculated for all five species. A negative allometric growth was found in S. commerson, while other four species (E. tetradactylum, Otolithes ruber, P. niger and P. argenteus) had isometric growth. The length-weight and length-length relationships presented here are for the first time in the Iranian coastal waters of the Persian Gulf and Oman Sea, which can provide a basis for fisheries management
Studies on reproductive biology of Mystus tengara (Ham.-Buch., 1822), a freshwater catfish of West Bengal, India
Full text linkStudies on reproductive biology are essential to assess culture potential of a fish species. Mystus tengara is a popular food fish as well as preferred as an ornamental fish in West Bengal. Till date detailed report on reproductive biology of this fish species in the agro-climatic context of West Bengal is lacking. Therefore, the present work was aimed to study the detailed reproductive biology of Mystus tengara with an emphasis on sex ratio, length at first sexual maturity, cycle of gonadal maturation and spawning periodicity using standard methods. Results of the study revealed female dominance of the species over male in the population. However, the males showed earlier maturation than females. Five gonadal maturity stages namely immature, maturing, mature, ripe and spent were identified both for female and male fishes. Monthly study of gonadosomatic index (GSI), condition factor and mean ova diameter revealed that the breeding season for this fish species extended from May to September with a single spawning month in July. Total spawning behaviour along with synchronous oocytes development was also observed in this fish species
An investigation on morphology, age and growth of the Caspian Sea Kilka (Clupeonella cultriventris) in Babolsar, southern Caspian Sea
Full text linkIn this study, 160 fishes were randomly collected from commercial catch by a cone net in Babolsar Port from January to October 2010. The biological features of specimens were measured. 2+ years old fishes made the dominant age group with 33.75% and 1+ and 5+ years old had the least frequency (8.75%). Relationship between length and weight indicated negative allometric growth pattern (b=2.581). The Von-Bertalanffy growth parameters were calculated as L¥=131.57 mm, k=0.26 and t0=-1.02. Growth performance index was 1.66 and the total mortality (Z), natural (M) and fishing (F) mortality coefficients were 0.9 year, 0.43 and 0.47, respectively. The exploitation ratio (E) was calculated as 0.52
Sialic acid specific lectins from Episesarma tetragonum (Decapoda, Grapsidae): isolation, purification and characterization
Full text linkTwo sialic acid specific lectins Episesarma tetragonum agglutinin–1 and 2 were purified from the hemolymph of the Mangrove crab, Episesarma tetragonum. The major lectin was purified using CNBr-activated sepharose 4B conjugated to fetuin. N-acetyl glucosamine containing buffer was used for elution. The hemagglutination activity of purified lectin was inhibited by glycoproteins containing Siaα, 2-3Galβ, 1-4 GlcNAc linkages. On SDS-PAGE, the molecular weight of calcium dependent lectin was observed to be 70 kDa. Lectin had the maximum activity at a wide range of pH (6.5 – 9.5) and temperature (0 - 40 °C). The physicochemical characteristics of the minor agglutinin showed that its hemagglutinating activity was calcium dependent, optimum at pH 8 – 9.5 and temperature 0 – 37 °C. The only potent inhibitor of minor lectin was bovine submaxillary mucin. An attempt was also made to purify minor lectin by affinity chromatography using bovine submaxillary mucin coupled to CNBr-activated sepharose 4B column. The lectin was eluted with elution buffer containing ethylene diamine tetra acetate. Strong inhibition of purified minor lectin by bovine submaxillary mucin and non-inhibitory action of de-O-acetylated bovine submaxillary mucin suggested that the lectin was O-acetyl sialic acid specific
Effect of dietary free L-Lysine on growth performance and muscle composition of Beluga Huso huso (Linnaeus 1785) juveniles
Full text linkEffect of dietary free L-Lysine on growth, food intake, and muscle composition of beluga juveniles were investigated over 6 weeks. Control diet lysine content was 2.1% of dry matter (4.4% of dietary protein). Three experimental diets were prepared by adding lysine (0.5, 1 and 1.5%) to control diet to obtain diets containing 2.6, 3.1 and 3.6% of dry matter lysine (corresponding to 5.5, 6.6 and 7.6 of dietary protein). Fish were fed 2.6% of dry matter lysine showed significantly higher final weight, weight gain and SGR and lower FCR compared to other treatments. There was no significant change in food intake and survival between treatments. Lysine supplementation resulted significantly in increase and decrease in muscle protein and lipid, respectively. Dietary lysine has no effect on muscle ash and moisture content. Results showed that lysine supplementation had no significant effect on food intake in beluga juveniles. It seems that dietary lysine level of 2.6% of dry matter (corresponding to 5.5% of dietary protein) is suitable for growth of beluga juveniles
Microsatellite variation and genetic structure of common carp (Cyprinus carpio) populations in Gomishan bay and Gorganroud River (Southeast of the Caspian Sea)
Full text linkCommon carp (Cyprinus carpio) population has been declined in the Caspian Sea in the recent years, mainly due to human manipulation. This valuable species needs to be protected in the Caspian Sea. Considering the commercial value of common carp, its rehabilitation program has been established. In the present study, 8 microsatellite loci were used to assess genetic variation and population structure of common carp in Gomishan bay (GB) and Gorganroud River (GR). These two regions are the most important habitat of common carp. Mean actual (Na) and expected (Ne) alleles numbers were 15.12 and 11.35 for GB and GR, respectively. Mean observed (Ho) and expected (He) heterozygocity were 0.99 and 0.90 for GB and GR, respectively. Results, also, showed that all investigated loci were polymorphic. Twelve out of 16 tested locusí—region combinations showed significant deviation from Hardy-Weinberg equilibrium (HWE) which could be mainly due to increase in He. FST index was found to be 0.011. Hence, AMOVA showed that observed variation was related to within population (99%) as well as between populations (1%). According to the results, it is suggested that studied populations have a great allelic richness and gene flow