32,068 research outputs found
Stable isotopic indicators of population structure and natal habitats of Asian carps threatening to invade the Great Lakes
Understanding early-life habitats is crucial for managing non-indigenous large river fishes such as silver carp that are threatening to invade the Great Lakes and may significantly impact economically valuable Great Lakes fisheries. Silver carp inhabiting the upper Illinois River directly below the electrical deterrent barrier (installed on a canal in the Chicago area that connects the Illinois River with Lake Michigan) possess the greatest potential to invade the Great Lakes. However, adult silver carp inhabiting this reach of the Illinois River may have originated from many points throughout the Mississippi River basin (e.g., Illinois River or Middle Mississippi River), and the relative importance of these potential origination locations is unknown. As such, this study was used to identify natal habitats of adult silver carp in the upper portion of the Illinois River. Based on the stable oxygen and stable carbon isotopes of otoliths (earstones) from individual fish, we have determined that silver carp inhabiting the area below the electric barrier originated from within the Illinois River itself, the Middle Mississippi River, and floodplain lakes along the lower Illinois River valley. Because of the geographically widespread points of origin for individual fish, management efforts for eradication or control of silver carp in the upper Illinois River should be directed at a similarly broad geographic scale. While potentially challenging to implement, large-scale removal of silver carp and the closely related bighead carp in the Illinois and Mississippi Rivers could greatly reduce the probability of these species breaching the electrical barriers and entering the Great Lakes
What you should know about carp: its origin, varieties, physical appearance, feeding habits
The article discusses the different varieties of carp, their origin, physical appearance and feeding habits. The species discussed are grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), catla (Catla catla), rohu (Labeo rohita), mrigal (Cirrhinus mrigala), and common carp (Cyprinus carpio)
Species interaction between carp species in polyculture system
A three months experiment was conducted to study the species interactions of two carp species in polyculture system under supplemental feeding. Four species of fishes such as silver carp (Hypophthalmichthys molitrix), mrigal (Cirrhina cirrhosus), catla (Catla catla) and common carp (Cyprinus carpio) were cultured in four different combinations each containing two species. The combination of silver carp and mrigal in treatment 1, and silver carp and common carp in treatment 2 resulted better growth and production than other two treatments of different combinations of catla and common carp, and catla and mrigal
Measurement and comparison of Iron levels and hazard quotient (HQ) on muscle of farmed and marine fishes from Khuzestan, south west of Iran
The aim of this study was to determine the concentration of iron and Hazard quotient (HQ) in muscle of four marine fishes, orange - spotted grouper (Epinephelus coioides), yellow fin sea bream (Acanthopagrus latus), tongue fishes (Cynoglossus arel), silver pomfret (Pampus argenteus) and farmed carp fish, common carp(Cyprinus carpio), grass carp (Ctenopharyngodon idella), big head carp (Aristichthys nobilis) and silver carp (Hypophthalmichthys molitrix) from Khuzestan. Farmed fish sample was prepared from the Azadegan warm water fish culture center and marine fish was prepared from fishing ports Bahrkan, Abadan and Bandar Emam. Iron concentration measured by wet digestion and atomic absorption spectrometer Perkin Elmer 4100.The results showed the average of iron level in farmed fish was 17.08± 1.21 mg/kg dry weight and in marine fish was 10.68± 3.66 mg/kg dry weight (p<0.05).The results showed that the highest iron concentrations between farmed fish muscle was on big head carp equal to 18.16mg/kg dry weight and was significantly different (p<0.05) with grass carp and the highest iron concentrations between marine fish muscle was onTongue fishequal to 15.50± 0.50mg/kg dry weight and was significantly different (p<0.05). Average hazard quotient in farmed fish was HQ=0.61and in marine fish was HQ =0.38. Hazard quotientin marine fish were in tongue fish HQ=0.55, yellow fin sea breamHQ =0. 3, Orange - spotted grouper HQ= 0.26 and silver pomfret HQ =0.41 and Hazard quotient in fish were in big head HQ=0.65, common carp HQ =0.63 grass carp HQ= 0.55and silver carp HQ =0.61. Hazard quotient in all samples was less than one and so fish nutrition no risk in terms of the amount of iron in the human body
Diversity of eukaryotic plankton of aquaculture ponds with Carassius auratus gibelio, using denaturing gradient gel electrophoresis
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 in pond 1 were significantly higher than pond 2 (p>0.05). The concentration of chlorophyll a (chl a) has no significantly difference between pond 1 and pond 2. DGGE profiles of 18S rRNA gene fragments from the two ponds revealed that the diversity of eukaryotic plankton assemblages was highly variable. 91 bands and 71 bands were detected in pond 1 and pond 2, respectively. The average Shannon–Wiener index of pond 1 was significantly higher than pond 2. Canonical correspondence analysis (CCA) revealed that temperature played a key role in the structure of the eukaryotic plankton community in both ponds, but the nutrient concentration did not affect it. Our results suggest that DGGE method is a cost-effective way to gain insight into seasonal dynamics of eukaryotic plankton communities in culture ponds, and the increase in the number of filter-feeding silver carp and bighead carp could increase the diversity of the eukaryotic plankton community
Sequence of the growth hormone (GH) gene from the silver carp (Hypophthalmichthys molitrix) and evolution of GH genes in vertebrates
The silver carp (Hypophthalmichthys molitrix) growth hormone (GH) genewas isolated and sequenced following amplification from genomic DNA by the polymerase chain reaction. The gene spans a region of approx. 2.5 kb nucleotides (nt) and consists of five exons. The sequence predicts a polypeptide of 210 amino acids (aa) including a putative signal peptide of 22 hydrophobic aa residues. The arrangement of exons and introns is identical to the GH genes of common carp, grass carp, and very similar to mammals and birds, but quite different from that for the GH genes of tilapia and salmonids. The silver carp GH gene shares a high homology at the nt and aa Ievels with those of grass carp (95.3% nt, 99.5% aa) and of common carp (81% nt, 95.7% aa)
Recruitment Sources of Invasive Bighead Carp (Hypopthalmichthys nobilis) and Silver Carp (H. molitrix) Inhabiting the Illinois River
Knowledge of natal environments and dispersal of invasive Bighead Carp (Hypopthalmichthys nobilis) and Silver Carp (H. molitrix) inhabiting the Illinois River would be valuable for directing population reduction efforts intended to supplement electrical barriers in the Chicago Sanitary and Ship Canal and limit the probability of these species invading the Great Lakes. However, the extent to which Bighead Carp and Silver Carp (collectively referred to as bigheaded carps) stocks in the Illinois River are derived from recruits that originate within the Illinois River itself versus immigrants from the Mississippi and Missouri rivers is unknown. Bigheaded carps are also known to use connected floodplain lakes during early life, but the contribution of these habitats to recruitment of Bighead and Silver carps in the Illinois River is also unknown. The aim of this study was to identify natal environment of adult bigheaded carps collected from the Illinois River during 2010-2011 using stable isotope and trace element analyses of otolith cores. Both water and otolith strontium:calcium ratios (Sr:Ca) and water and otolith oxygen isotope ratios (expressed as δ18O) were strongly correlated for known-origin bigheaded carps, consistent with other fish species. Most Bighead and Silver carps collected from the Illinois River used river channel rather than floodplain lake habitats during early life. The majority of adult Silver Carp originated in the Illinois River, although 11-39% were immigrants from the Missouri or middle Mississippi rivers. In contrast, 97% of the Bighead Carp originated in the Illinois River. Our results indicate that efforts to substantially reduce abundance of bigheaded carps in the Illinois River drainage should continue to focus on the Illinois River itself, but will likely need to be expanded to include the middle Mississippi and Missouri Rivers for sustainable control of Silver Carp
Culture of Chinese carps using anaerobic fermented cow manure (Slurry) and comparison of survival and growth factors versus traditional culture
The objective of this project is to compare growth and survival rate in Chinese carps reared under traditional culture conditions versus those reared in ponds treated with slurry (anaerobic fermented of cow manure). This experiment was conducted using two treatments one treatment using slurry and the other using cow manure plus chemical fertilizer as the control with three replicates for each. Chinese carp were stocked at the density of 2375 individuals/ha ( Silver carp 60%, Bighead 15%, common carp 17% and grass carp 8%). In this investigation common carp and grass carp were fed with formulated diets and fresh grass, respectively. The survival rate in the slurry treatment was higher than that in traditional treatment. Survival rates were 98, 100, 84 and 52 percent for silver carp, bighead, common carp and grass carp, respectively in the slurry treated ponds and 96.0, 98.3, 82.8 and 20.0% percent in the control ponds. The results showed that survival rate and yields were higher in the slurry treated ponds than that in the control. The increasing percent of yield were 13.5, 2.6, 18.4 and 85.3 in silver carp, bighead, common carp and grass carp, respectively. The survival rate for grass carp was two times higher in the slurry treatment than control. Zooplankton abundance in slurry ponds was higher than that in control, but blue-green algae density in slurry treated ponds was less than (over 50%). In general the results indicate that slurry with higher nutritional content is more effective on the survival and growth rate of fishes and also is more efficient in the proliferation of plankton in particular zooplankton. Slurry also reduces the use of chemical fertilizers
Impacts of Thai silver barb (Puntius gonionotus Bleeker) inclusion in the polyculture of carps
The impact of inclusion of Thai silver barb, Puntius gonionotus (Bleeker) in the polyculture with two major Indian carps viz., Labeo rohita, Catla catla and common carp Cyprinus carpio has been studied in seasonal ponds for 115 days. The presence of silver barb decreased the growth of Indian carps while increased that of common carp. A significantly higher (P<0.05) fish yield (1793.65 Kg/ha/yr) was observed in the four species polyculture system containing silver barb when the combined yield of all species was compared
Praziquantel (Droncit) is effective against diplostomosis of grasscarp Ctenopharyngodon idella and silver carp Hypophthalmichthys molitrix
In laboratory experiments praziquantel (Droncit) effectively destroyed metacercariae of Diplostomum spathaceum (s. l.) parasitizing the eye lens of grasscarp Ctenopharyngodon idella and silver carp Hypophthalmichthys molitrix. A single treatment with Droncit fed at a dose of 330 mg kg^-1 body mass showed 100% efficacy against metacercariae parasitizing grasscarp. A similar, complete parasiticidal efficacy was achieved when infected grasscarp and silver carp specimens were exposed to a solution containing 1 mg praziquantel l^-1 for at least 90 h. Using shorter exposures (20 min to 1 h) but elevated praziquantel doses (10 to 100 mg l^-1), some parasites survived but even here the intensity effect reached 67 to 97%
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