Adult Common Carp Cyprinus Carpio Research Articles

Light microscopic study on the absorptive cells and goblet cells in the intestine of adult common carp Cyprinus carpio

The purpose of this study was to describe of some histological structures and histochemical features of the absorptive cells and goblet cells in intestine of common carp. In this study, Fifteen adult male common carp were catching alive from the AL-Forat river, with age about (7 - 12) months and mean of their weight was (2100 ± 81 g) and mean standard length was (50.4 ± 3.1 cm), immediately after death.Incision was made through the midventral line of the fish just from cranial to the anus to expose the intestine, specimens of intestine were taken and washed with (0.9 %) normal saline solution. Ten samples were obtained from different regions of each portion of the intestine (anterior, middle and posterior), fixed by either 10% neutral buffered formalin or Bouin’s solution approximately 24 hours at room temperature and then treated by routine histological processing. The stains were used, Hematoxylin and Eosin, periodic acid Schiff, Alcian blue pH 2.5, and Combinated Alcian blue PH 2.5 plus periodic acid Schiff. The Mean number, height and width of mucosal folds were measured and counts of goblet cells in the mucosal folds of each portion of the intestine. The results showed that the intestinal epithelium is simple columnar, the enterocytes were tall columnar cells with brush border; goblet cells were ovoid, located between the enterocytes. The folds composed of the entire thickness of the mucosa, mean number, height and width of the mucosal folds were few in posterior portion of intestine compare with that in other portions. The anterior portion of the intestine has largest number of mucosal folds, while has less number of goblet cells compare to middle and posterior portions of the intestine. The epithelial cells stained red-purple by periodic acid Schiff stain with Alcian blue, the goblet cells were take positive reaction with periodic acid Schiff stain, and with Alcian blue plus periodic acid Schiff, while negative with only Alcian blue stain. Glycoprotein staining intensity varied from very weak to moderate, whereby the presence of neutral, acidic and sulphatedglycoconjugates. In conclusion, numbers of goblet cells were observed to be increased towards posterior portion of intestine required as lubricant for fecal expulsion, and reversed relation between number of the folds and goblet cells.

Heat and chemical treatments in adult Cyprinus carpio (Pisces cypriniformes) rapidly produce sterile gonads

Several options have been proposed for eradication of germ cells (GCs) in mammals such as treatment with cytotoxic drugs, irradiation, cold ischemia and hyperthermic treatment. Some of these methods have been also tried in fish but conditions for complete sterilisation of gonads have not been established. Here, we report the production of sterile adult common carp Cyprinus carpio in 10 weeks by the heat and chemical treatments. The cytotoxic drug busulfan (40mg/kg) was intraperitoneally injected into the animals at 2-week intervals (5 doses in total), and they were maintained in water at 38°C between Weeks 1 and 10. The effectiveness of the treatments was assessed using gonadal index, histology, and vasa gene expression. At the end of Week 10, very severe gonadal degeneration was observed in fish treated with the heat–chemical combination, and 100% of male and female fish were devoid of endogenous GCs. The average levels of vasa transcript were 0.01±0.005 and 0.02±0.016 for males and females, respectively. By contrast, high temperature alone caused minor gonadal degeneration and the gene transcript were 0.59±0.131 for male and 0.62±0.13 for female. In Week 20, after the recovery period of 10 weeks at 25°C, the gonadal germ cell did not recover from the sterile condition in any of the sampled individuals. The change in colouration of gonads was an additional useful index of the degree of gonadal sterility.

Common carp Cyprinus carpio responses to sub-chronic exposure to perfluorooctanoic acid.

Perfluorooctanoic acid (PFOA) is an important and diffuse perfluorinated alkylated substance, but knowledge of the toxicological effects of this endocrine disrupter in fish is limited. Adult common carp Cyprinus carpio, L. were exposed to 200ng/l (a concentration reported in impacted aquatic ecosystems) and 2mg/l PFOA solutions in a flow-through system for 56days to determine tissue accumulation and histological alterations of the primary target organs. PFOA was extracted from blood, gill, liver, muscle, kidney, gonad, and brain by an ion-pairing liquid extraction procedure and quantified using high performance liquid chromatography with electrospray ionization tandem mass spectrometry. The limit of detection (LOD) was 0.4ng/g wet weight (ww). PFOA was not detectable in unexposed fish or in fish exposed to 200ng/l, but was >LOD in most samples of carp exposed to 2mg/l. Mean PFOA concentration ranged from 0.5 to 65ng/g ww, depending on the tissue, with highest levels in the blood and liver. There were no significant differences in condition factor, hepato-somatic index, or gonado-somatic index among the fish of the three groups. Histological, histochemical, and immunohistochemical staining was performed on sections of liver and gonad. Occurrence of atretic oocytes and a paucity of spermatozoa were documented in carp treated with 2mg/l PFOA. Exposed fish did not show gross hepatic anomalies, but there was enhancement of hepatocytes in proliferation (positive to anti-PCNA antibody) compared to controls.

Identification and comparison of gonadal transcripts of testis and ovary of adult common carp Cyprinus carpio using suppression subtractive hybridization

The limited number of gonad-specific and gonad-related genes that have been identified in fish represents a major obstacle in the study of fish gonad development and sex differentiation. In common carp Cyprinus carpio from China's Yellow River, the ovary and testis differ in volume and weight in adult fish of the same age. Comparing sperm, egg, and somatic cell transcripts in this carp may provide insight into the mechanisms of its gonad development and sex differentiation. In the present work, gene expression patterns in the carp ovary and testis were compared using suppression subtractive hybridization. Two bidirectional subtracted complementary DNA (cDNA) libraries were analyzed in parallel using testis or ovary as testers. Eighteen nonredundant clones were identified in the male library, including 15 known cDNAs. The expression patterns of selected genes in testis and ovary were analyzed using reverse transcriptase polymerase chain reaction. Tektin-1, GAPDS, FGFIBP, IGFBP-5, and an unknown gene from the Ccmg4 clone were observed to be expressed only in testis. GSDF, BMI1b, Wt1a, and an unknown gene from the Ccme2 clone were expressed at higher levels in testis than in ovary at sexual maturity. Thirty functional expressed sequence tags (ESTs) were identified in 43 sequenced clones in the female library, including 28 known cDNAs, one uncharacterized cDNA (EST clone), and one novel sequence. Eight identified ESTs showed significant differences in expression between the testis and the ovary. ZP3C and Psmb2 were expressed exclusively in ovary, whereas the expression levels of IFIPGL-1, Setd6, ATP-6, CDC45, AIF-1, and an unknown gene from the Ccfh2 clone were more strongly expressed in ovary than in testis. In addition, the expression of ZP3C, Wt1a, and Setd6 was analyzed in male and female gonads, heart, liver, kidney, and brain. ZP3C was expressed only in ovary. Setd6 expression was significantly stronger in female tissues than that in the male, except in the liver, and Wt1a expression showed sexual dimorphism in the kidney and liver. Results suggest that these genes could play key roles during carp growth, both in the gonad and other tissues. The results provide a resource for further investigation of molecular mechanisms responsible for gonad development and sex differentiation in Yellow River common carp.

Backwater Immigration by Fishes through a Water Control Structure: Implications for Connectivity and Restoration

AbstractRecent efforts to reduce sediment loading in large‐river backwaters have relied on inexpensive low‐maintenance structures that promote river–backwater connectivity. How these structures influence ichthyofauna is not understood. We quantified the distribution of fishes through a stop‐log structure installed during the Swan Lake habitat restoration project on the lower Illinois River. Modified hoop nets were systematically fished simultaneously in a two‐dimensional 3 vertical × 3 horizontal grid of net locations to capture fish as they immigrated into the lake through the structure. Catches were dominated by gizzard shad Dorosoma cepedianum and freshwater drum Aplodinotus grunniens. Adult freshwater drum, adult common carp Cyprinus carpio, and juvenile silver carp Hypophthalmichthys molitrix exhibited an affinity for the lower two‐thirds of the water column. Lengths of freshwater drum increased with depth, particularly during the spring. Common carp catch rates were highest during spring, whereas those for silver carp were highest during fall and winter. Closure of the bottom two‐thirds of the lower Swan Lake water control structure could reduce immigration of exotic and undesirable species into the backwater; their recruitment associated with the lake could be affected accordingly. The water control structure does not appear to have negatively affected lateral fish movement. However, habitat quality and availability probably determine seasonal patterns in backwater use. In systems where exotic species are abundant, lateral connectivity may need to be assessed from a cost‐benefit perspective, specifically as it pertains to maintaining habitat availability for indigenous fishes versus limiting habitat availability for introduced species.