Adult Cyprinus Carpio Research Articles

Effects of Pollution on the Haematology of Cyprinus carpio Inhabiting two Government Sponsored Fish Ponds in East Khasi Hills District, Meghalaya, India

Adult Cyprinus carpio were collected from two government sponsored fish ponds located at Fish Dale and Laitkyrhong, East Khasi Hills District, Meghalaya, India. The effects of pollutants on haematological parameters of Cyprinus carpio were studied. The results showed a decline in RBC and WBC count and haemoglobin content in fishes collected from Laitkyrhong. Micronucleus assaywas carried out following standard protocols and observations were made using Olympus, BX- 53 image analyser, CellSens Standard (software). Analysis showed a number of micronucleus and nuclear abnormalities of the erythrocytes of Cyprinus carpio from Laitkyrhong as compared to fishes from Fish Dale. Scanning Electron Microscopy study revealed swollen erythrocytes called spherocytes, ruptured erythrocytes and crenations at the erythrocyte membranes while the control erythrocytes showed normal features. The Energy Dispersive X-ray Spectroscopic analysis was by INCA-7582 (Oxford) Energy Dispersive X-ray microanalyser equipped with a Si (Li) high resolution detector attached to the scanning electron microscope, JSM-6360 (Jeol). Differences in the EDS spectra of RBCs from control, Laitkyrhong and Fish Dale fishes were observed to be in terms of Silicon (Si), Aluminium (Al) and Titanium (Ti) were absent in the control sample. The presence of silicon in erythrocytes of fishes inhabiting Fish Dale and Laitkyrhong area suggests that silicon may be the main factor for the various deformities in the haematological parameters of Cyprinus carpio. The deformities observed may affect the growth and survival of these fishes. Therefore, there is a constant need to check the flow of polluted waters in the rearing ponds especially during the rainy seasons. The present study suggests that haematological study may serve as a tool in determining the health of the fish and the type of environment in which it lives.

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.

Distributional Ecology and Behavioral Thermoregulation of Fishes in Relation to Heated Effluent from a Power Plant at Lake Monona, Wisconsin

Cooling water for a 220-megawatt power plant is pumped from 5 m beneath Lake Mononaˈs surface, heated about 10 C, and discharged into the littoral zone. Maximum temperatures in the effluent-outfall area approach 35 C in summer and 14 C in winter; unheated parts of the littoral zone rarely exceed 29 C. To assess distributional responses of fishes to operation of the power plant, the outfall area and two reference areas were electrofished on 30 dates between 8 August 1968 and 21 August 1969. Some fishes avoided the outfall area; these were Perca flavescens, Cottus bairdi, subadult Morone mississippiensis, and subadult Ictalurus melas. Others were occasionally or usually concentrated in the outfall area relative to reference areas—Lepisosteus osseus, adult Cyprinus carpio, adult M. mississippiensis, young Lepomis gibbosus, L. macrochirus, and Micropterus salmoides. The tendency for fish of a given species and size to concentrate in or avoid the outfall area generally did not reverse from season to season or from day to night. Any differences in growth rate of young fishes among outfall and reference areas were obscured by size-dependent movements of the fish. In August 1970, body temperature of fishes in the outfall area varied with species and time of day. During afternoon, median temperatures of Cyprinus carpio, Lepomis gibbosus, L. macrochirus, and Micropterus salmoides were higher than 29 C, while those of Morone mississippiensis, Ambloplites rupestris, Pomoxis nigromaculatus, and Perca flavescens were lower than 29 C. At night, only Lepisosteus osseus and C. carpio had median body temperatures higher than 29 C. Young Lepomis macrochirus collected during summer 1970 from the outfall area had estimated acclimation temperatures between 29.4 and 31.3 C, even though temperatures between 25 and 36 C were available. To have had acclimations between 29.4 and 31.3 C, the fish must have avoided exposure to temperatures higher than about 31.5 C. This conclusion agreed substantially with the distribution of body temperatures of young L. macrochirus; the highest body temperature among 31 specimens was 31.8 C. Temperatures at which fishes lived in the outfall area during summer 1970 were positively correlated (p < 0.01) with the degree to which they were concentrated in the outfall area during the two previous summers. The strength of the correlation argued that, during summer, temperature was the primary factor governing not only distribution of fishes within the outfall area, but also the abundances of fishes in the outfall area relative to unheated parts of the littoral zone. Moreover, integration of field and laboratory results suggested that fishes were distributed within the outfall area according to their different temperature preferenda. Preferred temperatures of six Lake Monona fishes were measured by allowing each of several specimens to behaviorally regulate the temperature of its tank. Midpoint of the preferred temperature range agreed well with the median body temperature recorded in the outfall area during afternoon (considering, in the case of Perca flavescens, that temperatures below 26.5 C were not available in the outfall area): Cyprinus carpio, 31.8 C (laboratory), 30.6 C (field); Lepomis macrochirus, 30.3, 29.4; Micropterus salmoides, 29.1, 29.7; Pomoxis nigromaculatus, 28.3, 28.3; A. rupestris, 27.3, 27.5; and Perca flavescens, 23.4, 27.1. In other laboratory experiments, Lepomis macrochirus and Perca flavescens were required to partition time between an environment with preferred temperature and an environment with food but either warmer or cooler than the preferred temperature. Each species made forays for food into water with extreme temperatures. However, neither laboratory nor field results suggested that thermoregulatory behavior was overridden by feeding behavior, even though zooplanktonic food was more abundant in the outfall area than in unheated parts of the littoral zone.