Micro structure analysis of the ovaries of common carp, Cyprinus carpio L. inhabiting a polluted reservoir, Umiam in Meghalaya, India.

The study uses microscopy to analyze damage caused to the ovaries of a fresh water fish, Cyprinus carpio L., owing to its exposure to municipal wastes in a polluted reservoir, Umiam in Meghalaya, India. Histological analysis of the ovary showed atretic oocytes, detached ovarian wall, detached follicular linings, and necrosis of nuclei. Scanning electron microscopy revealed deformed oocytes with a rough and distorted surface. Transmission electron microscopy showed a poorly developed chorion, presence of relatively less electron-dense materials as compared with control, multinucleation in some cells surrounding the oocytes, and distorted and condensed mitochondria. The importance of microscopy in its different forms in analyzing histological, surface microstructural and fine structural damage to fish ovaries in response to environmental pollution owing to municipal wastes and city garbage is discussed with the help of available literature.

Microscopy and microanalysis of hematological parameters in common carp, Cyprinus carpio, inhabiting a polluted lake in North East India.

Optical and scanning electron microscopy (SEM) of red blood cells (RBCs) of common carp, Cyprinus carpio, inhabiting a polluted lake in Northeast India revealed a number of abnormalities. About 7% of the RBC showed the presence of a micronucleus, besides the presence of some bi-nucleated and abnormally shaped nuclei. RBCs, white blood cells, and hemoglobin content were found to be reduced significantly as compared to the control. SEM showed the presence of spherocytes, early stages of echinocytes, cytoplasmic blebbing, erythrocytes with contraction from one side, abnormal shape of erythrocytes (hexagonal/pentagonal/tetragonal), development of lobopodial projections, cell rupture, membrane internalization, and formation of ring-shaped RBC. Energy dispersive X-ray spectroscopy (EDS) showed the presence of a considerable percentage of silicon and lead in erythrocytes of the fish collected from the polluted lake, in contrast to a negligible concentration of the two elements in control fish. Significance of the study in relation to fish health in a polluted body of water and the importance of SEM, EDS, and light microscopy in utilizing hematological parameters as pollution indicators are discussed.

An electron microscopic analysis on the ultra structural abnormalities in sperm of the common carp Cyprinus carpio L. inhabiting a polluted lake, Umiam (Meghalaya, India).

The present communication reports the ultra structural abnormalities in sperm of a fish species Cyprinus carpio inhabiting a polluted lake, Umiam in North-East India. Transmission electron microscopy (TEM) revealed absence of differentiation between head and midpiece (neck) of some sperm while scanning electron microscopy (SEM) showed some sperm tails with highly reduced length and some sperm with folded tail. Abnormal shape of some sperm head was also revealed by Scanning electron microscopy. Detachment of membrane from some parts of the sperm head and an outward expansion of the same was observed from Transmission electron micrographs of transverse section of sperm head. The well developed mitochondria surrounding the cytoplasmic channel in the sperm tail, as observed in control were found to be drastically disorganized in fish inhabiting the polluted lake. The study suggests that the fish C. carpio inhabiting the polluted lake Umiam is under severe stress as far as its male reproductive system is concerned. The study further suggests that Electron microscopic approach is extremely important in the assessment of adverse effects of environmental pollution on fish tissue. Microsc. Res. Tech. 2011. © 2011 Wiley Periodicals, Inc.