M. Selvanayagam

Histopathology of lambda-cyhalothrin on tissues (gill, kidney, liver and intestine) of Cirrhinus mrigala

The histopathology of lambda-cyhalothrin, a synthetic pyrethroid pesticide, on the gill, liver, intestine and kidney tissues in fish, mrigal (Cirrhinus mrigala), which is one of Indian major carp species were determined by light microscopy. The fish were experimentally exposed to sub-lethal concentrations (0.3ppb and 0.6ppb) of lambda-cyhalothrin for 10 days. Tissues were normal in the control group. Epithelial hyperplasia, aneurism, epithelial necrosis, desquamation, epithelial lifting, oedema, shortening of secondary lamellae and lamellar fusion were observed in gill tissues exposed to lambda-cyhalothrin. Necrosis of tubular epithelium, cloudy swelling of epithelial cells of renal tubules, narrowing of the tubular lumen, contraction of the glomerulus and expansion of space inside the Bowmans capsule were observed in the kidney tissues of fish after exposure. Hepatic lesions in fish exposed to lambda-cyhalothrin were characterized by hypertrophy of hepatocytes, cloudy degeneration, congestion, karyolysis, karyohexis, dilatation of sinusoids and focal necrosis. The intestinal lesions included infiltration of eosinophils into the lamina propria and atrophy of epithelial cells. The present study proves its toxic potential in terms of the damages induced by lambda-cyhalothrin in organ level. In natural condition lambda-cyhalothrin will be less than the present study, but continuous usage of the pesticide might lead to the concentration that was used in the experimental condition.

The effects of fenvalerate on different tissues of freshwater fish Cirrhinus mrigala

The histopathological changes of fenvalerate on the gill, kidney, liver and intestine tissues of the Cirrhinus mrigala were determined by light microscopy. The fish were exposed to two sub-lethal concentrations of fenvalerate (1.5–3.0 ppb). The most common gill changes at all concentrations of fenvalerate were epithelial hyperplasia, epithelial necrosis, desquamation and lamellar fusion. Besides, epithelial lifting, oedema, swelling at the tips of secondary lamellae and curling of secondary lamellae were other histopathological changes. Necrosis of tubular epithelium, pycnotic nuclei in the hematopoietic tissue, hypertrophied epithelial cells of renal tubules, narrowing of the tubular lumen, expansion of space inside the Bowmans capsule and contraction of the glomerulus were observed in kidney tissues of fish. Hepatic lesions in the liver tissues of fish exposed to fenvalerate were characterized by congestion, cloudy swelling of hepatocytes and focal necrosis. Atrophy of epithelial cells, necrosis of epithelial cells, desquamation of mucosal epithelium and infiltration of lymphocytes into the lamina propria were detected in intestine tissues of fish after exposure to fenvalerate.

Histopathological changes in the gill and liver tissues of freshwater fish, Cirrhinus mrigala exposed to dichlorvos

The histopathological effects of dichlorvos, an organophosphate pesticide, on the gill and liver tissues in Cirrhinus mrigala were determined by light microscopy. The fishes were exposed to sublethal concentrations (0.91 and 1.82 ppm) of dichlorvos for 10 days with parallel untreated control. No histopathological effects were observed in control group. Hyperplasia, desquamation, and necrosis of epithelial, epithelial lifting, oedema, lamellar fusion, collapsed secondary lamellae, curling of secondary lamellae and aneurism in the secondary lamellae were observed in gill tissues exposed to dichlorvos. Hepatic lesions in the liver tissues of fishes exposed to dichlorvos were characterized by cloudy swelling of hepatocytes, congestion, vacuolar degeneration, karyolysis, karyohexis, dilation of sinusoids and nuclear hypertrophy.

Biofouling and its Control in Seawater Cooled Power Plant Cooling Water System - A Review

Biofouling may be defined as the attachment and subsequent growth of a community of usually visible plants and animals on manmade structures exposed to seawater environment. Man has long been aware of this problem. In the fourth century B.C., Aristotle is reported to have stated that small “fish” (barnacles) were able to slow down ships. Fouling of ship hulls, navigational buoys, underwater equipment, seawater piping systems, industrial or municipal intakes, beach well structures, oil rigs and allied structures has often been reported. In the past few decades, the list of affected structures has expanded. Now, reports are common regarding the biofouling that affects Ocean Thermal Energy Conversion (OTEC) plants, offshore platforms, moored oceanographic instruments and nuclear and other submarines. The impact of biofouling on sea front structures is staggering. Ships show a 10% higher fuel consumption caused by increased drag and frictional resistance resulting from hull and propeller fouling. Water lines lose their carrying capacity and speed of flow owing to biofouling growth along pipe systems. The heat exchanger performance declines due to attachment of biofoulants. Many marine organisms themselves face the constant problem of being colonized and overgrown by fouling organisms. Immobile plants and animals are generally exposed to biofouling and consequent loss of species and community assemblages. Biofouling also promotes corrosion of materials. The money and material needed for fouling protection measures are indeed exorbitant. It is estimated that the marine industry incurs an expenditure of 10 billion sterling pounds a year to combat the situations arising from biofouling worldwide (Satpathy, 1990). A lot of research effort has been devoted to understand the fundamental ecology and biology of fouling environments, organisms and communities in diverse settings. The huge requirement of cooling water as well as accrescent demand on the freshwater has led to the natural choice for locating power plants in the coastal sites where water is available in copious amount at relatively cheap rate. For example, a 500 MW (e) nuclear power plant uses about 30 m3sec-1 of cooling water for extracting heat from the condenser 11

Levels of Transaminases, Alkaline Phosphatase, and Protein in Tissues of Clarias gariepienus Fingerlings Exposed to Sublethal Concentrations of Cadmium Chloride

The freshwater fish, Clarias gariepienus fingerlings, were exposed to sublethal concentrations (1.7 and 3.4 mg/L) of cadmium chloride for 12 days. Aspartate aminotransferase (AAT), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and total protein levels were assayed in the gill, brain, and muscle of the fish at regular intervals of 6 and 12 days. The activities of AAT, ALT, and ALP of the treated fishes increased significantly in all the tissues compared with the control fish. Protein level in all the tissues showed a significant decrease in comparison to unexposed controls throughout the experimental periods. These results revealed that cadmium chloride effects the intermediary metabolism of C. gariepienus fingerlings and that the assayed enzymes can work as good biomarkers of contamination.

Scanning electron microscopy study of the gills, scales and erythrocytes of Anabas testudineus upon exposure to chlorpyrifos

The present study was undertaken to assess the toxicity of sublethal concentrations (125, 250, and 375 µg L−1) of chlorpyrifos on Anabas testudineus for 21 days. The morphological changes on the gills, scales, and erythrocytes of A. testudineus were observed using scanning electron microscopy. Gill alterations included highly active mucous cells, epithelial hyperplasia, and fusion of secondary lamellae. The scales showed damaged lepidonts. Oozed out cytoplasmic content and lobopodial projections were observed in the erythrocytes after exposure to chlorpyrifos.

A new species of the genus Scolopsis Cuvier, 1830 (Perciformes: Nemipteridae) from southern India and Sri Lanka

Scolopsis igcarensis, a new species of monocle bream (family Nemipteridae) from the coastal waters of southern India and Sri Lanka is described. The species is distinguished from other species of the genus Scolopsis by a combination of the following characters: scales on top of head reaching forward to between anterior nostril and snout tip; lower margin of eye below the line from snout tip to upper pectoral fin base; a bony ridge below eye; a white band from behind eye to level of end of dorsal fin base.

First Record of Eleven Reef Inhabiting Fishes from Tamil Nadu Coast of India, Bay of Bengal

Kalpakkam coast is an important strategic region reflecting the general diversity of Tamil Nadu (TN) coastal waters. In a recent inventory of fish survey conducted along this coast, we discovered 316 coastal fishes, of which >150 are reef fishes. The present paper describes the report of eleven reef-associated fishes new to the TN coast of Bay of Bengal viz. Torpedo sinuspersici Olfers, Himantura gerrardi (Gray), Gymnothorax meleagris (Shaw), Scorpaenodes guamensis (Quoy & Gaimard), Seriola rivoliana Valenciennes, Caesio cuning (Bloch), Nemipterus zysron (Bleeker), Parascolopsis eriomma (Jordan & Richardson), Abudefduf sordidus (Forsskal), Istiblennius edentulus (Forster & Schneider) and Canthigaster solandri (Richardson); out of which four (Gymnothorax meleagris (Shaw), Abudefduf sordidus (Forsskal), Istiblennius edentulus (Forster & Schneider) and Canthigaster solandri (Richardson)) are new to the Bay of Bengal coast of Indian mainland.

First record and range-extension of bigscale jawfish, Opistognathus macrolepis (Perciformes: Opistognathidae), from Indian Ocean

A specimen of bigscale jawfish, Opistognathus macrolepis (Perciformes: Opistognathidae) was collected from the travelling water screen of Madras Atomic Power Station pump house, located at Kalpakkam, south-east coast of India. Opistognathus macrolepis was previously known only from central west Pacific, from the Gulfs of Thailand and Carpentaria, Australia. The present study reports the first record of its occurrence in the Indian Ocean from the east coast of India and constitutes a new addition to the Indian coastal ichthyofauna.

New records of four reef-associated fishes from east coast of India

First records of: viper moray, Enchelynassa canina (Quoy et Gaimard, 1824); v ermiculated blenny, Entomacrodus vermiculatus (Valenciennes, 1836); cardinalfish, Apogon fleurieu (Lacepede, 1802); and orange- lined cardinalfish, Archamia fucata (Cantor, 1849) in the waters along the east coast of India are herewith docu- mented. This record increases the knowledge on the richness of the Indian marine reef-associated fauna and may suggest a range extension of the geographical distribution of the mentioned species from the western Indian waters t o east coast of India.