Papers by Reginald Victor
The freshwater ostracods (Crustacea: Ostracoda) of India
… Sound Technology in …, Jan 1, 2006
Rapid development in the Al Jabal Al Akhdar region of northern Oman is exerting pressure on water... more Rapid development in the Al Jabal Al Akhdar region of northern Oman is exerting pressure on water resources. Water quality and water use efficiency are the two most important management issues. Engineering measures to enhance water use efficiency have not produced the desired outcome due to poor water quality caused by eutrophication of reservoirs resulting from the input of nutrients in water primarily by animal feces. Consequently water in the reservoirs is under-utilized and groundwater faces the prospect of overexploitation. Management strategies are needed to tackle water quantity and quality issues in a sustainable manner. Water quality assessments and monitoring programs are valuable tools in formulating policies on proper water resources management. A research project is underway now at Sultan Qaboos University, Oman to investigate issues relating to biodiversity conservation and sustainable development of the area. The research project which started in 2004 will conclude in 2007. Water quality assessments are being done through a comprehensive survey and in-depth look at two aquatic systems affected by environmental impacts relating to health, eutrophication and pollution. Based on the study, monitoring strategies will be developed. Some sustainable management strategies will be recommended for implementation. It is expected that the research results will provide the foundation for the conservation of water resources and strategies for water use efficiency in the Jabal Akhdar region.
Fish communities of a stretch of river affected by urban disturbance in Nigeria
Tropical Zoology, 1993
ABSTRACT
Stress due to starvation is not an uncommon phenomenon in fresh-and brackish water fish living in... more Stress due to starvation is not an uncommon phenomenon in fresh-and brackish water fish living in arid environments. This study, a part of a larger investigation on the effects of stress due to starvation on the organ systems of Aphanius dispar, a cyprinodont fish in Oman, reports on the histopathological changes in the liver, using light and transmission electron microscopy. The hepatocytes showed structural and ultrastructural changes in response to 24, 48, 72 and 96 hours of starvation. The hepatocytes of the starved fish groups were characterized by a reduction in the size of their cells and their nuclei, chromatin condensation, loss of stored glycogen, large lipid droplets, wide intercellular spaces and the variable sizes of their mitochondria. Swirls of smooth endoplasmic reticulum (SER) were seen in some of the starved fishes, which may indicate their involvement in lipid metabolism and the breakdown of glycogen. This paper makes a further contribution to the understanding of the physiology of fish in arid zones.
… Sound Technology in …, Aug 29, 2006
Rapid development in the Al Jabal Al Akhdar region of northern Oman is exerting pressure on water... more Rapid development in the Al Jabal Al Akhdar region of northern Oman is exerting pressure on water resources. Water quality and water use efficiency are the two most important management issues. Engineering measures to enhance water use efficiency have not produced the desired outcome due to poor water quality caused by eutrophication of reservoirs resulting from the input of nutrients in water primarily by animal feces. Consequently water in the reservoirs is under-utilized and groundwater faces the prospect ...
Scientific reports, Jan 11, 2017
Cave-dwelling taxa often share the same phenotypic modifications like absence of eyes and pigment... more Cave-dwelling taxa often share the same phenotypic modifications like absence of eyes and pigmentation. These "troglomorphic characters" are expressed in the populations of Garra barreimiae from the Al Hoota Cave and nearby Hoti Pit in Northern Oman. Surface morphotypes of this cyprinid species are common throughout the distribution area. Very rarely individuals with intermediate phenotypes can be found. In the present study, potential gene flow between cave and surface populations was tested and population structure within five sampling sites was assessed. Overall, 213 individuals were genotyped at 18 microsatellite loci. We found that the cave populations have lower genetic diversity and are clearly isolated from the surface populations, which seem to be sporadically in contact with each other. The results indicate a recent genetic bottleneck in the cave populations. Thus, it can be assumed that during climatic changes the connection between cave and surface water bodies...
Occurrence of Cyprinotus-Fluviatilis Furtos, 1933 (Cyprididae-Ostracoda) in Southern-India
The effects of the pesticide temephos, at different concentrations, on the liver of Aphanius disp... more The effects of the pesticide temephos, at different concentrations, on the liver of Aphanius dispar, (Rüppell 1828) a cyprinodont fish, have been described. The changes in the liver tissue after exposure to 1 ppm, 5 ppm, 10 ppm and 25 ppm concentrations of temephos have been presented. Light and transmission electron microscopy showed that the degeneration of the liver cells commenced after exposure to 1 ppm and steadily progressed to show maximum changes at 25 ppm. Histopathological changes included the dilation of sinusoids, an increase in the number of lipid droplets and cytoplasmic vacuolation, pyknosis of the nuclei and focal necrosis. These results falsify the claim that temephos is a non-systemic poison.
Fish diversity of a West African river
Aphanius A. dispar (Rüppell 1828), is widely distributed cyprinodont fish in fresh and brackish w... more Aphanius A. dispar (Rüppell 1828), is widely distributed cyprinodont fish in fresh and brackish waters of the Middle East. It is capable of coping with a variety of difficult environmental conditions. It can adapt to various ranges of habitats that differ in water chemistry, temperature and stream flow. It can live in a wide range of salinity including marine water (Haas, 1982).
On the use of biotechnology for biodiversity conservation in arid countries with special reference to Oman
International Journal of Environmental Studies, 2013
Comparative anatomy and histology of the digestive tracts of two sympatric species of freshwater ... more Comparative anatomy and histology of the digestive tracts of two sympatric species of freshwater fish, Aphanius dispar (Cyprinodontidae) and Garra barreimiae (Cyprinidae) are studied. Morphometric measurements of alimentary canal such as length and the number and height of rugae in sections have been made for both species. Relationships between these morphometric characters and the total length of fish have been evaluated. The ratio between the length of alimentary canal and total length of fish in both species reflects their feeding habits. Histology of the 'stomach' and 'intestine' of these two species as shown by light microscopy has been described and compared. Results of this study are used to discuss the query whether these species have true stomachs.
Some aspects of the ecology of Macrobrachium macrobrachion Herklots, 1851 (Crustacea; Decapoda; Natantia) in the brackish water zone of Benin River at Koko, Southern Nigeria.
West African Journal of Applied Ecology, , 2005
Copper tolerance to germination in Mesquite, a potential tree species for restoring mined-lands in Oman.
Journal of Agricultural, Food and Environmental Sciences, 2007
Zoology in the Middle east, 2009
The Ring-necked Parakeet, Psittacula krameri, an invasive bird species, first appeared in Oman in... more The Ring-necked Parakeet, Psittacula krameri, an invasive bird species, first appeared in Oman in 1950 but apparently died out and was not seen again until 1965, when it was reintroduced, probably through the escape or release of captive birds. From then on the species has gradually spread to its present distributional range that includes the Musandam Peninsula, all of the northern Batinah coast, the capital area of Muscat, occasional inland towns, and the area around Salalah in southern Oman. Its introduction to Masirah Island appears to have failed to establish a breeding population. The number of sightings of parakeets in Oman has increased from one per year in the late 1960's to over 65 per year in 2001-2002. Despite the sightings of a few large flocks, flock size has remained fairly small, increasing from a mean of 1-2 individuals in the late 1960's and early 1970's to a mean of 7-8 for most years between 1985 and 2002. To date, the parakeets have been observed in areas that are inhabited by humans and in areas of agricultural development. Thus, the spread of this species within Oman is strongly linked to human activities, probably due to the increased availability of food in such areas. This species has the potential to be a serious pest in Oman consuming cash crops, particularly dates and grains. .
Effects of pesticide temephos on the gills of Aphanius dispar (Pisces: Cyprinodontidae). 43:29-38.
Tissue and Cell, 2011
Opportunistic pathogens relative to physicochemical factors in water storage tanks.
Journal of Water and Health,, 2011
Opportunistic pathogens relative to physicochemical factors in water storage tanks.
Journal of Water and Health,, 2011
Effects of deltamethrin on the gills of the Aphanius dispar: a microscopic study.
Tissue and Cell, 2012
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Papers by Reginald Victor