Md. Ahmad Ali

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This paper presents the results of a comparative investigation of the retinas of two Hiodontids, the goldeye (Hiodon alosoides) and the Mooneye (H. tergisus) employing light and electron microscopy, cell isolation techniques as well as microspectrophotometry. Contrary to the observations of previous workers these species possess a duplex retina. The(More)
  • M A Ali
  • 1975
Published information concerning the influence of temperature in the physiological range (0-40 degrees) on various aspects of the visual process in invertebrates and vertebrates (poikilotherms and homeotherms) is reviewed. Bleaching and regeneration of scotopic and photopic pigments is influenced by temperature; so is the porphyropsin-rhodopsin ratio in(More)
Correlation of visual pigment content and photoreceptor cell structure is studied in the cichlid fish Nannacara anomala the retina of which is characterized by simple organization of the outer plexiform layer. The visual cell types consist of long and bulky rods and only two types of cones: equal double cones and short single cones. Both types of cones(More)
A simple and cost effective spectrophotometric method is described for the determination of flupenthixol dihydrochloride in pure form and in pharmaceutical formulations. The drug was highly soluble in methanol so it was selected as the solvent system for the drug. This ensured adequate drug solubility and maximum assay sensitivity. The linearity range for(More)
  • M A Ali
  • 1981
Vertebrates have, through the process of evolution, adapted to their photic environment. This is well manifested in the retinal adaptations to various habitats. Although all vertebrates are considered, emphasis is placed on fishes because they form about 50% of the vertebrate species. In addition, they occupy a wide range of habitats, thus retinal(More)
Unilateral exposure of dark-adapted fishes indicates that the exposed eye is only partly in a light-adapted state in so far as the position of the epithelial pigment and cones is concerned. This does not occur in epiphysectomized fishes indicating a possible role of the epiphysis. On the basis of available evidence, the nature of the epiphysis role is(More)
The scotopic visual pigments of three percids from Quebec waters, viz. the yellow perch (Perca flavescens), the walleye (Stizostedion vitreum) and the sauger (S. canadense), were studied in situ using a microspectrophotometer-computer complex. The difference spectra show that the three fishes possess a porphyropsin whose lambda max. is at 530 nm in the(More)
The morphology of the retinas of the goldeye Hiodon alosoides (fam. Hiodontidae), the brook trout Salvelinus fontinalis (fam. Salmonidae), the yellow perch Perca flavescens and the walleye Stizostedion vitreum (fam. Percidae) was studied by SEM. Semi-thin plastic sections of the same retinas were also examined for comparison. Contrary to observation of(More)
This paper presents the results of an investigation concerned with the effects of long-term hypophysectomy on the retinomotor responses of the euryhaline killifish, Fundulus heteroclitus: 1. The eye of hypophysectomised Fundulus heteroclitus responds to light and dark in the same manner as that of intact controls: the retina is not in a state of permanent(More)