• R Nagabhushanam

      Articles written in Proceedings – Animal Sciences

    • Histomorphological studies on the brain neurosecretory profile of Indian leech,Poecilobdella uiridis (Blanchard)

      R Nagabhushanam G K Kulkarni

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      The histological scrutiny of the brain ofPoecilobdella viridis revealed two types (A and B) of neurosecretory cells, which are classifiedon the basis of size, shape and tinctorial characters. A cells are spheroid, rarely pyriform, with size (cell area) varying between 608 μ to 1701 μ. Their cytoplasmic granules take violet colouration with AF and deep red with Mallory’s triple stains. B cells are elongate or oblong with a size (cell area) ranging between 516 μto 831 μ. Their cytoplasmic granules are coloured blue to violet with AF and pink with Mallory’s triple stains. Neurosecretory material staining intensity of these cells is described light microscopically.

    • Histochemistry of the ovary ofMacrobrachium kistnensis

      R Sarojini M S Mirajkar R Nagabhushanam

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      The ova ofMacrobrachium kistnensis are characterized by the presence of perinuclear glycogen spherules and peripheral proteid yolk. The ovarian epithelium is rich in neutral mucopolysaccharides. The vitellogenic oocytes filled with yolk globules and granules are rich in corbohydrates and lipids.

    • Development of the incretory organs in the eyestalk of freshwater prawn,Macrobrachium kistnensis

      M S Mirajkar R Sarojin R Nagabhushanam

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      The development of the neurosecretory cells in eyestalk is studied in zoea, juvenile and adult stages of theMacrobrachium kistnensis. In zoea, the ganglionic mass of the eyestalk compreses of three parts viz. medulla externa, medulla interna and medulla terminalis. The future sensory pore x-organ is characterized by onion bodies near medulla terminalis and a vacuole closely applied to the outer surface of the eyestalk. The monopolar giant neuron is observed in zoea. In juvenile prawn, in addition to zoeal features the sinus gland makes its appearance. At this stage, neurosecretory cells are discernible in the medulla externa and terminalis. In adults, the eyestalk presents well developed lamina ganglionaris, medulla externa ganglionic x-organ (m.e.g.x.), medulla interna ganglionic x-organ (mi.g.x.) and medulla terminalis ganglionic x-organ (m.t.g.x.).

    • Pheromonal and hormonal control of reproduction in the freshwater prawn,Macrobrachium kistnensis

      R Nagabhushanam P R Machale R Sarojini

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      In the freshwater prawnMacrobrachium kistnensis reared with males, the ovarian development occurred normally, whereas it was delayed in the absence of males. Testis and vas deferens extracts when added to the water in which females are being reared brought about normal development of ovary in comparison to those which were reared in boiled water or ‘female water’ alone. Therefore, mature males appear to be producing a pheromone which is necessary for the ovarian development of the female and the source of this might be vas deferens or testis. On the other hand, the central nervous tissue extracts stimulated vitellogenesis in oocytes. In particular, the brain extracts were more effective than those of thoracic ganglion in inducing this response. Thus, in the present study ovarian maturation and vitellogenesis appear to be under the pheromonal and hormonal controls.

    • Isolation of neurosecretory hyperglycemic hormone from the eyestalks of freshwater crab,Barytelphusa cunicularis

      R Nagabhushanam P R Machale R Sarojini

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      A procedure is described for the purification of neurosecretory hyperglycemic hormone from the eyestalks of freshwater crab,Barytelphusa cunicularis. This procedure involved a combination of gel filtration on Sephadex G-50 and a subsequent preparative polyacrylamide gel electrophoresis which revealed that hyperglycemic hormone moved faster than other proteins.

    • Tributyltin oxide induced alterations in exuvial weight and calcium content of the prawn,Caridina rajadhari

      R Nagabhushanam P S Reddy R Sarojini

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      Moulting is the predominent feature of crustaceans. Cyclic cuticle deposition and resorption of calcium from old cuticle occur in relation to the crustacean moult cycle. Prolonged exposure of the prawn,Caridina rajadhari to media containing sublethal doses (0·015, 0·020, 0·025 and 0·040 ppm) of tributyltin oxide led to an apparent increase in dry weight of exuvia as well as an increase in the total quantity of calcium. The increase in weight and calcium content of exuvia was not significant in the initial two moults whereas it was significant (P<0·05) in the third moult when exposed to minimum (0·015 ppm) dose. However significant (P<0·01) rise in both exuvial weight and calcium quantity in the first two moults and highly significant (P<0·001) in the third moult exuvia were observed when exposed to maximum (0·040 ppm) dose. The observed changes in exuvia from prawns exposed to tributyltin oxide might be due to a decrease in the resorption of the old cuticle and/or due to the inhibition of chitinolytic enzymes.

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