Maintenance of thyroid activity with some steroids in hypophysectomized and gonadectomized catfish,Mystus vittatus (Bloch)

Zusammenfassung Beim amerikanischen WelsMystus vittatus (Bloch) wurde festgestellt, dass die Radiojodaufnahme der Schilddrüse nach Hypophysektomie durch Cortison und Sexualhormone wieder normalisiert werden kann.     

Effects of varied photoperiods on rhythmic activity of thyroid gland in a teleost,Mystus vittatus (bloch)

Résumé La glande tyroide duMsytus vittatus sous photoperiodes normales montre des variations cycliques saisonnières: Au cours d'un an il y eut 2 phases d'activité tyroidale augmentée et chacune fut séparée par 1 phase de repos. Sous illumination prolongée le type de variations resta identique; sauf les phases de repos furent enregistrées 2 mois plus tôt que la normale. Ce plan rythmique d'activités disparut dans une obscurité totale et l'activité tyroidale demeura a un niveau élevé toute l'année.     

Electron diffraction of the metallic elements in the pineal organ of a freshwater fish, Mystus vittatus (Bloch.)

By electron diffraction pattern the presence of metallic elements, particularly chromium-nickel, chromium phosphide, copper, aluminum-copper and zinc has been shown in the pineal organ of a freshwater teleost, M. vittatus. It is likely that their occurrence within the pineal is due to binding with the neurosecretory material fractions/ligands.     

Influence of photoperiods on the seasonal fluctuations of TSH content of the pituitary in a freshwater catfish,Mystus vittatus (Bloch)

Zusammenfassung Mystus vittatus zeigt unter natürlichen Bedingungen jahreszeitliche Variationen des TSH Gehaltes der Hypophyse. Veränderung der Lichtverhältnisse kann diesen TSH Zyklus beeinflussen: Dauerlicht verschiebt die Phasen, Dauerdunkel unterdrückt die zyklischen Veränderungen auf einen geringen Aktivitätsgrad.     

Electron diffraction of the metallic elements in the pineal organ of a freshwater fish,Mystus vittatus (Bloch.)

Summary By electron diffraction pattern the presence of metallic elements, particularly chromium-nickel, chromium phosphide, copper, aluminum-copper and zinc has been shown in the pineal organ of a freshwater teleost,M. vittatus. It is likely that their occurrence within the pineal is due to binding with the neurosecretory material fractions/ligands.The technical assistance of O.N. Srivastava and financial assistance of CSIR, India, are gratefully acknowledged.     

Histochemical localization of alkaline and acid phosphatase activities in the skin ofMystus (Mystus) vittatus Bl. (Siluriformes)

Summary An attempt has been made to localize alkaline and acid phosphatase activities in the skin ofMystus vittatus by using histochemical techniques. The alkaline phosphatase activity is found in metabolically active cells such as basal columnar cells, mucous cells and polygonal support cells. The acid phosphatase activity is intense in the outermost squamous support cells and in the basal columnar cells. These activities have been correlated with some physiological functions of the epidermis.Acknowledgment. We are thankful to P. Vishwanatham, Government College, Mhow, and Dr R.S. Shrivastava, Holkar Science College, Indore, for providing laboratory facilities and to the Council of Scientific and Industrial Research, New Delhi, for a fellowship for M.S.     

Thyroid activity in response to some gonadal steroids in methallibure-treatedHeteropneustes fossilis (Bloch)

Summary Methallibure treatment is as effective as hypophysectomy in reducing thyroid activity inH. fossilis. Sex steroids (TP and EB) administration restored thyroid activity in methallibure-treated females to normal level, but failed to elicit any response in males. This drug seems to block TSH secretion and thyroid hormone synthesis inH. fossilis.Financial assistance in the form of SRF from ICAR, New Delhi to one of us (R.B.R.), gift of methallibure from ICI Ltd., UK and TSH from NIH, USA, to T.P.S. are gratefully acknowledged.     

Acute toxicity of copper and its probable effect on thyroid of the fry ofOphiocephalus punctatus (Bloch)

Summary LC₅₀ values for 24, 48, 72, 96 and 120 h were estimated at 1.507; 1.065; 0.785; 0.607; 0.559 mg/l copper respectively for the fry ofOphiocephalus punctatus. Copper induced hyperthyroidism resulting in exopthalmos, has been reported for the first time.     

Vitellogenesis in the air breathing fish,Channa punctatus (Bloch)

Summary Two types of yolk develop in the oocyte ofChanna punctatus. The carbohydrate yolk, which develops from the material present in the ooplasm, breaks up for the use of the growing oocyte before ovulation takes place. The proteid yolk, developing from the extraoocytic material, finally crams the fully mature oocyte, perhaps to participate in the process of embryogenesis.Acknowledgments. The authors are grateful to Professor C.C. Das, for his encouragement and the laboratory facilities. The award of a U.G.C. junior fellowship to one of us (U.R.A.) by the Berhampur University is thankfully acknowledged.     

Toxicity of Temik (aldicarb) for a fresh water teleost,Barbus conchonius Hamilton

Summary The toxic effects of Temik (aldicarb) on a fresh water Himalyan lake teleost,Barbus conchonius were investigated in hard and soft water. The 48-, 72- and 96-h TL_m-values in mg/l were 8.99, 2.39 and 2.42 respectively in the hard-water test and 3.30, 0.62 and 0.46 in the soft-water test. The toxicity of Temik toB. conchonius increases many fold in soft water.One of us (S. C. P.) is grateful to U. G. C., for the award of a senior research fellowship.     

Increase in acid phosphatase activity during fertilization of a teleost egg

Summary Acid phosphatase activity was localized at the periphery of the yolk globules in the egg of the teleost,Catostomus commersoni. In addition, a 3-fold increase in acid phosphatase activity was associated with fertilization and pronucleus formation.I thank Dr C. W. Huver for use of facilities.     

Photosensitivity of the pineal organ in the teleost,Salmo irideus (Gibbons)

Zusammenfassung Mikroelektrodenableitung der freigelegten Epiphyse der Regenbogenforelle,Salmo irideus (Gibbons), zeigt eine spontane Impulsaktivität, die bei Belichtung des Organs gehemmt wird und auch nach Entfernung der lateralen Augen bestehen bleibt. Nach Helladaptation des Pinealorgans an ein starkes Licht ist während des nachfolgenden Dunkelaufenthalts eine Empfindlichkeitszunahme um das 10⁵-fache festzustellen. Die Spektralsensitivität der Hemmung ähnelt der Absorptionskurve eines Photopigments mit Maximum bei 505 mµ.     

Thyroid activity in response to some gonadal steroids in methallibure-treated Heteropneustes fossilis (Bloch).

Methallibure treatment is as effective as hypophysectomy in reducing thyroid activity in H. fossilis. Sex steroids (TP and EB) administration restored thyroid activity in methallibure-treated females to normal level, but failed to elicit any response in males. This drug seems to block TSH secretion and thyroid hormone synthesis in H. fossilis.