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.     

X-Irradiation and thyroid activity in a teleost,Mystus vittatus (Bloch)

Zusammenfassung Eine niedrige Dosis Röntgenstrahlen führt zu einer mässigen Steigerung der Radiojodaufnahme in der Schilddrüse vonMystus vittatus, während mit steigender Röntgendosis die Radiojodaufnahme gehemmt werden konnte.     

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.     

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.     

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.     

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.     

Action of insulin on the glycogen content of liver and muscle of the murrel,Ophicephalus striatus (Bloch)

Résumé Des doses variées d'insuline administrées à l'Ophicephalus striatus ont augmenté la quantité de glycogène du foie et des muscles. Dans le foie, les doses étant fortes (40 IU et 60 IU), la quantité normale de glycogène a presque quadruplé et elle a plus que septuplé dans les muscles. Le mécanisme possible présidant à l'action de l'insuline est aussi discuté.     

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.     

Effect of starvation on the blood ofOphiocephalus punctatus (Bloch)

Summary During starvation the values of RBC, WBC counts, Hb content and packed cell volume declined. After 15, 21 and 27 days of starvation little fluctuation was noted but major fluctuation was recorded after 33 days of starvation in all the above parameters.Thanks are due to CSIR, New Delhi, for financial assistance.     

Pinealectomy inhibits stimulation of testicular development by long photoperiods in a hamster (Phodopus sungorus)

Zusammenfassung Beim HamsterPhodopus sungorus verhinderte Pinealektomie die durch lange Photoperioden bewirkte Beschleunigung der Entwicklung von Hoden und Anhangsdrüsen. Die Befunde zeigen, dass die Epiphyse nicht ausschliesslich antigonadotroph wirkt, sondern auch an der progonadotrophen Wirkung langer Photoperioden beteiligt ist.     

Effect of organophosphate pesticide Sumithion (Fenitrothion) on some aspects of carbohydrate metabolism in a freshwater fish,Sarotherodon (Tilapia)mossambicus (Peters)

Summary A lethal (Lc₅₀/48 h — 6 mg/l) concentration of the organophosphate (OP) pesticide Sumithion increased blood glucose levels and phosphorylase activity, but hepatic glycogen registered a fall which indicated that the observed hyperglycemia was due to breakdown of hepatic glycogen.This work was supported by UGC grant to R.R.