Studies on the effect of monochrotophos (an organophosphate) on changes in bimodal oxygen consumption in an air breathing climbing, pereh Anabas testudineus (Bloch) have been made. Control group of fishes relies more on aquatic gas exchange obtaining 61. 5% of 02 from water where as only 38. 5% oxygen is obtained from air under normal bimodal condition. Exposure of fishes to sublethal concentration (15mg/l) of monohit caused decrease in total 02 uptake but increased aerial respiration as compared to control. Drop in aquatic respiration ranged from 45. 5-56. 0% while increase in aerial respiration ranged from 9. 6-68.9% as compared to control. The reasons for such changes in O2 uptake has been discussed in this paper.
Studies on the effect of ovariodectomy (OD) on changes in few physiological profiles (such as oxygen uptake and heamatological make up) have been made in a snake headed murrel fish, Channa striatus (Bloch). OD brought significant decrease in R.B.C. counts, Hb content, PCV, M. CH. C. and Oxygen consumption as compared to control (Sham operated). The reason for such changes has been discussed in this paper.
Effect of some hormones and pharmacological drugs on oxygen uptake and equivalent energy utilization (E.E. U) has been made in an air breathing fish, Rita rita (Ham. ). The value for oxygen uptake (m/o/h) and E.E.U (K. cal/h) in control (45.01r1.5g) were 4.512 m/o/h anol 0.0216 K.caI/h, respectively. Treatment of hydrocortisone, adrenaline, progesterone and thiouracil bring about significant decrease while the treatment of testosterone and L-thyroxine bring about significant increase in Oxygen uptake and E. E. U. in fresh water fish, Rita rita (Ham.)
Studies on cyclic activities of thyroid gland in relation to environmental factors were made in the spiny mud eel obligate water breather fish, Macrognathus aculeatum (Bloch). The activities of thyroid gland showed para/lesim with water temperature and natural photoperiod but from the regression analysis of the data, it was evident that the effect of photoperiod on thyroid activity is more pronounced as compared to water temperature. The maximum thyroid activity coincides well with the breeding phase of the animal. The details have been discussed in this paper.
Marked seasonal variations in the body composition (especial/y lipid and water content) were observed in Heteropneustes fossilis (Bloch). The lipid and water contents were inversely proportional to each other. Fattening in this fish is closely associated with gonadal cycle and physical activity of the animal. The maximum lipid content was recorded in the winter months when the gonads were regressing or in regressed condition while minimum was recorded in the breeding season (summer months).
Studies on seasonal variations in aquatic, aerial and total oxygen uptake in a fresh water facultative air breathig fish, Clarias batrachus (Linn. ) were made for a period of twelve months. In this fish aquatic, aerial and total 0, uptake ranged respectively between 4 1. 8-61. 2; 6. 2-30. 8 and 49. 0-91. 0 cc/kg/h. The percent 0, uptake through aerial route were lowest (12.157%) in January and highest (33.846%) in June. The aquatic/aerial ratio was lowest (1.945) in June and highest (7.226) in January. The reason for such variations have been discussed in this paper.
In the present work an attempt has been made to study the correlation, if any, between the cyclic changes in oxygen consumption (Vo?) and different haematological parameters in an air breathing fish, Anabas testudineus (Bloch). Two peaks of activity were marked in both the parameters. A positive correlation occurs between RBC/VOZ. Hb/Vo2 and PCV/Vo2 in both the sexes. The increase in VO2 seems to be more associated with the increase in RBC counts than with the increase in Hb content and PCV. Cyclic changes in Vo2 and different blood parameters show parallelism and a physiological balance exists between these two parameters.
Studies on the effect of sublethal concentration of Herboclin (weedicide; 0.30 mg/l) and phosalone (an organophosphate pesticide, 20. Omg/I) were made to evaluate the changes in total proteins (wet weight) content in few tissues (namely -Testes, ovary, liver and muscles) in an air breathing murrel fish, Channa gachua (Ham. ). The exposure of fishes to sublethal concentration of both Herboclin and phosalone caused significant decrease in total protein content as compared to control. The effect was more pronounced in phosalone treatment as compared to control. The reason for such changes has been discussed in this paper.
Studies on water, protein, lipid content and calorific values (k.cal/g) in different tissues such as muscle, liver, kidney, ovary and brain have been made in a fresh water Indian major carps Labeo calbasu (Ham. ). Protein, lipid content and calorific values were found maximum in liver while the brain contained maximum water content (88. 15%) and minimum amount of protein content (9.3010.84%). The details have been discussed in this paper.
The effect of sub/ethal dose (0.3mg/l) of an organochlorine pesticide, Lindane on impairment of pituitary gland has been studied in a fresh water teleostean fish, Mystus vittatus (Bloch). The treatment of Lindane for 90 days in the fish caused significant decrease in the almost all the types of cells (two types of both each acidophils and cyanophils and one type of chromophobes) of pars proximal dista/is as compared to control. The reason for such changes have been discussed in this paper.
In the present work an attempt was made to assess the acute toxicity of Merit Alpha (an organochlorine pesticide) and its impact on behavioural response of a fresh water obligate air breathing fish, Channa gachua (Ham. ). The LCSO values for 24, 48, 72 and 96 hrs exposure at 29. Gt 1. 0° for MeritAIpha exposed fishes were 0. 0058, 0. 0042, 0.0032 and 0.0020 mg/l respectively. The safe concentration of MeritAIpha was 0.0007 mg/I under the same experimental condition. The mean values of opercular beating decreased gradually with the increasing concentration of Merit Alpha. The behavioural responses of the fish (such as fast opercular beatings for half an hour to one hour, loss of balance, erratic swimming, secretion of copious amount of mucus on the body etc.) of the fish was gross/y dependent on concentration and length of exposure of MeritAIpha.
Cyclic activity of thyroid gland and gonad were studied in an air breathing fish, Heteropneustes fossilis to establish, if a relationship exists between them. These glands showed parallelism in their activity. Bilateral oraviectomy brought significant decrease in thyroid activity in ovariectomized animals (P<0.05). Correlation coefficient and coefficient of determination were high showing interrelationship of these two glands in this fish.
The present paper deals with the effect of certain pesticides (namely Dithane M-45 and Metacid 50) on aquatic, aerial and total oxygen consumption besides equivalent energy utilization (E. E. U.) in a fresh water facultative air breathing siluroid fish, Clarias batrachus (Linn. ). The exposure of fishes to both the pesticides at different concentrations caused significant decrease in total oxygen uptake but on the otherhand significant increase in O, uptake through aerial route was noticed. The reason for such changes have been discussed in this paper.
The present paper deals with the effect of hormones and pharmacological agents on the activity of gonads in Anabas testudineus at two different temperatures and different periods of breeding cycles. In males at high temperature 31°C, in May when the testes were matured and full of sperms, the treatment of ovocyclin, duogynon forte and testosterone propionate (T.P.) brings about significant decrease in 68! as compared to control indicating that these agents play an important role in the release of milt but at low temperature (22°C, in January) when the testes were in regressed condition except TP. all the agents failed to exhibit any significant change in the testicular activity. Fertyl in males and ovocyclin in females has no effect on the gonadal activity. At high temperature (31°C) the treatment of lutocyclin, fertyl and duogynon forte brings about significant decrease in G8! in females indicating that these agents are concerned with the maturation and finally ovulation of eggs but at low temperature except fertyl all the the agents failed to bring any significant change in GSI. The effect of different agents seems to be temperature dependent.
Studies on the effect of Phosalone (an organophosphate pesticide) on histochemical changes in gills were made in a snake headed murre/ fish, Channa gachua (Ham. ). In the gills of control fish – Bromophenol blue test (for general protein), Alcian blue test (for acid mucosubstances) and PAS test (for carbohydrate substances) exhibited strong reaction both in the cartilagenous part of the gill arch and in the primary gill lame/lae. In phosalone treated fishes, their gills showed reduction in staining property (showing weak reaction) though there was difference in the staining intensities in acidophil cells, mucous cells, epithelial cells and central column of secondary gill lame/lae. The reason for such changes have been discussed in this paper.
The effect of two agrochemicals namely urea and ammonium sulphate on changes in bioenergetic mode/ling has been studied in a fresh water air breathing snake headed murrel, Channa punctatus (Bloch). This study indicated that both the above noted agrochemicals caused appreciable decrease in food efficiency, daily individual growth increment (g/fish/day) and energy value for production of new tissue (P) but on the otherhand the maintenance energy expenditure (i.e. F+U+R) in experimental animals increased as compared to control. The reason for such changes has been discussed in this paper.
The results of an experimental study to find out whether or not photoperiod has a definite effect on the life of l to Vinstar nymphs ( till emergence of adults) of Dysdercus koenigii by exposing them to sunlight fora specified period ( 10-14h) at temperature range of 25°-32° C and 75-85% RH were found to be as follows (i) Nymphal duration decreases and there is a significant reduction in % moulting of nymphs of all instars with increase in period of exposure to light, (ii) There is no correlation between growth ( change in weight and % moulting, (iii) There is also no correlation between growth and % moulting with increasing duration of exposure to light(iv). There is no significant difference in moulting time of male and female Vinstar nymphsat the time of adult emergence (v) % growth is higher in male than in female adults at the time of emergence from V instar nymphs .(vi) there is a significant positive correlation between % growth and duration of exposure to light, and (vii) absolute growth in weight from linstar nymph to adult is roughly 9000% in male and 12000% in female . All these results indicate a definite effect of photoperiod on the life of nymphs of D.koenlgii.