Haematological assessment of the effects of the anaesthetic MS 222 in natural and neutralized form in three freshwater fish species: intraspecies differences

The effects of different concentrations of natural MS 222 and neutralized MS 222 were studied on the haematology of Cyprinus carpio, Sarotherodon mossambicus and Salmo gairdneri . As judged from the results, MS 222, which is acidic in nature, produced haemo-concentration effects in all species studied, being least in the trout followed by carp and Sarotherodon mossambicus . These differences are ascribed to acid-base regulatory functions and metabolic activities of the fish species investigated. The use of neutralized MS 222 improved the haematological profiles markedly and resulted in stabilization of acid-base parameters and red blood cells sizes and numbers. Haemoconcentration effects, however, still persisted. Trout were found to be more susceptible to the stress of MS 222 anaesthesia than carp and Sarotherodon mossambicus .     

Cells with radiating vesicles in different fish species

A study was made of the ultrastructure of cells with radiating vesicles from the head kidney of different fish species: Atlantic salmon Salmo salar L., carp Cyprinus carpio L., roach Rutilus rutilus (L.), bream Abramis brama (L.), high-body pickarel Spicara staris (L.), long-striped wrasse Symphodus tinca (L.), and from spleen of the rainbow trout Salmo gairdneri Richardson, and the tilapia Sarotherodon mossambicus Peters. A disposition of vesicles around centrioles was characteristics of all the investigated cells. Some differences were marked in the fine structure of vesicles.     

Biochemical polymorphisms in South African freshwater fish. Isoenzyme patterns in fish of the families Cyprinidae and Salmonidae

Isoenzyme patterns were studied in local populations of the carp ( Cyprinus carpio ) and the bream ( Sarotherodon mossambicus ) of the Cyprinid family. and in the trout ( Sabno giardneri ) of the family Salmonidae. Homogenates of heart muscle extracts were used in the identification of PGI. NADP-IDH. PGM and 6-PGD.
Polymorphisms found and gene frequencies obtained are discussed separately for each enzyme and species or population.
In the bream, variation was found only at the PGI locus. In the carp only the PGM locus was polymorphic whereas both PGM and IDH showed variation in the trout. The variation at the PGM locus in the trout cannot support the three locus model suggested elsewhere and clearly indicates a single locus for the mo-nomeric enzyme.
The large variety of NADP-IDH types in trout not only illucidates the complexity of this locus but confirms a disomic mode of inheritance. Genetic differences in the trout populations could be related to possible advantages for management purposes.     

Biochemical polymorphisms in South African freshwater fish. Isoenzyme patterns in fish of the families Cyprinidae and Salmonidae

Isoenzyme patterns were studied in local populations of the carp (Cyprinus carpio) and the bream (Sarotherodon mossambicus) of the Cyprinid family, and in the trout (Salmo giardneri) of the family Salmonidae. Homogenates of heart muscle extracts were used in the identification of PGI, NADP-IDH, PGM and 6-PGD. Polymorphisms found and gene frequencies obtained are discussed separately for each enzyme and species or population. In the bream, variation was found only at the PGI locus. In the carp only the PGM locus was polymorphic whereas both PGM and IDH showed variation in the trout. The variation at the PGM locus in the trout cannot support the three locus model suggested elsewhere and clearly indicates a single locus for the monomeric enzyme. The large variety of NADP-IDH types in trout not only illucidates the complexity of this locus but confirms a disomic mode of inheritance. Genetic differences in the trout populations could be related to possible advantages for management purposes.     

THE INFLUENCE OF TEMPERATURE ON THE SURVIVAL OF SEVERAL SPECIES OF FISH IN LOW TENSIONS OF DISSOLVED OXYGEN

The resistance to low tensions of dissolved oxygen over periods ranging from less than a day to a week was determined for rainbow trout ( Salmo gairdnerii Richardson), perch ( Perca fluviatilis L.), roach ( Rutilus rutilus (L.)), and mirror carp, a domestic form of the common carp ( Cyprinus carpio L.) at 10°, 16° and 20°C., tench ( Tinea tinea (L.)) at 10° and 16°C., dace ( Leuciscus leuciscus (L.)) at 16° and 20°C., chub ( Squalius cephalus (L.)) at 20°C., and bleak ( Alburnus alburnus (L.)) at 16°C.
At each temperature period of survival decreased with fall in oxygen tension.
Rise in temperature between 10° and 20°C. reduced resistance to lack of oxygen of all species except rainbow trout, in which there was no significant difference between resistance at 16° and 20°C. Rise in temperature between 10° and 16°C. did, however, lower resistance considerably.
Tench were the most resistant to lack of oxygen and, in general, trout were the most susceptible. At 20°C. mirror carp required a higher tension of oxygen to enable them to survive for a week than did rainbow trout, but for shorter periods could withstand much lower tensions than rainbow trout; at 10° and 16°C. their resistance was intermediate between that of tench and rainbow trout.     

Haematological assessment of the effects of the anaesthetic MS 222 in natural and neutralized form in three freshwater fish species: interspecies differences

Interspecies haematological differences to MS 222 and neutralized MS 222 anaesthesia were investigated in Sarotherodon mossambicus, Cyprinus carpio and Salmo gairdneri acclimated under identical laboratory conditions. Anaesthesia with MS 222 resulted in a 'chemical stress' in all fish, as was evident from changes in the haematological profiles of the animals. Such species specific variations in the haematology persisted throughout the whole experiment protocol which employed different concentrations of the anaesthetic. The use of neutralized MS 222, whereby aquarium water quality remained unchanged, improved the haematological profile. Possible reasons for the interspecies differences observed are discussed.     

Effects of acute heat exposure on respiratory metabolism and blood glucose in freshwater fishes, Prochilodus scrofa (curimbatá) and Cyprinus carpio (carp) acclimatized to tropical winter

Routine oxygen consumption and blood glucose were determined from freshwater fishes, Prochilodus scrofa and Cyprinus carpio, exposed at high temperatures for 1 hr. Prochilodus scrofa had a significantly higher rate of oxygen consumption at 30 degrees C than at 25 degrees C, and carp higher at 25 degrees C than at 30 degrees C. Blood glucose was significantly higher for Cyprinus carpio than for Prochilodus scrofa at 25 and 30 degrees C; however, after exposure to these temperatures for 1 hr blood glucose did not change significantly for both species. The results suggest that these interspecific variations may be linked to the differences between native and foreign fishes and their way of life.     

Haematological assessment of generally used freshwater fish blood anticoagulants

Heparin injection B.P., containing 0·5% phenol as preservative, disodium ethylenediamine tetra-acetate (EDTA), trisodium citrate (TSC) and ammonium potassium oxalate (APO) were compared as anticoagulants for routine haematological investigations in Cyprinus carpio and Sarotherodon mossambicus . The acidic nature and haemolytic effects of EDTA and APO render them unsuitable for use with fish blood. TSC was required in higher concentrations (than heparin) for effective anticoagulation and this was undesirable for the determination of blood pH and pCO2 and certain other parameters. Several important interspecies differences in the reactions towards the anticoagulants are also reported. In general, heparin proved to be the anticoagulant of choice, although unsuitable for some assays.     

Learning from unsuccessful radio tagging of common carp in a Namibian reservoir

Radio tagged common carp Cyprinus carpio in a Namibian reservoir, where this species has been introduced, experienced 100% mortality or tag loss (  n  = 13) with surgically implanted transmitters and 100% survival (  n  = 5) with externally attached transmitters at water temperatures of 24–25° C. It seems that the negative effects of the tagging were greater for surgical implantation than for external attachment. The body shape of common carp make them well suited for external tagging, and this tagging method is recommended for common carp studies at high water temperatures or under other stressful conditions.     

Haematological assessment of the effects of the anaesthetic MS 222 in natural and neutralized form in three fresh water fish species: haemoglobin electrophoresis, ATP levels and corpuscular fragility curves

The effects of MS 222 and neutralized MS 222 anaesthesia on haemoglobin electrophoresis, erythrocyte adenosine triphosphate (ATP) levels and corpuscular fragility curves were studied in Cyprinus carpio, Sarotherodon mossambicus and Salmo gairdneri . Haemoglobin electrophoresis showed no significant intra-species differences in the percentage composition of the various fractions for any concentration of MS 222 and neutralized MS 222 used. Significant interspecies differences were, however, still observed. ATP levels showed intra and interspecies differences ascribed to the response of the fish species to MS 222-induced stress and not to actual changes in erythrocyte ATP concentrations. Differences were also observed in corpuscular fragility curves for all three species when using MS 222 or neutralized MS 222 compared to curves obtained without the use of the anaesthetic, but the mechanisms involved are not clear.     

Temperature induced metabolic costs in carp, Cyprinus carpio L., during warm and cold acclimatization

The oxygen consumption of 6 carps was measured in a flow-through respirometer when water temperature was reduced from 23 to 7°C and increased from 23 to 33°C as well as from 11 to 32°C. The metabolic reaction of Cyprinus carpio L. was assessed at 3 levels: standard, routine and spontaneous. The Standard Metabolic Rate increased and the Q₁₀ decreased with rising temperatures. A quadratic relation was established between metabolic rates and temperature level. The enery exenditure above Standard Metabolic Rate induced by temperature changes was 6.65 ± 1.97 kJ kg^-0.8 d^-1 (x ± S.E., N = 6).
Costs for temperature acclimatization amounted to 29 %, 24 % and 9 % of the energy required for standard, routine and spontaneous action metabolism, respectively.

Zusammenfassung

Temperaturinduzierte Stoffwechselerhöhungen bei Karpfen , Cyprinus carpio L., während Warm- und Kaltakklimatisierung
Wir haben untersucht, wie der Stoffwechsel von Cyprinus carpio im Standard-, Routine- und Spontanniveau während einer Kalt- und Warmakklimatisierung im Bereich von 7–33 °C reagiert. Dieses Verhalten wurde mit Hilfe eines Durchfluß-Respirometers ermittelt. Die "Standard Metabolic Rate" nahm zu und der Q₁₀ verringerte sich mit steigender Temeratur.
Eine quadratische Beziehung besteht zwischen den Stoffwechselraten und dem Temperaturniveau. Die durch Temperaturänderun induzierte Stoffwechselerhöhung über die Standardrate wurde für den Meßbereich mit 6.65 ± 1.97 kJ kg^-0.8 d^-1 (x ± S.E., N = 6) ermittelt.
Der Anteil temperaturinduzierter Aufwendungen entsprach 29%, 24% und 9% des Standard-, Routine- und Spontanverbrauches an Energie.     

The effect of pre-fasting diet and water temperature on liver glycogen and liver weight in rainbow trout, Salmo gairdneri Richardson, during fasting

The effect of feeding an isocaloric and isonitrogenous trout diet that contained different levels of digestible carbohydrate (cerelose) to rainbow trout at either 10 or 15° C on liver glycogen and liver weight was determined in two fasting studies of 12 and 41 days duration. Trout fed diets with increased levels of digestible carbohydrate (HC) had significantly higher liver-body weight ratios (LW) and liver glycogen (LG) than trout reared on low digestible carbohydrate diets (HF). Both LW and LG declined in fasting trout previously fed HC diets but declined little in fasting trout previously fed HF diets. Trout reared at 10° C had higher LW and LG than trout reared at 15° C on either the HC or HF diets. During fasting, the trout reared on HC diets at 10° C required a longer period of time for the LG and LW to decline to the levels of trout reared on the low carbohydrate diets, than did trout reared on the HC diets at 15° C. The results indicate that both pre-fasting diet and water temperature can affect liver glycogen utilization and liver weight in fasting trout. Prolonged elevation of LW and LG in fasting trout could jeopardize the survival rate of stocked trout, particularly at low water temperatures.     

Temperature-induced changes of early development and yolk utilization in the African catfish Clarias gariepinus

Artificially fertilized eggs and yolk-sac larvae of a freshwater tropical/subtropical fish Clarias gariepinus receiving no external food were incubated at 22, 25 and 28° C until full yolk resorption. Developmental time, size and matter composition (CHNS-O Analyzer and ashing) were assessed at egg fertilization, hatching and yolk resorption; respiration was measured every 4–5 h. The course of acceleration of C. gariepinus embryonic developmental rate with temperature ( Q_{10 dev}) was compared over the temperature range to those of Cyprinus carpio and Oncorhynchus mykiss ; they differed greatly, but were similar when compared on the basis of effective temperatures specific to each fish. Specific growth rates for energy (88, 150 and 183% per day at 22,25 and 28° C, respectively) as well as the conversion efficiencies of egg energy (64, 71 and 68%, respectively) and protein (71, 78 and 76%, respectively) in C. gariepinus larval tissues were higher than those known for the endogenous feeding period of coldwater and temperate fish species. In C. gariepinus at the end of yolk resorption, the carbon percentage and caloric values of dry weight, size (in terms of dry matter, minerals, protein and energy per larva) and transformation efficiencies were lowest at 22° C, highest at 25° C and had slightly decreased at 28° C. A tentative mechanism which leads to the positive or negative response of body size to temperature over the viable temperature range is defined.     

The effect of temperature and mass on routine metabolism in Sarotherodon (Tilapia)mossambicus (Peters)

A reappraisal of oxygen uptake by Sarotherodon mossambicus was undertaken using a continuous flow respirometer. Measurements were obtained over the temperature range 16°C–37°C for fish weighing between 10 g and 150 g. Oxygen uptake was converted to energy equivalents ( Q _ox) using the value 13.68 J mg O₂^–1and the routine metabolic energy expenditure can be described by the equation E =0.0086 t ^{2 0783} M ^{0 652} where E is the energy requirement for routine metabolism expressed in J h^-1, t the temperature in °C and M the mass in g.     

A thrombelastographic study of the effect of stress on the blood coagulation in Cyprinus carpio (Cyprinidae) and Oreochromis mossambicus (Cichlidae)

The normal blood coagulation in Cyprinus carpio and Oreochromis mossambicus was investigated by thrombelastography and standard thrombelastographs were obtained for each species. The effect of stress on blood coagulation was thereafter determined. The thrombelastograms indicated hypercoagulability under stress conditions. A prominent observation is the differences in the elasticity of the clot under various conditions. Fibrinolysis occurred in all cases, except in the case of Cyprinus carpio after severe agitation for 30 min. Relevant values for various parameters are given.     

The uptake of the anaesthetic benzocaine hydrochloride by the gills and the skin of three freshwater fish species

The uptake of benzocaine hydrochloride and neutralized benzocaine hydrochloride by the skin and the gills of Cyprinus carpio, Oreochromis mossambicus and Salmo gairdneri were studied. The differences observed can mainly be ascribed to degree of ionization and the lipid solubility of the anaesthetic.     

Effects of temperature and ration level on the growth and food conversion efficiency of Salmo gairdneri, Richardson

The effects of temperature and ration size on the growth rate and gross efficiency of food conversion of juvenile rainbow trout Salmo gairdneri were evaluated during 25-day seasonal experiments. Rations ranged from near-starvation to repletion levels. Test temperatures were 3 and 6°C higher than the controls which fluctuated dielly and seasonally. At rations near maintenance, elevated temperatures decreased trout growth. As the feeding rate increased the detrimental effect of temperature on growth was ameliorated. At repletion feeding levels, elevated temperature up to 17°C improved trout growth by increasing the maximum food consumption rate. With a temperature increase from 6.9 to 22.5°C maintenance rations increased from 2.2 to 7.5 % body weight per day. Gross efficiency was dependent upon ration level and temperature. As the food consumption rate increased, efficiency increased to a maximum, then generally declined at repletion levels. Elevated temperatures resulted in reduced efficiencies at low consumption rates but temperatures had little effect at high ration levels. A field study provided estimates of the food consumption relationships established in the laboratory, suggested any substantial increase of stream temperature without a concomitant increase of food abundance would result in decreased trout production.     

Daylight responses to overhead cover in stream channels for fry of four salmonid species

Brown trout ( Salmo trutta ), Atlantic salmon ( Salmo salar ), brook trout ( Salvelinus fontinalis ) and lake trout ( Salvelinus namaycush ) fry entering the free-feeding stage, were tested for overhead cover preferences in stream channels at different temperatures and water velocities. Atlantic salmon showed strong preferences for overhead cover, brown trout moderate preferences, whereas lake trout had preferences only at high temperatures, i.e. 12.4–19.2°C. Brook trout showed no cover preferences. Temperature influenced cover preferences of Atlantic salmon and brown trout considerably. The fry tended to seek more cover at low temperatures, i.e. 6.0–8.3°C     

Some chemical and physical characteristics of the semen of Cyprinus carpio L. and Oreochromis mossambicus (Peters)

The chemical and physical characteristics of the semen of Cyprinus carpio and Oreochromis mossambicus were investigated on a comparative and seasonal basis. Results were obtained for the volume, colour and viscosity of the semen, the percentage live spermatozoa, sperm concentrations and the degree and the duration of sperm motility under different environmental conditions. All showed distinct interspecific and less conspicuous seasonal intraspecific differences. Values have also been determined for the organic and inorganic components and the pH and osmolality of the seminal fluid. Some inorganic and organic components indicated seasonal intraspecific differences while all the components, with the exception of sodium and galactose, indicated significant interspecific differences. These observations suggest significant interspecific differences in the testicular secretions of the two fish species which add to the basic physiological differences recorded for the spermatozoa of C. carpio and O. mossambicus . The probable function of the carbohydrates, protein and enzymes present in the semen of these fish species are discussed.