Effect of Thiourea on Migratory Activity of Climbing Perch Anabas testudineus and Food Consumption

Journal of Ichthyology - The effect of thiourea (exposure to 0.05% solution) on the migratory activity of the climbing perch Anabas testudineus has been studied. It is established that thiourea...     

Effect of Thiourea and Starvation on the Physiological and Biochemical State and the Reproductive System of Climbing Perch Anabas testudineus

Journal of Ichthyology - The effects of thiourea (keeping of fish for 32 days in 0.05% solution of thiourea) and of starvation (during 12 days) on the physiological and biochemical state and on the...     

Morphology of the Olfactory Organ in the Climbing Perch (Anabas testudineus,Anabantidae, Perciformes)

Biology Bulletin - The structure of the olfactory organ in the climbing perch (Anabas testudineus) has been studied by light microscopy. The anterior nostril is a short and narrow tube directed...     

Early Ontogeny of the Climbing Perch Anabas testudineus (Anabantidae) in Relation to the Buoyancy Dynamics

Journal of Ichthyology - This article describes early development of the climbing perch Anabas testudineus in relation to its buoyancy dynamics. Main patterns of the ontogeny during the first 140 h...     

Ultrastructure of the Sagitta Otolith in Different Body Size Groups of Climbing Perch Anabas testudineus (Anabantidae)

Journal of Ichthyology - The ultrastructural characteristics of the sagitta of the climbing perch, Anabas testudineus (Bloch, 1792) in different body size groups are described for the first time...     

Starvation induced cholesterogenesis in hepatic and extra hepatic tissues of climbing Perch,Anabas testudineus (Bloch)

Cholesterol is a structural lipid, which may be differentially utilized or synthesized in response to stress or during insulin deficient states such as starvation. In the present investigation we estimated the levels of cholesterol in Anabas testudineus, which was subjected to brief (15 days) and prolonged fasting (60 days). Tissues such as liver, kidney, brain, accessory respiratory organ, pectoral and lateral line muscle were selected for the study. Cholesterol content was estimated by the Crawford method (1958). Both the starvation regimes showed a significant increase in cholesterol levels in almost all the tissues, but for liver, which strangely showed an insignificant decline during the short-term starvation. This overall upsurge in cholesterol levels observed in all extra hepatic tissues may be attributed to the synthesis of stress hormones such as glucocorticoids, which may promote gluconeogenesis and adrenocorticoids, which may help the animal to combat the stressful condition of starvation. Anabas adapted well to starvation stress and survived all throughout the experimental period.     

Fine structure of the respiratory organs of the Climbing perch, Anabas testudineus (Pisces: Anabantidae)

An electron microscopic study has been made of the three respiratory organs of climbing perch. The gill structure is similar to that of the other telcosts but the thickness of the water/blood barrier is much greater, being as great as 20 μm in some specimens. The increased thickness is due to a multilayered epithelium which is thinner (3.5–7 μm) over the marginal channel of the secondary lamellae. The other two main layers, basement membrane and pillar cell flange, are relatively thin (about 1 μm).
The pillar cells have a typical structure, but in certain regions they are contiguous with one another and line well-defined blood channels. Some of the columns of basement membrane material in such regions may be common to adjacent pillar cells.
The air-breathing organs are (a) the lining of the suprabranchial chambers , and (b) the labyrinthine plates attached to the dorsal region of branchial arches. Electron microscopy showed that their structure is well adapted for gas exchange, the air/blood barriers being only 0.12–0.3 μm, comprising an epithelial layer, basement membrane, and thin capillary endothelium. The many parallel blood channels of the respiratory islets of both organs are separated by pillar-like structures which differ from the pillar cells of the secondary lamellae. Thus the hypothesis that the air-breathing organs represent modified gills is not supported by this study.
The fine structure of the non-respiratory region of the air-breathing organs is similar to that of the skin, and includes chemoreceptor-like cells. Evidence concerning the possible homology of pillar cells with plain muscle cells is discussed.     

Effect of gonadal steroids on respiratory metabolism of Anabas testudineus (Bloch)

The present investigation deals with the effect of gonadal steroids on the oxygen consumption (through gills only) in an air breathing fish, Anabas testudineus (Bloch). A good correlation (P less than 0.05) has been established between the seasonal variations in VO2 and cyclic changes in the activity of gonads in both the sexes. Oxygen consumption in both the sexes of A. testudineus were studied for a period of fourteen months. VO2 of male Anabas remained higher as compared to female throughout the period of investigation. Statistical as well as experimental analysis of the data also indicates that the "male hormones" are much more effective in bringing about the homeostasis of oxidative metabolism as compared to "female hormone" in this fish. The treatment with testosterone brings about significant (P less than 0.001) increase in VO2 in males though the lower dose proved to be most effective. Most of the "female hormones" (progesterone, Duogynon forte and Ovocyclin) used in the present investigation seem to decrease the VO2 significantly in females. The decrease in VO2 was more pronounced at higher dosage. Two peaks of VO2--first in June/July and second in October--have also been observed in this fish. The reason for and mechanism of such change are discussed in the present investigation.     

Surface area of the respiratory organs of the Climbing perch, Anabas testudineus (Pisces: Anabantidae)

Measurements have been made of the surface area of the gills and accessory respiratory organs of Anabas in the weight range 1–120 g, and the data analysed with respect to body weight using logarithmic transformations. The slope of the regression line for total gill area (0–615) is less than that found in most fish, the number of secondary lamellae/mm decreased more rapidly with body weight than for most water-breathing species (h = -0.152). The gill area of Anabas is relatively small but when the area of the accessory organs is added, the total respiratory area is of the same order as inactive water-breathing fish. The regression coefficient for combined areas of labyrinthine organs and lining of the suprabranchial chambers (0.713) exceeds that for the gills and together with other evidence (including estimates of diffusing capacity from morphological measurements), indicates an increasing importance of air-breathing of larger specimens. The average surface area of the accessory organs available for 1 ml of air within the suprabranchial chambers was found to be 2226 mm².     

Effect of hormones and pharmacological drugs on the blood of Anabas testudineus (Bloch).

Effect of different gonadal steroids, hydrocortisone, catecholamines and antithyroidal agent on certain haematological parameters in an air breathing fish, Anabas testudineus (Bloch) commonly known as climbing perch, have been made. The treatment of hydrocortisone, adrenaline, noradrenaline and testosterone brings about a significant increase in RBC counts (polycythemia), Hb content and PCV values as compared to control which were subjected to the treatment of normal saline. Males were more susceptible to the treatment of hydrocortisone, catecholamines than females. Ovocyclin, Duogynon forte and Fertyl treatments bring about anaemia in this fish, i.e. a decrease in RBC number, Hb content and PCV was clearly marked out. Females were more susceptible to Fertyl than males. Lutocyclin failed to bring any significant changes in these blood parameters. Though the treatment of thiouracil could not bring about significant changes in different blood parameters, a tendency of increase in RBC counts, Hb content and PCV was observed. The absolute values for different blood parameters have also been calculated. Possible reason and the mechanism of such changes in different blood parameters are discussed in detail.     

Curcumin and its derivatives prevent hepatocyte lipid peroxidation in Anabas testudineus

The present study evaluated the effect of five different curcuminoids, CURI, CURII, CURIII, a mixture of the three and a synthetic, curcumin–boron–oxalic acid complex, on Anabas testudineus hepatocyte lipid peroxidation after 30–60 min of incubation. The results showed that curcumin had a protective role as a strong antioxidant in teleosts. All the curcuminoids decreased the peroxidation products formed, with or without stimulating the antioxidant enzyme pathway. This suggests a direct reactive oxygen‐species scavenging ability of curcuminoids. Their antioxidant effects appear to be time and dose‐dependent.     

Synthesis and Biological Activity of Urea and Thiourea Derivatives from 2-Aminoheterocyclic Compounds

Thirty-eight N-substituted-N′-(2-thiozolyl and furfuryl)ureas and thioureas were prepared by reaction of 2-aminothiazole and 2-furfurylamine with the appropriate iso(thio)cyanate. All compounds were tested for herbicidal activity and selectivity on seedlings of wheat (a monocotyledonous plant) and cucumber (a dicotyledonous plant). Only one compound (1) out of 14 ureas was characterized by considerable herbicidal activity against the wheat seedlings and two compounds (1 and2)-towards the cucumber seedlings. The phenylurea derivative of 2-aminothiazole (1) was 1.7-fold more and the 3-chlorophenylurea derivative of 2-furfurylamine (23) was equally as active as the standard diuron with respect to selective herbicidal activity. Among 24 thioureas, four compounds (15, 16, 17, and18) to displayed the highest selective herbicidal activity and two other compounds (19 and33) were almost equal to diuron activity. Selective herbicidal ratio (SHR) represents the degree of herbicidal effect of the investigated compounds compared to diuron at both test objects. Four compounds (16,17,18, and23) possessed SHR ≪100 in the wheat seedlings while in the cucumber seedlings they had SHR ≫ 100. Therefore these compounds were substantially more active herbicides to the wheat seedlings as compared to diuron. The cytokinin-like activity of the synthesized compounds was also investigated in terms of betacyanin synthesis and radish cotyledon enlargement. The urea derivatives exhibited mostly high cytokinin-like activity but their activity remained lower than those of kinetin and N-phenyl-N′-(4-pyridyl)urea. The N-(3-fluorophenyl)-N′-(2-thiazolyl)urea (2) possessed the greatest activity at 10 μM while the corresponding compound with 3-chlorophenyl (4) was the most active cytokinin-like substance in the whole concentration range tested. Attention was also given to structure-activity relationships for the screened compounds. In general, the ureas and thioureas containing a 2-thiazole ring were more active than those containing a 2-furfuryl residue. Online publication: 7 April 2005     

Pituitary cytology of the freshwater teleost Anabas testudineus (Bloch)

In the pituitary of A. testudineus the rostral pars distalis (RPD), proximal pars distalis (PPD) and pars intermedia (PI) are arranged in a rostro-caudal axis. The rostral neurohypophysis (NH) extends dorsal to the pars distalis, while the caudal part vertically penetrates into the PI and ramifies in its component. The RPD mainly consists of erythrosinophils and PgH-positive cells which are comparable to the lactotropes and corticotropes mentioned in the literature. In the nonbreeding season, acidophils are the predominant cells of the PPD and are largely confined to its dorsal aspect. The two types of cyanophils present in the PPD could not be differentiated with the various techniques used in this study. However, those cyanophils which increase in number and are active during the spawning season may be the gonadotropes, while those which are cytologically inactive may be the thyrotropes. The pars intermedia consists of PAS+ and PhH+ cells. Trichrome and tetrachrome staining techniques revealed the presence of acidophils, cyanophils and amphiphils in the PI.     

Post-embryonic development of water- and airbreathing organs of Anabas testudineus (Bloch)

The development of respiratory surfaces in post-embryonic stages of Anabas testudineus was studied using morphometric methods on serial sections through the pharyngeal region of specimens obtained by induced breeding of known parentage. The larvae and fry were fixed in glutaraldehyde and osmium tetroxide. In the young stages aquatic respiration was found to be obligatory. The hatchlings come out of the egg membranes about 10 h after fertilization. During the yolk-sac stages gaseous exchange takes place through the well vascularized skin. The gills start differentiating at about 24 h and become functional at about 39 h. The labyrinthine organs begin to develop after 51 h but the hatchlings do not take an air breath until they reach 13–14 days. The appearance of scales at 11–14 days probably hinders cutaneous respiration and is correlated with the onset of aerial respiration.
Morphometric analysis using stereological methods shows high surface: volume ratios for the gills and labyrinthine organs as adaptations to gas exchange function. A marked decrease in surface: volume ratio for the suprabranchial cavities between 7 and 11 days indicates an increase in volume to accommodate the expanding labyrinthine plates which retain a fairly constant surface: volume ratio.     

Growth Hormone and Prolactin Action in a Teleost Anabas testudineus (Bloch): Effect of the Time of Administration

Circadian rhythms play a very important role on metabolic process and have considerable effects on growth, especially in ectotherms. Like variation in hormone levels, the sensitivity of target cells may show diurnal or seasonal fluctuations. The aim of this study was to compare the effects of morning versus evening injections of growth hormone and prolactin on malic enzyme, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and Na⁺,K⁺-ATPase in a teleost Anabas testudineus. Activities of malic enzyme, glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase of the two control groups themselves differ significantly at morning and evening. Early morning administration of growth hormone increases malic enzyme, glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase activities while evening administration of growth hormone does not effect these enzymes. Transaminase activities were stimulated by morning and evening administration of GH and PRL. Na⁺,K⁺-ATPase activity was stimulated by morning administration and inhibited by evening treatment of both hormones. The results reveal that a given hormone may provide a different message to the target tissues at different periods of the day.     

The influence of hunger on food‐stocking behaviour of climbing perch Anabas testudineus

The present study demonstrated that the climbing perch Anabas testudineus collected and stocked food pellets in its mouth, a behaviour that has not yet been reported in any other species of fish. In this species, food deprivation for 24 h increased food stocking, but not food intake.     

The suspensorium of Ctenopoma acutirostre: A comparative functional analysis with Anabas testudineus

The functional and structural aspects of the suspensorium of Ctenopoma acutirostre have been correlated with those of Anabas testudineus. The different parts of the suspensorium are described, as are the muscles that are functionally connected with the suspensorium. Functions were analyzed by observations on living specimens, and by measurements recorded from the movie films. The role played by various bones and muscles to carry out the functions (the respiration, the gulping, and the feeding) has been explained. The different bones and muscles have been considered as functional units which often are connected to form couplings. During the respiration in Ctenopoma the depression of the lower jaw is conducted by the levator operculiopercular apparatus-mandible coupling. The presence of this coupling is indicated by the presence of dorso-ventral movement of the operculum. A remarkable ventro-dorsal and antero-caudal movement in the urhyal during feeding shows in Ctenopoma the presence of the sternohyoideus-hyoid apparatus-interopercular-mandible coupling, which depresses the lower jaw. In Ctenopoma, the suspensorium takes part in respiration, gulping, and feeding, whereas in Anabas it is only involved in gulping and feeding. To carry out its functions, the suspensorium implies three articulations: palatocranial, craniohyomandibular, and quadratomandibular with the cranium and the lower jaw, respectively. Finally, the suspensorium has been analyzed as a part of the architectonic structure of the entire head by using a diagrammatic model (fig. 13) based on mutual influence, integration, and couplings.     

Oxygen uptake through water during early life of Anabas testudineus (Bloch)

The O₂ consumption (mg/hr) through water in case of Anabas testudineus during development and growth has been measured and its relationship to body weight or length studied.The logarithmic plot of 02 uptake through water either against body weight or length suggested a statistically significant (P > 3.53) two-component curve, the point of intersection being at 11 mg body weight and 1.78 cm body length. These are the theoretical values of weight or length at which the responsibility of supplementing nearly 40% of the total O₂ demand through the newly developed air breathing organ falls in the early life of the fish. One of the impelling causes forcing developing fry of Anabas to adopt a bimodal gas exchange machinery seems to be 4 fold increase in the diffusion distance at the gills.