Padmanabha Chakrabarti

Histoarchitecture and scanning electron microscopic studies of the olfactory epithelium in the exotic fish Puntius javanicus (Bleeker)

Histoarchitecture and scanning electron microscopic studies of the olfactory epithelium in the exotic fish Puntius javanicus (Bleeker) The olfactory epithelium of Puntius javanicus (Bleeker) was examined methodically with a light microscope (LM) and a scanning electron microscope (SEM). The ovoid olfactory apparatus consists of 25 to 26 primary lamellae arranged on both sides of the narrow median raphe. The sensory epithelium occupies the upper middle and apical half of the olfactory lamellae and consists of receptor cells (both ciliated and microvillus) and mucous cells. The region from basal part of the lamellae to the junction of the median raphe is covered with non-sensory epithelium. The non-sensory epithelium is composed of non-sensory supporting cells, stratified epithelial cells with fingerprint like microridges, and mucous cells. Budowa nabłonka węchowego u egzotycznego gatunku Puntius javanicus (Bleeker) w oparciu o badania przy użyciu elektronowego mikroskopu skaningowego Nabłonek węchowy Puntius javanicus (Bleeker) był systematycznie badany przy pomocy mikroskopu świetlnego (LM) oraz elektronowego mikroskopu skaningowego (SEM). W zarysie obła rozeta aparatu węchowego składa się z 25 do 26 głównych lameli ułożonych po obu stronach wąskiego szwu środkowego. Nabłonek węchowy zawiera centralny szew zwany rdzeniem centralnym. Nabłonek receptorowy zajmuje środkową oraz górną połowę lameli węchowych. Patrząc na to z drugiej strony, region od podstawy lameli do połączenia z szwem środkowym jest ukryty pod nabłonkiem. Z badań przy pomocy SEM wynika, iż nabłonek sensoryczny posiada zarówno urzęsione jak i mikrokosmkowe komórki czuciowe, które są wymieszane i rozmieszczone wzdłuż nabłonka. Z kolei w nabłonku wyściółkowym znajdują się komórki podporowe, uwarstwione komórki nabłonkowe przypominające mikro pręgi linii papilarnych odcisku palca oraz komórki śluzowe. Histologicznie nabłonek węchowy składa się z komórek sensorycznych i komórek podporowych ułożonych naprzemiennie w rzędach, natomiast nabłonek wyściółkowy jest objęty nie urzęsionymi komórkami podporowymi, uwarstwionymi komórkami nabłonkowymi, komórkami śluzowymi oraz niewieloma rozrzuconymi komórkami sensorycznymi.

Histological and Scanning Electron Microscopic Organization and Functional Aspects of the Surface Olfactory Epithelium of the Freshwater Minor Carp, Puntius sophore (Hamilton)

The architecture and fuction of different cells lining the olfactory epithelium of Puntius sophore (Hamilton) have been systematically studied by light and scanning electron microscope. The olfactory organ is ovoid in shape and is complicated by the presence of 16–18 lamellae on both side of the median raphe. The large area of the middle part of the olfactory lamella is covered with sensory epithelium, whereas the distal part mainly occupies by non-sensory epithelium. The sensory epithelium is composed two types of receptor cells (flagellated and microvillous) and stratified epithelial cells. The non-sensory epithelium is made up of stratified epithelial cells and mucous cells. Different cells on the olfactory epithelium have been correlated with the functional significance of the fish concerned.

FINE ANATOMICAL STRUCTURES OF THE INTESTINE IN RELATION TO RESPIRATORY FUNCTION OF AN AIR-BREATHING LOACH, LEPIDOCEPHALICHTHYS GUNTEA (ACTINOPTERYGII: CYPRINIFORMES: COBITIDAE)

Background. The omnivorous freshwater loach, Lepidocephalichthys guntea (Hamilton, 1822) inhibiting unique ecological niche where oxygen content is low. Its alimentary canal is remarkably short, which is surprising con - sidering the fact that this fish is an omnivore. This peculiarity can be correlated with the specific nature of food. Therefore, the aim of the present study was to investigate the mucosal adaptation of the intestine in adult L. gun - tea with respective digestive- as well as respiratory function. Materials and methods. The surface design of the mucosa of different sections (anterior, mid, and posterior) of the intestine of L. guntea were studied using light and scanning electron microscope following commonly accept - ed procedures. Results. The mucosa of the anterior intestine was provided with various types of mucosal folds and crowded with almost closely oval or rounded columnar epithelial cells with prominent microridges. The irregular mucosal sur - face of the mid intestine was exemplified by regularly spaced columnar epithelial cells with minute and promi - nent microridges/microvilli. On the contrary, irregular mucosal folds with stumpy villi were detected in the pos - terior intestine. The mucosal surface of that region was made up of columnar epithelial cells containing incon - spicuous microridges. In that region the submucosa was provided with increasing number of blood vessels. Various cellular elements in the anterior and mid intestine were accordingly adapted to serve the important func - tions of absorption and gas exchange. However, the arrangement of low mucosal folds and dense blood capillar - ies in between the folds in the posterior intestine unequivocally suggested its respiratory role. Conclusion. The micro-architectural pattern and cellular architecture of the anterior intestine and middle intestine of L. guntea unequivocally suggests that these two regions are adapted to serve major role of digestion and absorp - tion process. However, major changes that appear in the posterior intestine are considerably reduction of the absorptive area and the penetration of blood capillaries in between the columnar epithelial cells. Therefore, the posterior intestine of L. guntea is probably adapted to suit its role for aerial respiration. However, further investi - gation is needed the detailed physiological processes involved for aerial respiration in the region concerned.

Cyclical changes in interrenal and chromaffin cells in relation to testicular activity of olive barb, Puntius sarana (Hamilton)

Abstract The present study focused on observations of the histological status of adrenocortical tissues and the correlated seasonal changes in testicular activities in Puntius sarana (Hamilton). Interrenal and chromaffin cells were located in the head kidney between the posterior cardinal vein and hemopoietic tissues. Various male germ cells were identified in the testis based on distinctive features, distribution, and staining properties. The cytoplasmic features and the architecture of the interrenal and chromaffin cells varied during different phases of the annual reproductive cycle. The cytoplasm mass was elevated throughout maturation and spawning phases; however, it was weak in the post-spawning and growth phases. The staining intensity changed in the cells showing various phases of secretory efficiency harmonized with the constitution of different testicular cells.

Surface architecture and histoarchitecture of the olfactory rosette of freshwater lesser spiny eel, Macrognathus aculeatus (Bloch)

Surface architecture and histoarchitecture of the olfactory rosette of freshwater lesser spiny eel, Macrognathus aculeatus (Bloch) The histology and micro-architecture of different cells lining the olfactory epithelium in lesser spiny eel, Macrognathus aculeatus (Bloch), were analyzed with light and scanning electron microscopes. The leaf-like elongated olfactory rosette of the fish consists of 16 to 18 flat lamellae arranged on both sides of a narrow median raphe. Each lamella comprises a very restricted area of sensory epithelium on the extreme left corner, with the rest non-sensory epithelium. The sensory epithelium has two types of receptor cells-ciliated and microvillous, while the non-sensory epithelium comprises stratified epithelial cells, labyrinth cells, and mucous cells. The orientation of different cells on the olfactory epithelium has been correlated with the functional significance of the fish concerned. Budowa anatomiczna i histologiczna rozety węchowej u długonosa ciernistego Macrognathus aculeatus (Bloch) Narządy węchu są jednymi z kluczowych organów wykorzystywanych przez ryby do lokalizacji pokarmu, czy unikania drapieżników. Receptorami odbierającymi bodźce chemiczne są komórki węchowe. W pracy przedstawiono budowę anatomiczną oraz strukturę rozety węchowej długonosa ciernistego Macrognathus aculeatus (Bloch). Badania przeprowadzono za pomocą mikroskopu świetlnego oraz elektronowego mikroskopu skaningowego. Rozeta aparatu węchowego jest w zarysie obła i składa się z 16 do 18 blaszek głównych ułożonych po obu stronach wąskiego szwu środkowego. Komórki receptorowe zajmują jedynie ograniczoną część powierzchni blaszki. W skład nabłonka receptorowego wchodzą urzęsione komórki receptorowe i nieurzęsione komórki z mikrokosmkami. Część pozbawioną receptorów pokrywa wielorzędowy nabłonek, labirynt błon i komórki gruczołów śluzowych.

Histological, surface ultrastructural, and histochemical study of the stomach of red piranha, Pygocentrus nattereri (Kner)

Abstract The structural characterization and function of the stomach in the omnivore Pygocentrus nattereri were described using light and scanning electron microscopy. The sac-like stomach was morphologically divided into the cardiac and pyloric regions. The histological structure of the stomach consisted of four layers of the mucosa, submucosa, muscularis, and serosa. The superficial epithelium of the cardiac stomach was lined with columnar epithelial cells and the glandular epithelium contained numerous gastric glands. Gastric glands were completely absent in the pyloric portion. The mucosal surface of the stomach was a meshwork of various folds, provided with oval or rounded columnar epithelial cells which were densely packed with short, stubby microvilli. The occasional presence of conspicuous gastric pits was surrounded by epithelial cells. The localization and chemical nature of acid and neutral mucins in the various cells of the stomach was studied by employing combined the Alcian Blue-Periodic Acid Schiff (AB-PAS) technique. The deposition of glycogen was detected in the gastric glands as well as in the epithelial lining of the stomach. The utmost reactions for protein and tryptophan were recorded in the gastric glands of mucosa. The cellular organization and histochemical characterization of the stomach are discussed in relation to the feeding and digestion of the fish concerned.

Histophysiological and surface ultrastructural studies of the saccus vasculosus of Notopterus chitala (Hamilton)

We investigated the cytoarchitecture and surface ultrastructural characteristics of different cells lining the epithelium of the saccus vasculosus of Notopterus chitala (Hamilton, 1822). The saccus vasculosus, the richly vascularized reddish, sac like organ is situated on the ventral aspect of the diencephalon just behind the pituitary gland. Histologically, the saccus vasculosus consisted of several loculi lined with a heterogeneous population of a large number of specialized coronet cells and a smaller number of alternately arranged supporting cells. The loculi were densely surrounded by blood sinusoids. The loculi opened into several collecting channels that united and ultimately drained into the third ventricle of the brain. The coronet cells possessed central or basal nuclei and an apical globular protrusion. Under scanning electron microscopy, the coronet cells were variable in shape with prominent nuclei. The supporting cells were triangular in shape and placed in between the coronet cells. The apical parts of the coronet cells had different shapes of globular protrusions with distinct stalks. Intense silver stain was noted in the terminal end of the coronet cells and nerves were attached with blood vessels. Under scanning electron microscopy observation, nerve fibers of different caliber were attached to the coronet cells and blood vessels. The various cells of the saccus vasculosus in N. chitala were correlated with their functional significance.

Season-Induced Changes in the Liver Cells and Ovarian Tissues During Growth, Maturation, Spawning and Post-spawning Phases in Spiny Eel Mastacembelus armatus (Lacepède, 1800)

Cytological status of hepatocytes in respect to seasons influencing ovarian activities has been studied in Mastacembelusarmatus (Hamilton). Histologically, the hepatocyte of female liver was provided with distinct nucleus and basophilic cytoplasmic granules. In M. armatus different germ line cells were recognized on the basis of size and histoarchitecture of the cells. By examining seasonal changes in relation to hepatocytes and ovary, it was found that during growth and maturation phases the density of cytoplasmic granules of hepatocytes was increased in number as well as the nucleus become hypertrophied. These features were well correlated with the occurrence of cortical alveolus and yolk granule stage in the ovary. During spawning phase the cytoplasmic granules were sparse in the hypertrophied hepatic cells. This was due to the dynamic cytological activities like vitellogenesis and occurrence of mature oocytes in the ovary. However, no significant alterations were noticed in the hepatocytes during post spawning phase due to the appearance of new germ line cells in the ovary. Cytological changes in the hepatocytes were correlated with the reproductive phases in female M. armatus.

Histomorphological and microanatomical characteristics of the olfactory organ of freshwater carp, Cirrhinus reba (Hamilton)

Abstract The morphoanatomy, cellular organization, and surface architecture of the olfactory apparatus in Cirrhinus reba (Hamilton) is described using light and scanning electron microscopy. The oval shaped olfactory rosette contained 32 ± 2 primary lamellae on each side of the median raphe, and was lodged on the floor of the olfactory chamber. The olfactory lamellae were basically flat and compactly arranged in the rosette. The olfactory chamber communicated to the outside aquatic environment through inlet and outlet apertures with a conspicuous nasal flap in between. The mid dorsal portion of the olfactory lamellae was characterized by a linguiform process. Sensory and non-sensory regions were distributed separately on each lamella. The sensory epithelium occupied the apical part including the linguiform process, whereas the resting part of the lamella was covered with non-sensory epithelium. The sensory epithelium comprised both ciliated and microvillous receptor cells distinguished by the architecture on their apical part. The non-sensory epithelium possessed mucous cells, labyrinth cells, and stratified epithelial cells with distinctive microridges. The functional importance of the different cells lining the olfactory mucosa was correlated with the ecological habits of the fish examined.

Annual Cyclical Changes in the Histological Features and Surface Ultrastructure in Ovaries of the Freshwater Featherback Notopterus notopterus (Pallas, 1769)

The feather back, Notopterus notopterus is an important food fish. Its ovary is an extremely dynamic organ and the oocytes present an asynchronous development. Variations in ovary weight, GSI, diameter of oocytes were studied in different months of the year in this fish. Different developmental stages of female germ cells were identified on the basis of histological and ultrastructural characteristics in the ovary of N. notopterus (Pallas). In the present investigation the oocyte development of N. notopterus was divided into five stages (oogonia, perinucleolar oocyte, cortical alveolus, yolk granules stage and mature oocyte). The cytophysiological features like vitellogenesis, chorion formation and atresia of some follicles were also studied in the present investigation. The seasonal changes in the ovary have been described according to the variations in gonadosomatic index and the cytological changes of the female germ line cells.