A HISTOLOGICAL STUDY OF THE DEVELOPMENT OF THE MANTLE-EDGE AND SHELL IN THE FRESHWATER GASTROPOD, HELISOMA DURYI EUDISCUS (PILSBRY)

1967 ◽  
Vol 45 (6) ◽  
pp. 1169-1181 ◽  
Author(s):  
S. P. Kapur ◽  
M. A. Gibson

The mantle-edge originates as a peripheral thickening of the evaginated shell gland. During the prehatching stages, it differentiates to form a dorsal lobe including the mantle-edge gland, a median lobe, and a ventral lobe possessing numerous mucous glands. The connective tissue core contains yellow body cells, amoebocytes, and mucoprotein glands. The protoconch is composed of fibers embedded in an amorphous ground substance. Initially it is secreted by the entire mantle-edge but, as development advances, its secretion is progressively limited to the mantle-edge gland. The adult shell is composed of the periostracum, crystalline layer, and an inner layer. The periostracum is a highly tanned layer of fibers embedded in a ground substance. The crystalline layer consists of calcium crystals, the smaller of which contain a nucleus. The inner layer is composed of organic plates which possess amoebocyte nuclei, yellow bodies and calcium granules, and which are surrounded by a thick envelope containing sulfated mucopolysaccharides. These calcium crystals and organic plates are embedded in a ground substance. It is believed that the mantle-edge gland produces the periostracum, that the dorsal lobe contributes to the inner two shell layers, and that the mucous and mucoprotein glands, yellow body cells, and amoebocytes play a significant role in the deposition and calcification of the shell.

1968 ◽  
Vol 46 (3) ◽  
pp. 481-491 ◽  
Author(s):  
S. P. Kapur ◽  
M. A. Gibson

Glycogen and ribonucleic acid are present in the mantle-edge during the prehatching period and in the adult. The cubocolumnar epithelium contains the largest stores of glycogen. Ribonucleic acid is most abundant in the mantle-edge gland, and the mucous and mucoprotein cells. Mucopolysaccharides and glycoproteins occur within the mantle-edge epithelium, excepting the mantle-edge gland, and within the shell ground substance. Mucous glands and the sheath surrounding the organic plates are rich in sulfated mucopolysaccharides. Alkaline phosphatase and calcium could not be demonstrated during the prehatching stages. In the adult, alkaline phosphatase reactions are intense along the distal border of the cubocolumnar epithelium, and the basal borders of the epithelia of the mantle-edge gland, median lobe, and ventral lobe. Calcium carbonate occurs as spherules in the connective tissue, in the extrapallial fluid, and within the organic plates and crystalline layers of the shell. In the adult, lipids are most plentiful in the dorsal lobe epithelium and yellow body cells. Vitamin A occurs only within the cubocolumnar and yellow body cells. Cytochrome oxidase is present within the mantle-edge epithelium and, in terms of relative amounts, reflects the activity of the various lobes. Similarly, the size of the Golgi element can be correlated with the activity of the mantle-edge epithelia.


1968 ◽  
Vol 46 (2) ◽  
pp. 165-167 ◽  
Author(s):  
S. P. Kapur ◽  
M. A. Gibson

The mantle-edge gland produces the highly tanned, densely fibrous periostracum, and the cubocolumnar cells contribute to the deposition of the less highly tanned matrix of the inner shell layers. The mantle-edge gland gives positive reactions for dopa oxidase and peroxidase, but does not contain melanin. The cubocolumnar cells reveal a positive reaction for dopa oxidase, possess numerous melanin granules, and exhibit a negative reaction for peroxidase. It is suggested that quinones may contribute to the process of tanning and hardening of the structural proteins of the shell. The dopa oxidase reaction within the cubocolumnar cells indicates the presence of tyrosine and suggests that these cells are capable of producing quinones to color and harden the protein component of the inner shell layers. It also explains the abundance of melanin granules within these cells. Within the mantle-edge gland, it is suggested that the peroxidase inhibits the formation of melanin from dopa quinone, and peroxidase, by accentuating quinone production, may cause further hardening of the periostracum.


Author(s):  
Hamny Hamny ◽  
Muhammad Iqbal ◽  
Sri Wahyuni ◽  
Mustafa Sabri ◽  
M. Jalaluddin ◽  
...  

The aim of this research was to determine the anatomy and histology of pancreas of water monitor lizard (Varanus salvator). Two pancreas were used in this research (a male and a female). Water monitor lizard was euthanized using chloroform and subsequently necropsied to collect the pancreas. The pancreas was washed in 0.9 % NaCl solution. Anatomical observations were carried out including location, shape, and color of pancreas, also the length and weight measurements. Then, pancreas was fixed with 4% paraformaldehyde for 7 days to proceed to histological preparation and hematoxylin eosin (HE) staining. The results of the anatomical observations showed that pancreas of water monitor lizard have two lobes, dorsal lobe (splenic lobe) and ventral lobe (duodenal lobe). Dorsal lobe which was in oval form adhered with the spleen, and ventral lobe was located in the cranial of intestines with the form of long spherical. Both of pancreas lobes were white-yellow color with the length of 1.45±0.64 cm (dorsal lobe) and 7.00±0.42 cm (ventral lobe). Weight of dorsal lobe was 0.15±0.01 g and ventral lobe was 6.35±2.30 g. The histological observations found the acinar cells, ducts, and blood vessels in both of pancreas lobes. Additionally, the similar structure of Langerhans islet only found at the ventral lobe of pancreas. In conclusion, pancreas of water monitor lizard consists of two lobes which located differently. Ventral lobe is larger than the dorsal lobe. Both lobes have similar histological structure except the Langerhans islets are only appeared in the ventral lobe.


1968 ◽  
Vol 46 (5) ◽  
pp. 987-990 ◽  
Author(s):  
S. P. Kapur ◽  
M. A. Gibson

Shortly after hatching, calcium appears in the form of numerous spherules within the connective tissue of the foot of Helisoma. Concomitantly, there is a change in the histochemical demonstration of sulfated mucopolysaccharides, glycogen, and alkaline phosphatase. The sulfated mucopolysaccharide component of the mucous glands and the mucous coating of the foot increase in staining intensity. Similarly, the glycogen content of the foot epithelium and subepithelial connective tissues increases in staining intensity. Also, alkaline phosphatase first appears and exhibits an intense staining reaction within the foot epithelium. It is suggested that the coincidental appearance of these substances is related to the percutaneous absorption and storage of calcium. It is proposed that the sulfated mucopolysaccharides absorb calcium from the environment, that this calcium–mucous complex is hydrolyzed by the alkaline phosphatase, that the released calcium becomes bound to the fibers and sulfated mucopolysaccharides forming the matrix of the spherules, and that the calcium is accumulated in the form of such spherules.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1158
Author(s):  
Dobrochna Adamek-Urbańska ◽  
Ewelina Błażewicz ◽  
Magdalena Sobień ◽  
Robert Kasprzak ◽  
Maciej Kamaszewski

Accessory respiratory organs (AROs) are a group of anatomical structures found in fish, which support the gills and skin in the process of oxygen uptake. AROs are found in many fish taxa and differ significantly, but in the suborder Anabantoidei, which has a labyrinth organ (LO), and the family Clariidae, which has a dendritic organ (DO), these structures are found in the suprabranchial cavity (SBC). In this study, the SBC walls, AROs, and gills were studied in anabantoid (Betta splendens, Ctenopoma acutirostre, Helostoma temminckii) and clariid (Clarias angolensis, Clarias batrachus) fishes. The histological structure of the investigated organs was partially similar, especially in relation to their connective tissue core; however, there were noticeable differences in the epithelial layer. There were no significant species-specific differences in the structure of the AROs within the two taxa, but the SBC walls had diversified structures, depending on the observed location. The observed differences between species suggest that the remarkable physiological and morphological plasticity of the five investigated species can be associated with structural variety within their AROs. Furthermore, based on the observed histology of the SBC walls, it is reasonable to conclude that this structure participates in the process of gas exchange, not only in clariid fish but also in anabantoids.


1952 ◽  
Vol s3-93 (24) ◽  
pp. 487-502 ◽  
Author(s):  
C. H. BROWN

1. The byssus threads, periostracum, hinge, ground substance of the shell, and the supporting material of the gills of Mytilus edulis, have been examined by physical, chemical, and histochemical means. 2. The byssus threads, periostracum, and hinge have been shown to consist of a quinone-tanned protein. 3. The byssus threads are formed in the posterior groove of the foot from the secretions of two glands, the ‘white’ gland which supplies the bulk of the protein of the thread, and the ‘purple’ gland which supplies the aromatic material responsible for the tanning. The periostracum is secreted by gland cells in the epithelium of the outer lobe of the mantle edge 4. The supporting material of the gills is a fibrous protein without quinone-tanning. This protein is in some respects similar to the untanned protein of the byssus.


1978 ◽  
Vol 56 (8) ◽  
pp. 1807-1821 ◽  
Author(s):  
Gwyneth M. Jones ◽  
A. S. M. Saleuddin

The dorsal surface of the mantle edge produces the overlying periostracum and shell; the ventral epithelium is not involved in shell formation. This regionalization is reflected in the distribution of epithelial receptors. Six ultrastructurally distinct receptor types have been identified on the ventral surface, particularly at the tip of the mantle edge, and one on the dorsal surface. Dorsal receptors occur in a single row along the edge of the mantle edge gland and are also scattered over the dorsal epithelium. Each receptor has a ciliated intraepithelial segment (receptor ending), connected to the subepithelial cell body by a narrow process, and an axon. Variation occurs in the general morphology of the receptor ending, the number of cilia, and the shape of the ciliary tuft. In most types the cell body and axon contain electron-dense granules. Ventral and dorsal receptors differ in the complexity of their subepithelial connections. Ventral receptors send their axons to branches of the pallial nerves. Intrinsic neurons are present in the pallial nerves and in connective tissue and may be responsible for neuromuscular innervation in the mantle edge. Dorsal receptors synapse with intrinsic neurons in a discrete, localised subepithelial plexus. Three types of intrinsic cell have been identified in the plexus, and synapses between them are common. Intrinsic cells form neuromuscular synapses near the plexus and may also innervate epithelial cells in regions responsible for periostracum thickening and calcium deposition.


1977 ◽  
Vol 55 (9) ◽  
pp. 1515-1522 ◽  
Author(s):  
S. B. Jackson ◽  
M. A. Gibson

Chick embryos were given a teratogenic dose of Malathion at the 5-day incubation stage and its effects on the early histogenesis of the tibiotarsus were studied during the 8- to 20-day incubation period. This investigation included studies of the growth rate as indicated by mitotic index and the number of cells per unit area, of cell activity as indicated by cell size and the amount of matrix per cell, and of matrix formation as indicated by rates of deposition and erosion and by histochemical staining. The Malathion caused an increased proliferation of the chondroblasts during the initial chondrification stages only. It led to an increase in the number and size of the chondrocytes, particularly in areas of reduced matrix deposition. The Malathion primarily influenced the deposition of the ground substance, causing: (1) a reduction in the amount of ground substance deposited, (2) a reduction in the degree of sulfation and polymerization of that ground substance which was deposited, and (3) a lysosomal-mediated resorption of the formed matrix along the epiphyseal–diaphyseal border. In these ways, the Malathion causes a reduction in the growth rate of the tibiotarsus and a weakening of the cartilage model which subsequently results in a bending of the tibiotarsus.


1971 ◽  
Vol 49 (7) ◽  
pp. 1001-1004 ◽  
Author(s):  
G. F. Haley ◽  
M. A. Gibson

An investigation was made of the influence of an environmental calcium concentration gradient on the storage of calcium spherules in Helisoma duryi eudiscus. A preliminary survey of adult snails revealed that the primary sites of calcium storage are the subepithelial connective tissues of the mantle-edge, pulmonary region, and foot. Snails were hatched and raised for 6 weeks in one of seven solutions of different calcium concentrations. These calcium chloride solutions contained the following concentrations of calcium: 1, 2, 4, 8, 16, 32, and 64 mg calcium/100 ml of demineralized water. It was found that a significantly higher number of calcium spherules are stored at both extremes of this concentration range, that is, in the 1, 32, and 64 mg calcium/100 ml solutions. The effects of the intermediate concentrations on calcium storage are not significantly different with respect to each other.


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