Browsing by Subject "Ultrastructure"
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Early effects of nutritional stress on the liver of milkfish, Chanos chanos (Forsskal), and on the hepatopancreas of the tiger prawn, Penaeus monodon (Fabricius) -
Aquaculture, 1984 - ElsevierAfter periods of food deprivation and subsequent feeding, hepatocytes of Chanos chanos fry and R-cells of Penaeus monodon juveniles were investigated by means of transmission electron microscope. They clearly reflect the quality of different diets and thus can be used as monitor cells. For purposes of comparison, the same diets were offered to land-dwelling isopods which are known to accept a variety of different diets. Thus, this technique could also be used as a method of determining the effectiveness of binders in artificial diets.
The effect of Brachionus plicatilis grown on three different species of phytoplankton on the ultrastructure of the hepatocytes of Chanos chanos (Forskål) fry. -
Aquaculture, 1984 - ElsevierThe effect of the rotifer, Brachionus plicatilis, grown on unialgal cultures of Isochrysis galbana, Tetraselmis sp. and Chlorella sp. on the hepatocytes of milkfish fry was evaluated by electron microscopy. Rotifers grown on the three different species of phytoplankton brought about different ultrastructural features in milkfish fry hepatocytes. Best results were obtained from fry reared on Isochrysis-fed rotifers. The use of marine Chlorella-fed rotifers as feed for fry resulted in the poorest hepatocyte ultrastructure, indicating that this was nutritionally the least adequate cultured food. None of the three diets, however, produced an optimal hepatocyte ultrastructure similar to that obtained by feeding the fry with a mixture of artificial feed and newly hatched Artemia nauplii.
Journal of Phycology, 2011 - Wiley-BlackwellNephroselmis clavistella D. G. Faria et S. Suda sp. nov. is collected from coastal sand samples from the eastern and western coasts of Okinawa-jima Island, Japan. The description of the cultured strains is based on light and electron microscopic observations. The cultured strains are phylogenetically analyzed based on 18S rDNA sequences. The cells are remarkably right–left flattened and appear round or ellipse when viewed from their right or left side, and are ∼5.0 μm in diameter. The posterior flagellum curved around the cell body at rest. A single, parietal, crescent chloroplast is yellowish green and contains one conspicuous eyespot in its anterior-ventral edge near the short flagellum base. A pyrenoid with one starch sheath is located dorsal of the chloroplast. The cells are divided by transverse binary cell division, as is common in other species of this genus. The cell body is covered with five types of scales, and among them four scale types are similar to Nephroselmis rotunda. The fifth scale type is a distinctive spiny and club-shaped stellate scale with 10 spines, four of the 10 spines extended ∼150 nm and each are slightly curved with a hook at the end, whereas six spines are club-shaped blunt ended. This scale morphology, an important taxonomic characteristic, has never been described before for the genus Nephroselmis. The cell’s morphology is distinctive from previously described Nephroselmis species, and its unique scale characteristics led us to name this newly proposed species “clavistella,” meaning club star.
The ultrastructure of the hepatocytes of the giant seaperch, Lates calcarifer (Bloch) (Pisces: Centropomidae), during starvation and refeeding with different diets. -
Asian Marine Biology, 1986 - The Marine Biological Association of HongkongThree groups of immature seaperch acclimated in the laboratory on a mixed commercial pellet and minced trashfish diet were starved for 30 days. Thereafter, the first group was starved for 7 more days, the second was refed with commercial pellets, and the third with trashfish. Through transmission electron microscopy, it was found that after the acclimation period the hepatocytes of Lates calcarifer were primarily lipid-storing. Upon starvation, the following modifications in the hepatocytes were evident: decrease of lipid reserves, hepatocyte shrinkage, mitochondrial swelling, dilation of the cisternae of the rough endoplasmic reticulum (RER), and the presence of lysosomes. Among the refed fish, only the hepatocytes of those which were given trashfish recovered from the injury. Recovery was indicated by the restitution of the morphology of the mitochondria, development of parallel stacks of RER, increase in lipid and glycogen, and the distinct compartition of the hepatocytes.