Ultrastructure studies on Retina and Cornea of Octopus macropus from Egyptian Mediterranean Coasts | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 13, Volume 22, Issue 2, April 2018, Pages 163-171 PDF (801.39 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2018.21039 | ||
| Author | ||
| Tarek G. Ali | ||
| Zoology Department, Faculty of Science, Ain Shams University, Cairo, Egypt. | ||
| Abstract | ||
| Adult animals of Octopus macropus were collected alive from Abu Quir coasts, Alexandria, Egypt. They were transported to the laboratory at Faculty of Science, Ain Shams University and dissected to obtain their eyes and put in suitable fixative. After that, the routine ultrastructure techniques were applied for examination of the retina and cornea by the transmission electron microscope. The results revealed that the retina is formed of two layers; the visual cells and the connective tissue. The visual cells contain a small amount of a granular endoplasmic reticulum, rounded mitochondria and oval nuclei with distinct nucleoli. From each four different visual cells, four rhabdomeres united to form a prismatic rhabdome. Examination with higher magnification power showed presence of groups of 8 to 9 lamellated structures that form dense membranes with different lengths. These lamellated structures are similar to the myelin membranes and present in all cells but not connected to the plasma membrane. The cornea is made of three layers; the outer epithelial layer of hexagonal cells that have small mitochondria and oval nuclei. The median thick layer of fibrous connective tissue and the inner endothelium layer of cuboidal cells having small mitochondria and large rounded nuclei. | ||
| Keywords | ||
| Octopus macropus; Mediterranean coast; retina; cornea; Ultrastructure | ||
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