Comparative Structural Organization of Skin in Red-Tail Shark(Epalzeorhynchos Bicolor) and Guppy (Poecilia Reticulata)

Abstract

The surface architecture and histological organization of the skin of two ornamental fish; red-tail shark (Epalzeorhynchos bicolor) and guppy (Poecilia reticulata) were the main focus of this study. The skin of the two species was composed of epidermis, dermis and hypodermis, although the epidermis showed great variations in their components in the two species. The epidermis of red-tail shark was consisted of epidermal cells, mucous goblet cells, serous goblet cells, club cells, rodlet cells and melanocytes. While, the epidermis of guppy was composed of epidermal cells, mucous goblet cells, eosinophilic granular cells, lymphocytes and melanocytes. The skin of red-tail shark included a variety of sense organs as tuberous receptor organs in the head, superficial neuromasts on the lower lips and the head, canal neuromast in the operculum and the head, and taste buds on the lips, operculum, dorsum of the head and lateral regions of the trunk. However, the skin of guppy was characterized by presence of ampullary organ on the dorsal side of the head, superficial neuromasts on the lips and the head, canal neuromast in the operculum and the head, and taste buds on the operculum, dorsum of the head and trunk regions. These structural peculiarities with histochemical features indicate additional physiological role of the skin of the two species, as the mucous goblet cells in the two species contained a considerable amount of glycoconjugates, whereas the other unicellular gland types, the serous goblet cells and club cells in red tail shark were proteinous in nature. The dermis and hypodermis was consisted of connective tissue, mainly collagenous fibers. Scanning electron microscopy indicated presence of fingerprint like-patterns of microridges of the epidermal cells, pores for lateral canal system, openings of mucous cells and taste buds with specific sensory organs in each fish species.

Conspecific injury raises an alarm in medaka

“…However, as seen in medaka here, club cells are either rare or absent in some of the species examined54849. In aaddition, anti-predator responses have been described in fathead minnows ( Pimephales promelas ) to alarm substance prepared from conspecific larvae that lacked visible club cells50.…”

Origin of Rodlet Cells and Mapping Their Distribution in Ruby-Red-Fin Shark (Rainbow Shark) Epalzeorhynchos frenatum (Teleostei: Cyprinidae): Light, Immunohistochemistry and Ultrastructure Study

“…Rodlet cells are described in different organs. They were detected in the digestive tract [3][4][5][6], pancreases [7], vascular system [8], the bulbus arteriosus [5], kidney tubules [4,6,9] the gonads [10], the skin [7], the epithelium of the operculum and gill raker [11], gill [3,4,6,9], and abdominal cavity among the mesothelial cells [6].…”

Molecular evolution of patristacin genes in teleosts based on the genome survey

“…Green lines indicate the lineage of nephrosins and pactacins, and the green dotted line indicates the loss of the nephrosin gene in Cichliformes. (Mokhtar, 2015). Therefore, the epithelium morphology is well conserved among cyprinodontiform fishes.…”

“…Histological observation indicated that mucus‐secreting cells are scattered in the epithelium of platyfish. Based on the morphology of guppy, which, like the platyfish, belongs to Cyprinodontiformes, mucous cells are located in the epidermis around the head region (Mokhtar, 2015). Therefore, the epithelium morphology is well conserved among cyprinodontiform fishes.…”