Comparison of the Histological Structure of Gill Tissue in Local Common Carp and Catfish and Their Relationship to Oxygen Requirements

Mohammed, Ahmed; Kareem, Muayad Naeem; Azawi, Noor Adnan; Al-Juhaishi, Oday Alawi

doi:10.21608/ejabf.2025.416430.6456

Comparison of the Histological Structure of Gill Tissue in Local Common Carp and Catfish and Their Relationship to Oxygen Requirements

Document Type : Original Article

Authors

¹ Department of Anatomy, College of Medicine, Tikrit University, Iraq.

² Department of Biology, College of Science, Kerbala University

³ Department of Anatomy and Histology, College of Veterinary Medicine, Tikrit University

⁴ Department of Anatomy and Histology, College of Veterinary Medicine. Tikrit University

10.21608/ejabf.2025.416430.6456

Abstract

Fish are considered one of the aquatic species that have a high diversity in nature, due to their ability to adapt to various environments. These adaptations assist in the reduction of the consumption of energy, depending on the required of water body. Consequently, the gills serve as the sites for adaptation between the internal and external environments because of their main role in respiration. Twenty samples were taken from two different species of Iraqi fish, including ten from common carp and another ten from catfish. Specimens were collected from gills for histological analyses, and a hematoxylin and eosin stain were used for general description of the structures. In both investigated species in the current study, their gills were found to be composed of cartilaginous arches that contained rows of plates organized by bundles of connective tissue and lined with a layer of simple squamous or cuboidal epithelium, as well as goblet cells. The main difference was that the gills of the catfish have larger surface area comparative to those of common carp. Also, it was noted that the gill structure in catfish may be modified to assist in getting a large amount of oxygen while use less energy. The finding indicated active fish’s, such as catfish, contain a wide surface area that increases the ability of an adequate amount of oxygen absorption during various environmental circumstances.

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