Kidney anatomy, histology and histometric traits associated to renosomatic index in Gymnotus inaequilabiatus (Gymnotiformes: Gymnotidae)

Abstract

The Gymnotus inaequilabiatus is a Neotropical fish widely distributed in marginal areas of bays. The aim of this study was to describe the main histological and histopathological traits in the head and exocrine kidney. Here, histometric and structural density techniques were associated with renosomatic index (RSI). The kidney was processed for light microscopy. Lipofuscin and hemosiderin content were visually estimated in the melonomacrophages centers (MMCs). All the biometric body variables were correlated with RSI, especially the kidney weight and gross lesions count. The general architecture of head and exocrine kidney was similar to that described for other teleost species. MMCs were prevalent in both portions and correlated with RSI in the head and exocrine kidney. Granulomatous structures were often observed in both portions; however, they were associated only in the exocrine kidney with RSI. Of all the structures hystometrically estimated, only proximal tubular diameter and thickness, and distal tubular thickness were correlated to renosomatic index. The RSI is an useful biometric variable that represent some physiological and morphological characteristics of kidney in G. inaequilabiatus. These findings may be used in future studies to evaluate the effects of environmental stressors on the renal adaptative physiological process.

Characterization of Lesions in Diseased Fishes, Isolation and Identification of Edwardsiella Tarda from Selected Lakes and Ponds of Ethiopia

“…The tubular epithelium lost nucleus some with pyknotic nucleus others with total loss of epithelium, the interstitial space infiltrated by inflammatory cells, degeneration of epithelium. The finding is comparable with observations of Naeemi et al[50], Mustafa et al[45] and Fernandes et al[52].The study reported by Maftuch et al[51], Koi carp due to the infection of Myxobolus sp. parasite revealed inflammatory myositis with infiltration of inflammatory cells in muscle and necrosis and hyaline degeneration in kidney was related with the current finding.Microscopic changes seen in skin, heart, and spleen that uniquely reported in this study were hyperplastic superficial mucus gland with mucus accumulation, dermal edema, focal inflammatory nodules in the dermis, dermal cell degeneration and vacuolation, melanin deposition in the dermal region, cross sectional parasitic cut in the epidermis, severe chronic myocarditis with fibrosis and the spleen showed protozoan parasites with peer shaped sporocysts, surrounding these protozoan parasites, there were typical multifocal granulomatous lesions with central necrosis followed by lymphocytic layers into which are intermingled by epitheloid macrophage.…”

Anatomy of teleost fish immune structures and organs

“…The kidney has both exocrine functions as it produces urine, and in addition endocrine functions with hormone production (Hyttel et al 2009). In fish, there is no formation of the metanephros, but after organogenesis, the pronephros and mesonephros persist together as the cephalic or head kidney and the exocrine or trunk kidney, respectively (Fernandes et al 2019). In salmon, blood supply to the excretory and other parts of the kidney is provided by aa.…”

Examination of Paraffin Sections of Different Rainbow Trout (Oncorhynchus mykiss) Tissues by Light and Scanning Electron Microscope

“…The fi sh urinary system consists of the kidney, urethra, and bladder and plays a vital role not only in the excretion of urine but also in osmoregulation [46]. In fi sh, there is no metanephros formation, the pronephros and mesonephros are present as cephalic or head kidneys and exocrine or trunk kidneys, respectively [47]. In the head kidney, there is hematopoietic tissue, and this tissue is regarded as the teleost bone marrow [48,49].…”