Fig. 4 in Kidney anatomy, histology and histometric traits associated to renosomatic index in Gymnotus inaequilabiatus (Gymnotiformes: Gymnotidae)

Fig. 4. Histological cross-sections of the head and exocrine kidney demonstrating different granulomatous structures in Gymnotus inaequilabiatus. a. severe aggregation of MMCs outer to granuloma in the exocrine kidney; PAS, bar scale = 20 µm. b. a clump of melanogenic macrophages (dark pigmented cells) adjacent to granuloma in the head kidney. The hematopoietic tissue is edematous and atypical. Some rodlet cells (black arrow) are observed. Granuloma presents a compact and thick layer of collagen with internal necrotic content surrounded by epithelioid cells (white arrows); H&E, bar scale = 10 µm. c. two well-defined granulomas with substantial internal necrotic content involved by fibrous tissue. A slight layer of MMCs aggregates close to the external wall of granuloma. TM, bar scale = 10 µm. d. MMCs aggregates both internally and externally to granuloma in the exocrine kidney. HE, bar scale = 10 µm.