Isopod parasites of Pygocentrus piraya (Characiformes: Serrasalmidae) in the lower São Francisco River, Brazil Author Brito, André Mota Alves Marcos Vinícius Teles Gomes Uedson Pereira Jacobina Marcelo Fulgêncio Guedes text Nauplius 2024 e 20240530 2024-07-08 32 1 10 https://doi.org/10.1590/2358-2936e20240530 journal article 10.1590/2358-2936e20240530 2358-2936 14667389 5ECC3D20-B88B-4D36-9123-5DA8C375B35F Braga nasuta Schioedte and Meinert, 1881 ( Fig. 3 ) Material examined . One male collected (catalogue number: CZUFS CRU-00374 ) . Supplementary description . Male: Yellowish coloration with chromatophores forming a patterned dotted dark pigmentation in distinct longitudinal bands along the body ( Fig.3A ). Laterally, body curved, with concave shape ( Fig. 3B ); compact coxal plates not extending beyond pereonites.Cephalon anteriorly truncated, with well-developed eyes.Antennule with 7 articles. Antennal bases well separated, with 8 articles ( Fig. 3C, D ). Pereopods ending in prehensile dactyls (hooks); some chromatophores also found on some pereopods; pereopod 7with shorter dactyl than others. Pleotelson triangular, ending in small point. Pleopods short ( Fig. 3E ), rounded. Pleopod 1 bilaminate, 2 quadrilaminate, 3–5 trilaminate; uropod extending beyond apex of pleotelson, with exopod slightly longer than endopod. Male appendix f lattened, tapering; small lateral and near medial peduncular lobes on all pleopods; anterior accessory gill lamellae present on pleopods 2–5. Figure 3. Braga nasuta (CZUFS CRU-00374) detected on Pygocentrus piraya ; A , B , Male, habitus in dorsal and lateral views, respectively, scale: 1 mm; C , D , antennule and antenna, respectively, arrows point to the basal article, scale: 0.5 mm; E , pleopods 1–5 (2–5 are multilaminate), scale: 0.5 mm. Host/site of infection . Pygocentrus piraya , body surface. Place of registration . Lagoa da Marituba , municipality of Penedo (state of Alagoas ) . Ecological descriptors . P = 11.1%; Im = 1.00; Am = 0.11 ± 0.33.