Histopathological alterations caused by monogenean parasites the gills of tambaqui Colossoma macropomum (Serrasalmidae)

Abstract

Monogeneans are ectoparasites of fish with a global distribution. In farmed fish, high infestations may result in morbidity and mortality. This study investigated the histopathological effects of three species of monogeneans Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri on the gills of farmed Colossoma macropomum. Parasitological indices revealed a prevalence of 100%, and a mean abundance of 81.3 ± 11.8. This infection caused displacement of the gill epithelium, focal hyperplasia of epithelial cells, lamellar fusion, congestion and shortening of the secondary lamellae of gills, in addition a complete fusion of the secondary lamellae. However, these tissue alterations were reversible and punctually located lesions, which may not compromise the normal functioning of gills. Lastly, this study showed the potential damages caused by parasite monogeneans to gills of infested fish, thus sanitary management is essential for the growth of fish farm of C. macropomum.

Histopathological evaluation of Wallago attu (Bloch & Schneider, 1801) infested by ectoparasites

“…attu infested with ectoparasites (copepods, isopods and monogeneans) demonstrated serious lesions in the gill filaments such as necrosis, hemorrhages, congestion, epithelial and mucus cells proliferation. These alterations may impact the hydromineral balance, gaseous exchange, hormonal production, circulation, nitrogenous waste secretion and making the fish hypoxic or anoxic and finally lead to death and similar pathological results were also observed by Mohammadi et al, (2012) who worked on parasitic infestation of skin and gill on Oscar (Astronotus ocellatus) and discus (Symphysodon discus) and Dias et al (2021) who worked on Colossoma macropomum (Serrasalmidae), respectively. The severity of respiratory damage is directly related to the number of parasites on the gills.…”

Essential oil of Piper hispidum (Piperaceae) has efficacy against monogeneans, and effects on hematology and gill histology of Colossoma macropomum

“…In the gills of C. macropomum exposed to 100 mg/L of P. hispidum essential oil, hyperplasia with lamellar fusion was observed. In the gills of fish exposed to culture tank water + 70% alcohol (control), there was detachment of the lamellar epithelium and lamellar hyperplasia, while in fish kept with water from culture tank (control) there was detachment of the lamellar epithelium, lamellar hyperplasia and lamellar hyperplasia with fusion, probably due to also the presence of monogeneans ( Tavares-Dias et al, 2021 ). However, in C. macropomum , these lesions varied from mild to moderate, resulting in little impairment of gill functions, but that did not affected the normal functioning of the gills, according to the degree of severity of the lesions ( Schwaiger et al, 1997 ).…”

“…In Brazil, Colossoma macropomum Cuvier 1818 (Characiformes, Serrasalmidae) is considered the second largest scale fish in the Amazon basin, has presented problems of parasitic diseases caused by monogenean species in cultivation ( Alves et al, 2019 ; Barriga et al, 2020 ; Tavares-Dias et al, 2021 ; Malheiros et al, 2022 ). These helminth parasites with a direct and short life cycle and with vertical transmission, factors that facilitate high levels of infection in intensive cultivation ( Alves et al, 2019 ), cause lesions in the gills of C. macropomum that can compromise physiological processes such as breathing, excretion, acid-base balance and osmoregulation ( Tavares-Dias et al, 2021 ). Thus, this study investigated the efficacy of therapeutic baths with essential oil of P. hispidum against monogeneans of C. macropomum gills, as well as the hematological and histological effects on this fish.…”

Maceration Time Affects the Efficacy of Borage Extracts as Potential Biostimulant on Rocket Salad

“…Similarly, terpenes and phytohormones have a positive effect both by foliar spray and seed priming. Besides the biostimulant activity on plant growth and seed germination, a large group of secondary metabolites is phytotoxic and exerts an allelopathic effect [5,6]. Allelochemicals are generally divided into classes on the base of the structure and the properties, and several of them are synthetized by the shikimate pathway.…”