Neoechinorhynchus buttnerae (Acanthocephala) infection in farmed Colossoma macropomum: A pathological approach

Abstract

Infection by the acanthocephalan Neoechinorhynchus buttnerae is considered the most important obstacle in farmed tambaqui or cachama (Colossoma macropomum), the second most cultivated fish species in Brazil. This study describes the occurrence of N. buttnerae in farmed this fish based on parasitological and histopathological analysis in highly infected fish. A total of 102 fish were collected from fish farms located in Brazilian states in the northern region. All of the examined fish were heavily infected by N. buttnerae and showed no signs of anorexia, but heterogeneous growth and cachexia were frequently found. No cases of mortality were observed in fish farms. Macroscopically, the intestines showed hyperaemia, hardening, thickening of the intestinal wall, yellowish mucosal secretion and a bluetongue aspect. Histological sections showed different degrees of penetration of the acanthocephalan proboscis in the intestinal tissue, surpassing the mucosa, submucosa and muscular layer, provoking dilacerations due to their spines as well as an intense inflammatory reaction composed of macrophages, Langerhans cells and lymphocytes, and granuloma formation located mainly in the submucosa layer. Submucosal oedema, an increased number of goblet cells, metaplasia areas and a reduction of the intestinal villi were also observed. The results present an important register of N. buttnerae infection in C. macropomum and contribute to the comprehension of pathogeny caused by these worms. Statement of relevance: Characid fish farming has led to significantly increased fish production in Brazil. However, the most important obstacle is the acanthocephalan infection caused by Neoechinorhynchus buttnerae in the intestinal tract. The infection does not provoke death but cachexia and growth reduction are frequently observed as well as intense pathological conditions in histological sections.

Avermectins, praziquantel and levamisole have in vitro efficacy against Neoechinorhynchus buttnerae (Neoechinorhynchidae) in Colossoma macropomum: A Serrasalmidae from the Amazon

“…Neoechinorhynchus buttnerae Golvan, 1956 is an acanthocephalan of the family Neoechinorhynchidae for which the ostracod Cypridopsis vidua (Müller, 1776) Brady, 1867 is the intermediate host (Lourenço, Morey, Pereira, & Malta, ). This endoparasite causes great problems in aquaculture production of Colossoma macropomum Cuvier, 1818 from the Brazilian Amazon, where it infects 100% of the fish (Jerônimo et al, ; Lourenço, Morey, Pereira, & Malta, ; Matos, Oliveira, Gomes, & Silva, ), affecting the intestinal tissue of hosts and causing impairments of nutrient uptake (Matos et al, ) and leading to great economic losses of 100% of production (Silva‐Gomes et al, ). However, this helminth endoparasite has been often neglected as causative agents of C. macropomum diseases.…”

The digestive tube of Piaractus brachypomus: gross morphology, histology/histochemistry of the mucosal layer and the effects of parasitism by Neoechinorhynchus sp.

“…In Brazil, acanthocephalan infections in farmed fishes have become increasingly frequent, especially in the northern region of the country (Aguiar et al, ; Chagas et al, ; Jerônimo et al, ; Lourenço et al, ; Malta et al, ; Pereira & Morey, ). Increased parasitic infections are mainly due to intensifying production in the absence of good sanitary management practices (Chagas et al, ).…”

“…In Brazil, acanthocephalan infections in farmed fishes have become increasingly frequent, especially in the northern region of the country (Aguiar et al, 2018;Chagas et al, 2015;Jerônimo et al, 2017;Lourenço et al, 2018;Malta et al, 2001;Pereira & Morey, 2018).…”

Immune response of teleost fish to helminth parasite infection

“…In specimens of S. trutta parasitized by Dentitruncus truttae, most parasites did not go beyond the granular layer, but some specimens were observed to have their proboscides in muscle layers (DEZFULI et al, 2008). Jerônimo et al (2017) observed that specimens of tambaqui (Colossoma macropomum) that were infected by the acanthocephalan Neoechinorhynchus buttnerae presented thickening and hardening of the intestinal wall. Histologically, an intense inflammatory reaction characterized by the presence of macrophages, dendritic cells and some lymphocytes was described, with formation of granulomas in the submucosal layer of some fish.…”