Histopathologic aspects in Plagioscion squamosissimus (HECKEL, 1940) induced by Neoechinorhynchus veropesoi, metacestodes and anisakidae juveniles

Abstract

Plagioscion squamosissimus (Heckel 1840), a fish endemic to the Amazon Basin and commonly known as the "silver croaker", plays an important role in the ecology and economy of Pará State, Brazil. Knowledge of host-parasite relationships is important to understanding the role of parasites in the control of natural host populations. This work describes histopathological aspects caused by several common intestinal parasites found during a helminthological survey of fish in northern Brazil. We observed a high prevalence of helminth infection, especially by J3 nematode juveniles of the family Anisakidae and metacestodes of the family Protocephalidae (both with 100% prevalence). An external capsule surrounded each juvenile with numerous juveniles inside sac-like structures formed of connective tissue. Inflammation was observed to be caused by infection of metacestodes, reaching the intestinal muscularis mucosa. Neoechinorhynchus veropesoi (38% prevalence) was found in the small intestine of P. squamosissimus, invading the mucosa, submucosa, and internal muscularis of the intestine causing intense inflammation. Histopathology of host-parasite relationships in fish has been rare, and the pathology of parasites in P. squamosissimus is described herein.

Anisakid larva parasitizing Plagioscion squamosissimus in Marajó Bay and Tapajós River, state of Pará, Brazil

“…In the present study, the infection sites were the mesentery and intestine, and these sites have also cited by other authors. Melo et al (2014) found larvae in the serosa surrounding the internal organs, in which they observed weak inflammatory reaction.…”

“…temperate South America (state of Rio de Janeiro) and tropical Atlantic (state of Pará) (SPALDING et al, 2007). Melo et al (2014) reported that anisakid larvae (without generic identification) were present as parasites in 100% of the P. squamosissimus specimens collected from the estuary of the Guamá River and the neighboring Guajará Bay, adjacent to the municipality of Belém, state of Pará. The prevalence in their study was around 75% higher than what was found in the present study for Anisakis sp.…”

“…This fish is considered to be of high commercial importance in northern Brazil, i.e. in the lower Amazon region, including the city of Santarém, state of Pará, and on the coast of the state of Amapá and in indentations of the states of Maranhão and Pará (FERREIRA et al, 1998;CAMARGO & ISSAC, 2001;MELO et al, 2014).…”

“…In Brazil, there are many records of helminth parasites in this host, including anisakid species (MARTINS et al, 2000;TAVARES et al, 2007;EIRAS et al, 2010;DIAS et al, 2011;MELO et al, 2014;RODRIGUES et al, 2015).…”

First record of Neoechinorhynchus buttnerae (Eoacantocephala, Neochinorhynchidae) on Colossoma macropomum (Characidae) in a fish farm in Roraima, Brazil

“…In the north of Brazil, some cases of acanthocephalan dissemination have been reported (Noga 2010). Recently, severe infections by the acanthocephalan Neoechinorhynchus buttnerae (Golvan, 1956) have been described in Rondônia, causing economic losses in fish farms (Chagas et al 2015;Oliveira et al 2015).Fish growth can be affected by N. buttnerae infection, since this parasite uses its proboscis to attach to the intestine tissue, causing health and pathological alterations (Melo et al 2014). Due to the importance of N. buttnerae in fish farming, the present study reports its occurrence in a fish farm in Roraima, in order to observe pathological alterations and calculate the parasite indexes in heavily infected C. macropomum.…”