Metazoan fauna parasitizing Peckoltia braueri and Pterygoplichthys pardalis (Loricariidae) catfishes from the northeastern Brazilian Amazon

Abstract

This study investigated the metazoan parasite fauna in Peckoltia braueri and Pterygoplichthys pardalis from a tributary of the Amazon River system, in northern Brazil. In P. braueri, 630 parasites were collected, belonging to Unilatus unilatus, Nothogyrodactylus sp., Genarchella genarchella, Proteocephalus sp., Gorytocephalus elongorchis, Dolops longicauda and Hirudinea gen. sp., with a dominance of monogenean species. In P. pardalis, 120 parasites were collected, belonging to U. unilatus, Acanthostomum gnerii and Gorytocephalus elongorchis, and this acanthocephalan was the dominant species. In both hosts, the parasites presented clumped distribution, high prevalence, low abundance, low Shannon diversity, and low species richness, with a predominance of helminth species. In P. braueri, host length was positively correlated with parasite species richness and Shannon index. There was no difference in the body condition of parasitized and non-parasitized fishes in either host. This was the first report of these parasites in P. braueri and P. pardalis. KEYWORDS: Digenea, diversity, helminths, parasites, freshwater fishes. Fauna de metazoários parasitando Peckoltia braueri e Pterygoplichthys pardalis (Loricariidae), bagres do nordeste da Amazônia brasileira RESUMOEste estudo investigou a fauna de parasitos metazoários em Peckoltia braueri e Pterygoplichthys pardalis de um tributário do sistema do Rio Amazonas, no Amapá, norte do Brasil. Em P. braueri foram coletados 630 parasitos das espécies Unilatus unilatus, Nothogyrodactylus sp., Genarchella genarchella, Proteocephalus sp., Gorytocephalus elongorchis, Dolops longicauda e Hirudinea gen. sp., com dominância das espécies de monogenoideas. Em P. pardalis foram coletados 120 parasitos das espécies U. unilatus, Acanthostomum gnerii e Gorytocephalus elongorchis, sendo este acantocéfalo a espécie dominante. Os parasitos em ambos hospedeiros apresentaram dispersão agregada, elevada prevalência, baixa abundância, baixa diversidade de Shannon e baixa riqueza de espécies, com predominância de espécies de helmintos. Em P. braueri, o comprimento dos hospedeiros apresentou correlação positiva com a riqueza de espécies de parasitos e o índice de Shannon. Não houve diferença entre a condição corporal de peixes parasitados e não parasitados para os dois hospedeiros. Este foi o primeiro relato desses parasitos para P. braueri e P. pardalis.

<b>Parasites in Loricariidae from Brazil: checklist and new records for fish from the Brazilian Amazon

“…Some patterns of composition and structure of the parasite community in Loricariidae from Brazil were detected: (a) presence of ectoparasites (Protozoa, Monogenea, Crustacea and Hirudinea) and endoparasites (Nematoda, Digenea, Acantocephala and Cestoda); (b) dominance of Austrodiplostomum compactum Lutz, 1928; infracommunities of ectoparasites richer and more diverse than endoparasites; (d) the presence of endoparasites at the larval stage with high prevalence and low abundance; (e) overdispersion of parasites and (f) interspecific associations of parasite infracommunities (Table 1). There are few studies on parasites in Loricariidae species in the Igarapé Fortaleza basin (Gonçalveset al, 2014;Cardoso et al, 2017). However, this was the first study for A. leucostictus, H. ventromaculatus, Ancistrus sp.…”

“…In wild fish populations, the parasitic fauna depend on internal and external factors such as: seasonal variations, habitat, limnological characteristics, water body depth, local biota, biological and physiological characteristics of the hosts, trophic level of thost population and geography of region (Dogiel, 1961;Lagrue et al, 2011;Cardoso et al, 2017;Baia et al, 2018). The parasites, including monogeneans, can then be positively or negatively influenced by environmental stressors, mainly by anthropic actions that favor the eutrophication of water bodies, altering the parasites abundance in polluted environments (Takemoto et al, 2009).…”

“…Digeneans are parasites of different host species and have mollusks as primary intermediate hosts, and fish can be intermediate, paratenic or definitive hosts (Ferrari-Hoeinghaus et al, 2007;Cardoso et al, 2017). Genarchella gernachella does not have host specificity, since it infects several Characiformes and Siluriformes fish from Brazil, which can be definitive hosts for this digenean specie (Cardoso et al, 2017). Undetermined metacercariae and G. gernachella were found in A. leucostictus, Ancistrus sp.…”

“…Parasites play an important role in ecosystems, since they can regulate the abundance of host fish populations, destabilize food chains and alter the structure of communities of hosts (Luque & Poulin, 2007;Lagrue, Kelly, Hicks, & Poulin, 2011;Cardoso, Oliveira, Neves & Tavares-Dias, 2017;Baia, Florentino, Silva & Tavares-Dias, 2018). As parasites are components of most ecosystems, occurring in all food webs and at all trophic levels, several vertebrate and invertebrate species serve as hosts for one or more species of parasites (Lagrue et al, 2011;Cardoso et al, 2017;Baia et al, 2018). In wild fish populations, parasite communities differ in richness and diversity according to their behavior, diet of hosts and the parasite life cycle.…”

“…In wild fish populations, parasite communities differ in richness and diversity according to their behavior, diet of hosts and the parasite life cycle. The different species of fish living in sympatry may present a similar pattern of parasites when compared to species living in allopatry (Cardoso et al, 2017). Thus, this study compared the parasite fauna in A. leucostictus, H. ventromaculatus, Ancistrus sp.…”