<b>Host-parasite interaction between crustaceans of six fish species from the Brazilian Amazon

Abstract

ABSTRACT. Host-parasite interactions between crustaceans and six fish species (Psectrogaster falcata, Ageneiosus ucayalensis, Acestrorhynchus falcirostris, Hemiodus unimaculatus, Serrasalmus gibbus and Geophagus proximus) from a reservoir in eastern Amazon, northern Brazil, were investigated. Eight hundred and seventy-eight parasites belonging to three crustacean species, Excorallana berbicensis, Argulus chicomendesi and Ergasilus turucuyus, which parasitized the hosts' mouth, gills and tegument, were collected from 295 fish and examined. High infestation levels were caused by E. berbicensis on the body surface of the hosts. Excorallana berbicensis showed aggregate dispersion, except in S. gibbus, while E. turucuyus showed random dispersion in A. falcirostris. The host's sex did not influence infestation by E. berbicensis, and high parasitism failed to affect the body conditions of the fish. In the case of some hosts, rainfall rates, temperature, dissolved oxygen levels and water pH affected the prevalence and abundance of E. berbicensis, the dominant parasite species. Results revealed that the environment and life-style of the hosts were determining factors in infestations by parasites. Current assay is the first report on E. berbicensis for the six hosts, as well as on A. chicomendesi for G. proximus and P. falcata.Keywords: body condition, ectoparasites, environment, freshwater fish, infestation.Interação hospedeiro-parasite entre crustáceos de seis espécies de peixes da Amazônia brasileira ESUMO. O presente estudo investigou a fauna de crustáceos parasitos em Psectrogaster falcata, Ageneiosus ucayalensis, Acestrorhynchus falcirostris, Hemiodus unimaculatus, Serrasalmus gibbus e Geophagus proximus de um reservatório da Amazônia oriental, norte do Brasil, bem como as interações parasito-hospedeiro-ambiente. Foram coletados 878 parasitos pertencentes a três espécies de crustáceos, Excorallana berbicensis, Argulus chicomendesi e Ergasilus turucuyus, que infestaram a boca, brânquias e tegumento dos hospedeiros. Elevados níveis de infestação foram causados por E. berbicensis na superfície corporal dos hospedeiros. E. berbicensis mostrou dispersão agregada, exceto em S. gibbus, enquanto E. turucuyus teve dispersão randômica em A. falcirostris. O sexo dos hospedeiros não influenciou os níveis de infestação por E. berbicensis e o elevado parasitismo não afetou as condições corporais dos peixes. Para alguns hospedeiros, foram observadas correlações significativas da prevalência e abundância de E. berbicensis com a precipitação pluviométrica, temperatura, níveis de oxigênio dissolvido e pH da água. Os resultados indicaram que o ambiente e hábito de vida dos hospedeiros foram fatores determinantes nas infestações parasitárias encontradas. Esse é o primeiro relato de E. berbicensis para esses seis hospedeiros, A. chicomendesi para G. proximus e P. falcata e E. turucuyus para H. unimaculatus.Palavras-chave: condição corporal, ectoparasitos, ambiente, peixes de água doce, infestação.

Diversity of ectoparasites and endoparasites infecting Brachyplatystoma vaillantii (Siluriformes: Pimelodidae), a large migratory catfish from the Amazon

“…The aggregated distribution pattern of parasites observed in B. vaillantii followed the same pattern reported for other freshwater host species (Guidelli et al 2003;Vasconcelos and Tavares-Dias 2016;Cardoso et al 2017;Oliveira et al 2017;Santos and Tavares-Dias 2017;Leite et al 2018). This pattern is related to random environmental variables, such as heterogeneity in host susceptibility to infections, direct reproduction of the parasite within the host and heterogeneity in the host ability to eliminate parasites by immunological response (Guidelli et al 2003;Santos and Tavares-Dias 2017;Oliveira et al 2017;Leite et al 2018).…”

“…This pattern is related to random environmental variables, such as heterogeneity in host susceptibility to infections, direct reproduction of the parasite within the host and heterogeneity in the host ability to eliminate parasites by immunological response (Guidelli et al 2003;Santos and Tavares-Dias 2017;Oliveira et al 2017;Leite et al 2018). The random distribution of E. xinguensis in B. vaillantii has also been reported for the congeneric Ergasilus turucuyus Malta & Varella, 1996 in Acestrorhynchus falcirostris Cuvier, 1819 and for Excorallana berbicensis Boone, 1918 in Serrasalmus gibbus Castelnau, 1855 (Vasconcelos and Tavares-Dias 2016). The random dispersion pattern may be related to a reduced opportunity to colonize this host in the environment (Guidelli et al 2003;Vasconcelos and Tavares-Dias 2016).…”

“…Studies on the diversity of fish parasites are important due to the role of parasites as indicators of environmental quality and ecosystem health, which are useful tools in the conservation and maintenance of local biodiversity (Cardoso et al 2017;Oliveira et al 2017;Leite et al 2018). Parasites can change the composition and structure of the host community due to alterations in the environment that influence the functioning and stability of the ecosystems (Vasconcelos and Tavares-Dias 2016;Santos and Tavares-Dias 2017;Cardoso et al 2017). Changes caused by parasites can lead to negative impacts on fishery production due to losses in quality and quantity of fish, reduction in body weight and injuries, which can result in the disposal of part of the catch (Cardoso et al 2017) and reduce the potential economic benefits that fisheries may generate.…”

Low levels of crustacean parasite infestation in fish species from the Matapi River in the state of Amapá, Brazil

“…Oliveira et al (2017) reported that in 13 host species of the Jari River (state of Amapá), the prevalence of parasites was 63.8%; they collected 399 parasite specimens. However, the diversity of crustacean parasites and their levels of infestation can be influenced by various factors relating to the biology of parasites and hosts, and by environmental factors, among others (CARVALHO et al, 2003;MAMANI et al, 2004;FONTANA et al, 2012;ALSARAKIBI et al, 2014;MIKHEEV et al, 2015;VASCONCELOS & TAVARES-DIAS, 2016). Fish hosts may be are used by these parasites for transportation (CARVALHO et al, 2003), which could be facilitated by migrating fish species.…”

Metazoan Parasites of &lt;i&gt;Geophagus proximus&lt;/i&gt;, a Cichlidae Fish from the Eastern Amazon (Brazil)

“…[5] Knowledge of parasitic infracommunities and their relationships with host fish is of great importance, as parasites play a key role in ecosystems, regulating the abundance and density of natural populations, therefore stabilizing food chains and host community structure [5] [9] [10] [11]. The present study therefore aimed to investigate the parasitic fauna of metazoans from G. proximus from Lake Juá in the Tapajós River basin, in the state of Pará, Brazil.…”