Development and health status of Centropomus undecimalisparasitized by Rhabdosynochus rhabdosynochus (Monogenea) under different salinity and temperature conditions.

This study evaluated the correlation of hematological parameters with the mean abundance of the monogenean helminth Rhabdosynochus rhabdosynochus in Centropomus undecimalis reared at different temperatures and salinities. The experimental conditions were: 28 °C/0 ppt (parts per thousand); 28 °C/15 ppt; 28 °C/32 ppt; 25 °C/0 ppt; 25 °C/15 ppt; and 25 °C/32 ppt. The prevalence was 100.0% in fish at 28 °C/15 ppt, 28 °C/32 ppt and 25 °C/15 ppt, which was significantly different (p < 0.05) from those at 25 °C/32 ppt. The red blood cell (RBC) count, hematocrit and total leukocyte (WBC) count were significantly higher in fish at 28 °C/15 ppt and 28 °C/32 ppt. The mean abundance of R. rhabdosynochus, hematocrit and RBC showed positive correlations (P < 0.05) with temperature (ρ= 0.3908; ρ= 0.4771 and ρ = 0.2812). Mean abundance showed negative correlations with hemoglobin (ρ= -0.3567) and mean corpuscular hemoglobin concentration (MCHC) (ρ = -0.2684). No correlation between abundance and salinity was detected among the experimental conditions (ρ = -0.0204). The low numbers of monogeneans recorded (min -1 and max -33) explain the few changes to fish health. This suggests that these experimental conditions may be recommended for development of rearing of C. undecimalis in Brazil, without any influence or economic losses from R. rhabdosynochus.

Development and health status of Centropomus undecimalisparasitized by Rhabdosynochus rhabdosynochus (Monogenea) under different salinity and temperature conditions / Desenvolvimento e estado de saúde de Centropomus undecimalis parasitado por Rhabdosynochus rhabdosynochus (Monogenea) sob diferentes condições de salinidade e temperatura

This study evaluated the correlation of hematological parameters with the mean abundance of the monogenean helminth Rhabdosynochus rhabdosynochus in Centropomus undecimalis reared at different temperatures and salinities. The experimental conditions were: 28 °C/0 ppt (parts per thousand); 28 °C/15 ppt; 28 °C/32 ppt; 25 °C/0 ppt; 25 °C/15 ppt; and 25 °C/32 ppt. The prevalence was 100.0% in fish at 28 °C/15 ppt, 28 °C/32 ppt and 25 °C/15 ppt, which was significantly different (p 0.05) from those at 25 °C/32 ppt. The red blood cell (RBC) count, hematocrit and total leukocyte (WBC) count were significantly higher in fish at 28 °C/15 ppt and 28 °C/32 ppt. The mean abundance of R. rhabdosynochus, hematocrit and RBC showed positive correlations (P 0.05) with temperature (= 0.3908; = 0.4771 and = 0.2812). Mean abundance showed negative correlations with hemoglobin (= -0.3567) and mean corpuscular hemoglobin concentration (MCHC) ( = -0.2684). No correlation between abundance and salinity was detected among the experimental conditions ( = -0.0204). The low numbers of monogeneans recorded (min -1 and max -33) explain the few changes to fish health. This suggests that these experimental conditions may be recommended for development of rearing of C. undecimalis in Brazil, without any influence or economic losses from R. rhabdosynochus.(AU)

Este estudo avaliou a correlação dos parâmetros hematológicos com a abundância média de helmintos monogenea Rhabdosynochus rhabdosynochus em robalo-flecha, Centropomus undecimalis, cultivado em diferentes temperaturas e salinidades. As condições experimentais foram: 28 °C/0 ; 28 °C/15 ; 28 °C/32 ; 25 °C/0 ; 25 °C/15 ; 25 °C/32 . A prevalência (P) foi de 100,0% nos peixes de 28 °C/15 , 28 °C/32 , 25 °C/15 significativamente diferente (p 0,05) dos peixes de 25 °C/32 (P=75,0%). O número de eritrócitos, hematócrito e leucócitos totais foram significativamente maiores nos peixes mantidos a 28 °C/15 e 28 °C/32 . A abundância média de R. rhabdosynochus, hematócrito e número de eritrócitos mostraram correlação positiva (p 0,05) com a temperatura ( = 0,3908; = 0,4771 e = 0,2812, respectivamente). Houve correlação negativa da abundância média com a hemoglobina ( = -0,3567) e a concentração de hemoglobina corpuscular média (CHCM) ( = -0,2684). Não houve correlação entre a abundância e a salinidade entre os tratamentos ( = -0,0204). O baixo número de Monogenea registrado (mín: 1 e máx: 33) justifica as poucas alterações na saúde dos animais avaliados. Isso sugere que essas condições experimentais de cultivo podem ser recomendadas para um futuro desenvolvimento do cultivo de C. undecimalis no Brasil, sem que haja influência e perdas econômicas associadas a mortalidades, por parasitos R. rhabdosynochus.(AU)

Development and health status of Centropomus undecimalisparasitized by Rhabdosynochus rhabdosynochus (Monogenea) under different salinity and temperature conditions / Desenvolvimento e estado de saúde de Centropomus undecimalisparasitado por Rhabdosynochus rhabdosynochus (Monogenea) sob diferentes condições de salinidade e temperatura

This study evaluated the correlation of hematological parameters with the mean abundance of the monogenean helminth Rhabdosynochus rhabdosynochus in Centropomus undecimalis reared at different temperatures and salinities. The experimental conditions were: 28 °C/0 ppt (parts per thousand); 28 °C/15 ppt; 28 °C/32 ppt; 25 °C/0 ppt; 25 °C/15 ppt; and 25 °C/32 ppt. The prevalence was 100.0% in fish at 28 °C/15 ppt, 28 °C/32 ppt and 25 °C/15 ppt, which was significantly different (p < 0.05) from those at 25 °C/32 ppt. The red blood cell (RBC) count, hematocrit and total leukocyte (WBC) count were significantly higher in fish at 28 °C/15 ppt and 28 °C/32 ppt. The mean abundance of R. rhabdosynochus, hematocrit and RBC showed positive correlations (P < 0.05) with temperature (ρ= 0.3908; ρ= 0.4771 and ρ = 0.2812). Mean abundance showed negative correlations with hemoglobin (ρ= -0.3567) and mean corpuscular hemoglobin concentration (MCHC) (ρ = -0.2684). No correlation between abundance and salinity was detected among the experimental conditions (ρ = -0.0204). The low numbers of monogeneans recorded (min -1 and max -33) explain the few changes to fish health. This suggests that these experimental conditions may be recommended for development of rearing of C. undecimalis in Brazil, without any influence or economic losses from R. rhabdosynochus.

Este estudo avaliou a correlação dos parâmetros hematológicos com a abundância média de helmintos monogenea Rhabdosynochus rhabdosynochus em robalo-flecha, Centropomus undecimalis, cultivado em diferentes temperaturas e salinidades. As condições experimentais foram: 28 °C/0 ‰; 28 °C/15 ‰; 28 °C/32 ‰; 25 °C/0 ‰; 25 °C/15 ‰; 25 °C/32 ‰. A prevalência (P) foi de 100,0% nos peixes de 28 °C/15 ‰, 28 °C/32 ‰, 25 °C/15 ‰ significativamente diferente (p<0,05) dos peixes de 25 °C/32 ‰ (P=75,0%). O número de eritrócitos, hematócrito e leucócitos totais foram significativamente maiores nos peixes mantidos a 28 °C/15 ‰ e 28 °C/32 ‰. A abundância média de R. rhabdosynochus, hematócrito e número de eritrócitos mostraram correlação positiva (p<0,05) com a temperatura (ρ = 0,3908; ρ = 0,4771 e ρ = 0,2812, respectivamente). Houve correlação negativa da abundância média com a hemoglobina (ρ = -0,3567) e a concentração de hemoglobina corpuscular média (CHCM) (ρ = -0,2684). Não houve correlação entre a abundância e a salinidade entre os tratamentos (ρ = -0,0204). O baixo número de Monogenea registrado (mín: 1 e máx: 33) justifica as poucas alterações na saúde dos animais avaliados. Isso sugere que essas condições experimentais de cultivo podem ser recomendadas para um futuro desenvolvimento do cultivo de C. undecimalis no Brasil, sem que haja influência e perdas econômicas associadas a mortalidades, por parasitos R. rhabdosynochus.