ABSTRACT
This study evaluated the growth performance and parasite load of angelfish juveniles Pterophyllum scalare kept at different stocking densities using two rearing systems. The experiment was conducted in a factorial design (4x2) with four stocking densities (0.1, 0.4, 0.7, and 1.0 g/L), two type of aquarium tanks (glass and ceramic aquariums), and four replicates. The experiment lasted 60 days using 148 juvenile fish (3.05 ± 0.09 g) randomly placed in 32 aquariums (50 L) equipped with filters and aeration. All fish received two meals a day ad libitum (8:00 and 16:00). Water quality parameters such as temperature, dissolved oxygen, pH, and total ammonia were measured. At the end of the experiment, all fish were measured and weighed to determine growth performance and then subjected to parasitological analysis. The data were analyzed with a two-way ANOVA with post-hoc Tukey test (p<0.05). No effects on growth performance at different stocking densities were observed. However, there was an increase in Capillaria pterophylli infestation in the high stocking density within ceramic aquariums. Thus, this study recommends the use of 1.0 g/L for the intensive aquaculture system of freshwater angelfish, and applying cleaning management to avoid parasite infestation, particularly in ceramic aquariums.
Subject(s)
Parasite Load , Population Density , Animals , Fish Diseases/parasitology , Aquaculture/methodsABSTRACT
O objetivo deste trabalho foi avaliar as respostas hematológicas do acari-bola Peckoltia oligospila submetido ao estresse de transporte. Variações nos parâmetros de sangue foram analisadas às zero, seis, 24, 48, 72 e 96 horas após o transporte. Respostas ao estresse foram observadas entre zero e seis horas do transporte, mas a maioria dos parâmetros retornou aos valores basais em 24 horas. O tempo de zero hora (momento imediato após transporte) foi o mais crítico, com valores elevados de glicemia, eritrócitos e eritroblastos. Respostas secundárias tardias foram observadas para a proteína plasmática total, o volume corpuscular médio (VCM) e a hemoglobina corpuscular média (HCM) em seis horas após o transporte dos peixes, retornando aos valores basais após esse período. O número de leucócitos não sofreu alterações após o transporte. O estresse de transporte não comprometeu a fisiologia de P. oligospila, o que indica que esse peixe é resistente ao estresse se comparado com outras espécies. Porém, recomenda-se que não se realize qualquer outro procedimento estressante durante pelo menos 24 horas da recuperação dos peixes após transporte, para garantir a saúde e a sobrevivência dos animais transportados.(AU)
The objective of this work was to evaluate the hematological responses of bola-pleco (Peckoltia oligospila) undergoing the stress of transportation. Variations on blood parameters were analyzed at 0, 6, 24, 48, 72 and 96h after transportation. Responses to stress were detected from 0 to 6h after the transportation of fish, however, most parameters returned to baselines values within 24h of transportation. The moment of 0h was the most critical, presenting higher values of glycemia, erythroblasts and erythrocytes. Late secondary responses were observed to total plasmatic protein, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) at 6h, returning to baselines values after this time. Leukocyte number was not affected by stress of transportation. The stress by transportation was not severe to influence the health of P. oligospila, indicating that fish is resistant to stress if compared to other species. However, we recommended no stressful procedures for at least 24 hours for recovery, in order to ensure health and survival of fish.(AU)
