Evaluation of the haematological parameters in Piaractus mesopotamicus Holmberg (Osteichthyes, Characidae) with Argulus sp. (Crustacea, Branchiura) infestation and treatment with organophosphate

Haematological parameters as erythrocytes, leukocytes and plasma glucose in Piaractus mesopotamicus Holmberg, 1887 were analyzed. Fish were parasitized with Argulus sp. (Crustacea, Branchiura) and treated with 0.4 mg of thriclorphon 500/L water. The effects of parasitism and the action of the treatment were evaluated. Parasitized fish showed greater number of monocytes (P>0.05) and special granulocitic cells (P<0.01) in the peripheric blood than the unparasitized (control) fish. Parasitized fish showed lower number of thrombocytes (P>0.05). Organophosphate treatment presented significantly reduction (P>0.05) in red blood cells (RBC) and hemoglobin

Haematological and gill responses in parasitized tilapia from valley of Tijucas River, SC, Brazil Respostas hematológica e branquial de tilápia parasitada do vale do Rio Tijucas, SC, Brasil

In the State of Santa Catarina there is no information about haematological and parasitological characteristics of fish maintained in feefishing operations and manured ponds. This work compared the haematological characteristics of Nile tilapia parasitized or not, captured in a property situated in Nova Trento, SC, Brazil, between August 2003 and July 2004. During the studied period, the water temperature, pH, dissolved oxygen, alkalinity, ammonia and transparency were measured. Ten fish were collected monthly either in a feefishing or in a pond receiving pig manure, and anesthetized with benzocaine solution for haematological, parasitological and histopathological exams. From a total of 360 analyzed fish, 64 (17.8%) were parasitized with Cichlidogyrus sclerosus and Cichlidogyrus sp. (Monogenoidea: Ancyrocephalidae), 20 (5.5%) with Trichodina sp. (Protozoa: Ciliophora), and four (1.1%) with Lamproglena sp. (Crustacea: Lernaeidae). The total number of erythrocytes, thrombocytes and leucocytes, glucose rate and the percentages of hematocrit, lymphocytes, monocytes and neutrophils did not show relation with parasitism. Histopathological analysis showed moderate hyperplasia and absence of congestion. The low level of parasitism found in the animals was not responsible for haematological alterations.<br>No Estado de Santa Catarina não existe informação sobre características hematológicas e parasitológicas que compare peixes mantidos em pesque-pague e com dejetos de suínos. Este trabalho estudou as características hematológicas da tilápia do Nilo parasitada ou não, capturada numa propriedade em Nova Trento, SC, Brasil, entre agosto de 2003 e julho de 2004. Durante o período a temperatura da água, pH, oxigênio, alcalinidade e transparência foram medidos. Dez peixes foram mensalmente coletados no pesque-pague e num viveiro que recebia dejetos de suínos, anestesiados com benzocaína para análise hematológica, parasitológica e histopatológica. De 360 animais analisados, 64 (17,8%) estavam parasitados com Cichlidogyrus sclerosus e Cichlidogyrus sp. (Monogenoidea: Ancyrocephalidae), 20 (5,5%) com Trichodina sp. (Protozoa: Ciliophora) e quatro (1,1%) com Lamproglena sp. (Crustacea: Lernaeidae). O número total de eritrócitos, , trombócitos e leucócitos, a taxa de glicose, os percentuais do hematócrito, linfócitos, monócitos e neutrófilos não alteraram com o parasitismo. A análise histopatológica mostrou moderada hiperplasia e ausência de congestão. O baixo nível de parasitismo não foi responsável por alterações hematológicas

Haematological characteristics of Brazilian Teleosts: III. Parameters of the hybrid tambacu (Piaractus mesopotamicus Holmberg x Colossoma macropomum Cuvier) (Osteichthyes, Characidae)

Fifty six specimens of the hybrid "tambacu" (Piaractus mesopotamicus Holmberg, 1887 male x Colossoma macropomum Cuvier, 1818 female) were collected from fishfarm of Guariba, São Paulo, to evaluate their haematology. Fishes presented 400.0 to 3,100.0 g total weight and 20.0 to 52.0 cm total length. Haemoglobin, haematocrit, mean corpuscular haemoglobin content (MCHC) and percentage of defense blood cells including leucocytes and thrombocytes, were studied. Statistical analysis showed positive correlation (P<0.01) between haematocrit, MCHC and haemoglobin rate. Nevertheless, thrombocytes and lymphocytes showed negative correlation (P<0.01)