Haematological and gill responses in parasitized tilapia from valley of Tijucas River, SC, Brazil

Abstract

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.

Hematological parameters of Iranian cichlid Iranocichla hormuzensis: Coad, 1982 (Perciformes) in Mehran River

“…Low values of WBC in I. hormuzensis could be explained by its habit. This fish is found in a river environment, differently from those reported by other authors (Benli andYildis 2004, Silva et al 2009) or from fish farm (Azevedo et al 2006).…”

Seasonal influence on the hematological parameters in cultured Nile tilapia from southern Brazil

“…Low water quality in ponds located in Blumenau and Ituporanga were likely related to the lack of control in the fish stocking density and in the deposition of swine manure, respectively. The pH was kept within a typical range of values, but the highest ammonia levels observed in ponds of the Ituporanga facility did not cause fish mortality as registered by Azevedo et al (2006a). Even though the water temperature had not been keeping on the recommended range for tilapia, which is between 27 and 32 °C (Kubitza, 2000), no behaviour changes were observed.…”

Haematological changes in Nile tilapia experimentally infected with Enterococcus sp.

“…The blood was utilized to measure hematocrit (Goldenfarb et al, 1971); glucose (Accu-Chek Advantage 2 Roche) according to Azevedo et al (2006); total count of red blood cells (RBC) with haemocytometer, total count of white blood cells (WBC), and total number of thrombocytes by indirect method (Martins et al, 2004a). For differential counting of leucocytes, the smears were stained by Giemsa/May-Grunwald (Rosenfeld, 1947) in which a hundred cells were counted for the establishment of each cell contents.…”