Cem exemplares adultos de tilápia, Oreochromis niloticus, foram inoculadas intraperitonealmente com 10(8) UFC de Mycobacterium marinum e outras 100 foram mantidas sem inoculação. Inicialmente, o sangue de 6 exemplares não inoculados foi colhido e considerado como "tempo zero". Do grupo dos inoculados foi retirado sangue de 6 animais por colheita, 1, 3, 7, 14, 21, 28, 35, 42, 49, 56 e 84 dias após inoculação. Os parâmetros hematológicos: hematócrito (Hct), taxa de hemoglobina (Hgb), contagem de eritrócitos (RBC), foram determinados e os índices hematológicos (VCM, HCM e CHCM), calculados. Foram determinados também o número de trombócitos e o número total e diferencial de leucócitos. Não ocorreram alterações nos valores de Hct, Hgb, HCM e CHCM. Entretanto houve diminuição dos valores de RBC e VCM. Os valores médios de RBC e Hct dos animais no "tempo zero" foram maiores e os de VCM e HCM, menores que os dos animais inoculados. Ocorreu neutrofilia e, após 3 dias de inoculação, ocorreram linfocitose e neutropenia nos animais. No 49º. dia após inoculação bacteriana, ocorreu monocitose.

A hundred adult of tilapia, Oreochromis niloticus, were inoculated intraperitoneally with 10(8) c.f.u. of Mycobacterium marinum. Other 100 speciemns were maintained without inoculation. Blood samples of six inoculated animals were collected at 01, 03, 07, 14, 21, 28, 35, 42, 49, 56 and 84 days after inoculation. Initially, six specimens were taken from the non inoculated group ("time zero"). The haematological parameters determined were: haematocrit (Hct), haemoglobin concentration (Hgb), total erythrocytes count (RBC), hematological indexes (MCV, MCH and MCHC), thrombocyte count (Tr), leukocyte count (WBC) and leukocyte differential count. There were no changes in Hct, Hgb, MCH and MCHC. However, the mean values for RBC and MCV decreased. The mean values for RBC and Hct of specimens from the "time zero" group were higher and the MCV and MCH lower than in inoculated animals. Occurred neutrophilia, and, at 72 h there was lymphocytosis and neutropenia. By the 49th day after bacterial inoculation, there was monocytosis.

This Study was carried out at the Salmoniculture Experimental Station "Dr. Ascanio de Faria", in Campos do Jordão, São Paulo. Brazil. The aim was to compared the hematology of triploid and diploid rainbow trout, Oncorhynchus mykiss Walbaum, 1792, by sex and gonadal maturation stages. Blood was obtained from 144 individuais for determinati-ons of: haemoglobin rate (Hb), haematocrit (Ht), erythrocyte count (Er), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MHC), mean corpuscular hemoglobin concentration (MCHC), and differential leucocyte counts. The ploid was determinated by measuring the erythrocyte major axis, in fresh and stainncd smears. Triploid rainbow trout had a large eiythrocyte diameter, mean erythrocyte volume and mean haemoglobin concentration, but lower erythrocyte count than diploid. Lymphocytes was the most frequent cell in peripherical blood.There was no dilTerence between males and females for ali parameters here analysed. The haematological analyses showcd signiffleant increase with the dcvelopment of gonadal maturation stages.

This study involved 344 Mullets, Mugil platanus Günther, 1880, captured in the estuarine region of Cananeia, São Paulo, Brazil (25º00'S, 47º55'W). The following data were recorded for each fish: total weight, total length, haemoglobin ratio (Hb), haematocrit (Ht), erythrocyte count (Er), differential leucocyte count (lymphocytes, monocytes, neutrophils, basophils and "other cells") and haematometric indices; MCV, MCH, and MCHC. The sex and stage of gonadal maturity (undifferentiated, juvenile, resting, maturing, mature, and spent) were determined by macroscopical inspection of the gonads. Parasitological inspections revealed the following infestations: Gills - Trichodinidae, Monogenea, Copepoda, and Hirudinea. Liver: cysts of Digenea. Intestine: Nematoda, Digenea and Acanthocephala. Blood: Trypanosoma sp. and Haemogregarina sp. Analysis of variance was done to evaluate how far blood and gill parasitism had any effect on total length, total weight, the biological condition factor or the measured blood parameters. Significant differences were found for the haematocrit (infested versus noninfested by Trichodinidae) and for MCHC (infested versus noninfested by Trichodinidae and Copepoda). No differences were found with regard to leucocytes.