Weight-length relationship, condition factor and blood parameters of farmed Cichla temensis Humboldt, 1821 (Cichlidae) in central Amazon

Abstract

Farming of native carnivore fish species has drawn attention due to their promising use in aquaculture. Among these species, tucunaré of the genus Cichla stand out, them being of high economical interest for sport fishing and Amazon's industry of ornamental fish. The present study describes the weight-length relationship (WLR), relative condition factor (Kn), red blood cell parameters, thrombocytes and leukocytes count of Cichla temensis Humboldt, 1821, farmed in central Amazon. Fish that underwent food training during fingerling culture received extruded ration containing 45% of crude protein during fattening, and had Kn with values from 0.925-1.199, which indicated good health condition during the culture. The equation obtained from the WLR was W = 0.0073Lt 3.1435 , indicating an isometric growth, which is the desirable for fish of fish farm. Red blood cell counts, total thrombocyte and leukocyte counts, hematocrit, hemoglobin concentration, mean corpuscular volume (MCV), concentration of mean corpuscular hemoglobin (MCHC), lymphocytes, monocytes and neutrophils had intra-specific variation. A significant (p<0.001) positive correlation of the red blood cells number with the hemoglobin concentration and hematocrit was found. These are the first sets of blood parameters for C. temensis and could be used as reference for comparison in further studies to evaluate the health status of this fish in different environments, because assessment of these parameters may be used as quick tool for diagnosing diseases, stress and malnutrition.A criação de peixes carnívoros nativos vem recebendo grande atenção devido ao promissor uso na aquicultura. Entre estes peixes destacam-se os tucunarés do gênero Cichla, de grande interesse para a pesca esportiva e a indústria de peixes ornamentais da Amazônia. O presente estudo descreve a relação peso-comprimento, fator de condição relativo (Kn) e parâmetros sanguíneos do tucunaré Cichla temensis Humboldt, 1821 cultivado na Amazônia central. Os peixes submetidos a treinamento alimentar na alevinagem receberam ração extrusada contendo 45% de proteína bruta na engorda e tiveram Kn variando de 0,925-1,199, indicando boas condições de higidez no cultivo. A equação obtida da relação peso-comprimento foi P = 0,0073.Ct 3,1435 , indicando crescimento do tipo isométrico, que é o mais desejável para peixes em uma piscicultura. O número de eritrócitos, trombócitos e leucócitos totais, hematócrito, concentração de hemoglobina, volume corpuscular médio (VCM), concentração da hemoglobina corpuscular média (CHCM), linfócitos, monócitos e neutrófilos mostrou variação intra-específica. Foi observada correlação positiva significativa (p<0,001) do número de eritrócitos totais com a concentração de hemoglobina e o hematócrito. Estes foram os primeiros resultados sobre parâmetros sanguíneos de C. temensis e poderão ser usados como referência para comparação em estudos futuros para avaliar o estado de saúde deste peixe em diferentes ambientes, pois a medida destes parâmetros pode ser usada como ferramen...

Hematological parameters of three species of the peacock bass (Cichla spp.) from Balbina lake, Presidente Figueiredo, Amazonas, Brazil

“…In the present study, the thrombocyte counts and total leukocyte counts among the peacock bass species presented significant differences. In C. temensis studied by Tavares-Dias et al (2011), the thrombocyte count was higher than that of the present study (28.619 ± 13.148 uL), thus indicating that exists accentuated increase of that cell type that can be associated to the environmental type. In that case it adapts of captivity.…”

“…In C. monoculus, it was previously observed that monocytes were the third commonest type (5.9 ± 1.1%) of leukocyte in the blood (Ranzani-Paiva et al, 2000), while in C. temensis monocytes were the second commonest type of leukocyte (9.308 ± 5.864 uL) (Tavares-Dias et al, 2011). Those values were higher than the values in the peacock bass in present study.…”

“…Regarding thrombocytes, similarity between species was also observed in peacock bass. This type was not present in the blood of C. monoculus (Ranzani-Paiva et al, 2000) or C. temensis (Tavares-Dias et al, 2011). Regarding basophils, C. temensis was found to present lower values in relation to other species.…”

“…The predominant type in C. temensis and C. vazzoleri was lymphocytes, thus indicating that in those species, leukocytes were the main defense cell in the blood. In the studies developed by Ranzani-Paiva et al (2000) and Tavares-Dias et al (2011) on C. monoculus and C. temensis respectively, lymphocytes also accounted for the largest percentage of the cell types in the blood (59.2 ± 27.5%; 9.308 ± 5.864 uL). Lymphocytes act basically in inflammatory processes.…”

“…They were higher than those of C. temensis from fish farming (Tavares-Dias et al, 2011) and were lower than those of C. monoculus originating from natural areas of the Paraná river (Ranzani-Paiva et al, 2000). These erythrogram values can be directly correlated with the fact that the peacock bass is classified as a carnivorous fish and presents high levels of natatory activity, especially when catching their prey, which requires high levels of oxygen dissolved in the water (Tavares-Dias et al, 2011).…”