ABSTRACT
ABSTRACT This study describes the hematological and biometric characteristics of male and female Gymnotus species from the Pantanal, Mato Grosso do Sul state, Brazil. Fifty adult specimens of Gymnotus inaequilabiatus were weighed, measured, and then euthanized. Blood was collected by puncturing the celiac mesenteric vein to determine the hematocrit, hemoglobin content, number of erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin concentration, glucose level, absolute value of leukocytes, and relative value of leukocytes and thrombocytes. Body weight and relative condition factor did not differ (P > 0.05) between the sexes, as well as erythrogram and the blood glucose values. Hematocrit ranged from 18.0% to 54.0%; hemoglobin from 1.1 to 14.7 g dL-1; number of erythrocytes from 0.2 × 106 to 3.8 ×106 µL-1; MCV from 24.2 to 321.7 fL; and MCHC from 4.2 to 44.5 g dL-1. In the differential count were identified thrombocytes, lymphocytes, neutrophils, monocytes, basophils, immature leukocytes, and PAS-positive granular leukocyte (PAS-GL). Females had a higher percentage of immature leukocytes (P < 0.05) than males. Glucose levels, erythrogram, leukogram, and the morphology of defense cells are comparable to other fish species of the Pantanal. Thrombocytes were the most frequent defense cells, followed by lymphocytes and neutrophils.
Subject(s)
Animals , Male , Female , Gymnotiformes/anatomy & histology , Gymnotiformes/blood , Reference Values , Species Specificity , Blood Cell Count/veterinary , Blood Glucose/analysis , Brazil , Sex Factors , Biometry/methods , Wetlands , Hematologic Tests/methods , Hematologic Tests/veterinaryABSTRACT
This study describes the hematological and biometric characteristics of male and female Gymnotus species from the Pantanal, Mato Grosso do Sul state, Brazil. Fifty adult specimens of Gymnotus inaequilabiatus were weighed, measured, and then euthanized. Blood was collected by puncturing the celiac mesenteric vein to determine the hematocrit, hemoglobin content, number of erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin concentration, glucose level, absolute value of leukocytes, and relative value of leukocytes and thrombocytes. Body weight and relative condition factor did not differ (P > 0.05) between the sexes, as well as erythrogram and the blood glucose values. Hematocrit ranged from 18.0% to 54.0%; hemoglobin from 1.1 to 14.7 g dL-1; number of erythrocytes from 0.2 × 106 to 3.8 ×106 µL-1; MCV from 24.2 to 321.7 fL; and MCHC from 4.2 to 44.5 g dL-1. In the differential count were identified thrombocytes, lymphocytes, neutrophils, monocytes, basophils, immature leukocytes, and PAS-positive granular leukocyte (PAS-GL). Females had a higher percentage of immature leukocytes (P < 0.05) than males. Glucose levels, erythrogram, leukogram, and the morphology of defense cells are comparable to other fish species of the Pantanal. Thrombocytes were the most frequent defense cells, followed by lymphocytes and neutrophils.
Subject(s)
Gymnotiformes/anatomy & histology , Gymnotiformes/blood , Animals , Biometry/methods , Blood Cell Count/veterinary , Blood Glucose/analysis , Brazil , Female , Hematologic Tests/methods , Hematologic Tests/veterinary , Male , Reference Values , Sex Factors , Species Specificity , WetlandsABSTRACT
Hormones mediate sexually selected traits including advertisement signals. Hormonal co-regulation links the signal to other hormonally-mediated traits such that the tighter the integration, the more reliable the signal is as a predictor of those other traits. Androgen administration increases the duration of the communication signal pulse in both sexes of the electric fish Brachyhypopomus gauderio. To determine whether the duration of the signal pulse could function as an honest indicator of androgen levels and other androgen-mediated traits, we measured the variation in sex steroids, signal pulse duration, and sexual development throughout the breeding season of B. gauderio in marshes in Uruguay. Although the sexes had different hormone titres and signal characteristics, in both sexes circulating levels of the androgens testosterone (T) and 11-ketotestosterone (11-KT) were strongly related to signal pulse duration. Consequently, signal pulse duration can serve as an honest indicator of circulating androgens in males and females alike. Additionally, through phenotypic integration, signal pulse duration also predicts other sexual traits directly related to androgen production: gonad size in males and estradiol (E2) levels in females. Our findings show that tight hormonal phenotypic integration between advertisement signal and other sex steroid-mediated traits renders the advertisement signal an honest indicator of a suite of reproductive traits.
Subject(s)
Electricity , Gymnotiformes/physiology , Hormones/pharmacology , Animals , Behavior, Animal/drug effects , Behavior, Animal/physiology , Estradiol/blood , Female , Gymnotiformes/blood , Gymnotiformes/metabolism , Hormones/blood , Male , Models, Biological , Phenotype , Sex Characteristics , Signal Transduction/drug effects , Signal Transduction/physiology , Testosterone/analogs & derivatives , Testosterone/bloodABSTRACT
The blood infection by Trypanosoma sp. in tuvira (Gymnotus aff. inaequilabiatus) from the Pantanal wetland was reported in this study. Ten fish from the Paraguay River in the Pantanal were evaluated for the presence of hemoflagellates. Trypomastigotes of Trypanosoma sp. were observed in blood smears from three fish (30% prevalence) and some forms were seen to be undergoing division. Using the diagnostic methods of fresh examination and blood centrifugation in hematocrit capillary tubes, the prevalence rate was 80%. This is the first report of Trypanosoma sp. in tuvira in Brazil.
Subject(s)
Euglenozoa Infections/veterinary , Fish Diseases/parasitology , Gymnotiformes/parasitology , Kinetoplastida/isolation & purification , Animals , Brazil , Euglenozoa Infections/blood , Fish Diseases/blood , Gymnotiformes/blood , RiversABSTRACT
The blood infection by Trypanosoma sp. in tuvira (Gymnotus aff. inaequilabiatus) from the Pantanal wetland was reported in this study. Ten fish from the Paraguay River in the Pantanal were evaluated for the presence of hemoflagellates. Trypomastigotes of Trypanosoma sp. were observed in blood smears from three fish (30 percent prevalence) and some forms were seen to be undergoing division. Using the diagnostic methods of fresh examination and blood centrifugation in hematocrit capillary tubes, the prevalence rate was 80 percent. This is the first report of Trypanosoma sp. in tuvira in Brazil.
O objetivo do presente estudo foi reportar a infecção por Trypanosoma sp. em tuviras (Gymnotus aff. inaequilabiatus) oriundas do Pantanal Sul-mato-grossense, Brasil. Dez peixes provenientes do rio Paraguai, Pantanal Sul-mato-grossense, foram avaliados quanto à presença de hemoflagelados. Tripomastigotas de Trypanosoma sp. foram observados nas extensões sanguíneas de três peixes (30 por cento de prevalência), e algumas formas encontravam-se em divisão. Por meio do exame a fresco e da centrifugação do sangue em capilar de hematócrito como métodos para diagnóstico, a taxa de prevalência foi de 80 por cento. Esse é o primeiro relato de Trypanosoma sp. em tuviras no Brasil.
