The effect of thermal shock on morphological characteristics of blood cells in Siberian sturgeon (Acipenser baerii) triploids

Abstract

The aim of the study was to evaluate the effect of thermal shock on morphotic blood elements in Siberian sturgeon Acipenser baerii triploids. The thermal shock (37 °C for 2 min) was applied in the 18 th min after fertilization. Blood was sampled from parallel cultured ten triploids and ten diploids on day 70 after hatching. Ploidy was assessed with the cytogenetic method and measurements of cellular nuclei. In the blood of triploids, significant dominance of immature red blood cells, erythrocytes with a displaced nucleus, microcytes and erythroplastids were observed. The blood of triploids was also characterized by a reduced number of lymphocytes. The percentage of neutrophil and eosinophil granulocytes was elevated; increased share of neutrophil granulocytes with a 4-, 5-or 6-segmented nucleus and eosinophil granulocytes with a nucleus consisting of three and more segments was observed. Disturbances in the picture of red blood cells can be considered as an expression of intensification of end-stage changes in triploids. The response to these changes in the blood of triploid Siberian sturgeon is an increase in the share of polymorphonuclear PMN, cells counted as microphages. Frequent presence of immature red blood cells in triploid Siberian sturgeon is a process that aims at counterbalancing the loss among these blood cells. It is the first report on morphological changes and proportions among blood cells in triploid Siberian sturgeon.

Haematology of gynogenetic diploids of Siberian sturgeon Acipenser baerii Brandt

“…In the present study such erythrocytes could be considered as a source of microcytes because the percentage of enucleated red cells was small. The blood of triploid Siberian sturgeon was characterized by significant dominance of immature red blood cells, erythrocytes with a displaced nucleus, microcytes, erythroplastids and a depressed share of lymphocytes (Wlasow and Fopp-Bayat 2011). In contrast, there was no difference in the number of lymphocytes in gynogenetic diploids compared to the control diploids in our study.…”

“…Erythrocytes with eccentric nuclei are at the process stage called enucleation (Ellis 1984). The percentage (14%) of red cells with a displaced nucleus found in the gynogenetic fish in our study was higher compared to 10% in triploid 83 A. baeri (Wlasow and Fopp-Bayat 2011). In the present study such erythrocytes could be considered as a source of microcytes because the percentage of enucleated red cells was small.…”

“…Significant reduction of all haemoglobin indices (Hb, MCH and MCHC) in the peripheral blood of gynogenetic diploid fish suggested oxygenation capacity of the blood depletion. No immature red blood cells were found, which were frequently observed in triploid Siberian sturgeons (Wlasow and Fopp-Bayat 2011). The mean corpuscular volume of red cells in gynogenetic diploid Siberian sturgeons was reduced in comparison to control, and the percentage of small erythrocytes (microcytes) was increased.…”

3‐D structure, volume, and DNA content of erythrocyte nuclei of polyploid fish

“…At lower ploidy levels most nuclei had almost ideal ellipsoid shape. It has been shown that triploid individuals possess more elongated nuclei compared to those seen in diploids (Small and Benfey, ; Arefjev and Nikolaev, ; Wlasow and Fopp‐Bayat, ). This phenomenon was seen when comparing triploid and diploid tench cell nuclei, but a relationship between odd‐number ploidy levels and elongation was not confirmed for ploidy levels higher than triploid.…”

“…Novel data on volume, surface, and 3D shape of erythrocyte nuclei in sturgeon and sturgeon hybrids of different ploidy levels, as well as tench and Cuban gar, were obtained. There seem to have been only several reports (Arefjev and Nikolaev 1991;Wlasow and Fopp-Bayat 2011) dealing with nucleus and cell volume in sturgeon species, including Siberian sturgeon (8n), beluga (4n), Russian sturgeon (8n), and their hybrids, but no information considering other sturgeon ploidy levels. Rise in ploidy levels was accompanied by growth of the nuclei and an increased number of more flattened ellipsoid nuclei with increased transverse diameter in higher ploidy levels.…”