Morphometric parameters of erythroid hemocytes of alien mollusc Anadara kagoshimensis (Bivalvia, Arcidae) under normoxia and anoxia

In the present work we investigated the influence of three days anoxia on hematological parameters, morphological and functional characteristics of eryhroid cells of alien bivalve Anadara kagoshimensis . Oxygen concentration in seawater was decreased by bubbling with nitrogen gas for 5 h. Temperature was maintained at 20±1oC and photoperiod was 12h day: 12h night. Extrapallial fluids were sampled by a puncture of extrapalial cavity. Three-day exposure to anoxia caused pronounced cellular responses. At the organismic level changes were not observed, as hemoglobin concentration the total number of erythroid cells and mean hemoglobin concentration ( МСН ) remained at the level of normoxia. We observed an increase of cellular anomalies, i.e. shistocytes and erythroid cells with polymorphic nuclei, and cells undergoing reactive amitotic division, which resulted in formation of binuclear cells. Nuclear volume ( V ) increased for more than 40 % compared to control level. This increase depended on the duration of anoxia. Changes in cellular volume ( V ) possessed a complicated manner. At the end of experimental period (3rd day of anoxia) nucleo- cytoplasmic ratio was 36% lower comparing to normoxia. Exposure to anoxia did not cause mortality of erythroid cells. The number or red blood cell shades observed on slides remained at control level.