Shields and Squyars Mortality and hematology of Ca/linectes sapidus infected with Hematodinium perezi 



145 



Days alter injection 



Figure 4 



Detectability of parasites in hemolymph of infected blue crabs over the course of infec- 

 tion. Data were combined from mortality-I and mortality-II experiments and include only 

 infected crabs. Samples sizes were 21, 11, 10, 10, 16, 4, and 4 crabs on days 7, 14, 18, 21, 

 26, 32. and 35, respectively. 



atively more parasites were observed in the heart 

 tissue over time (Table 2); but no effort was made 

 to standardize area in the histological preparations. 

 Growth of the parasite was rapid in the heart. The 

 dosage in the early infection experiment was, how- 

 ever, four times higher than that in the mortality-I 

 and mortality-II experiments; thus, results between 

 experiments were not directly comparable. 



Sporulation from the trophont stage to the dino- 

 spore stage was observed only in crabs that were 

 used to maintain infections. Parasites in one crab 



sporulated at least twice and each event lasted less 

 than 4 d. Parasite density was extraordinarily high 

 (1.6x10^ dinospores/mL) during sporulation, and 

 dropped to moderate levels (3.3 x 10^ trophonts/mL) 

 thereafter. Dinospores were observed five times over 

 the course of 26 d, beginning 43 d after injection. 

 Additionally, some crabs injected with only the tro- 

 phont (vegetative) stage were observed with Plasmo- 

 dia after 3 to 4 weeks of infection. 



Hemograms of infected crabs were significantly 

 different from those of uninfected controls (Tables 



