lateral dorsal region of the neck (Bentley and 

 Dunbar-Cooper 1980). Some sea turtles were also 

 resampled after 3, 4, and 5 h on deck. The hemato- 

 crit was measured on board ship immediately after 

 taking the sample. Blood cells were centrifuged and 

 plasma stored on ice for transport to Miami. The 

 plasma was frozen until used (-4°C). 



The items that were measured are as follows: 

 Plasma osmotic pressure, using a Wescor vapor 

 pressure osmometer; sodium and potassium concen- 

 trations, by flame emission spectrophotometry; 

 calcium and magnesium, by atomic absorption spec- 

 trophotometry using appropriate standards (Lutz 

 1972); chloride, using an Aminco Chloridometer; and 

 urea and glucose, using enzymatic kit techniques 

 (Sigma). 



The blood chemistry values reported are means 

 + SD. Statistical differences between groups were 

 determined with Student's t test, and level of sig- 

 nificance was set at P < 0.05 for all compari- 

 sons. 



FISHERY BULLETIN: VOL. 85, NO. 1 



RESULTS 



Hematocrit 



The hematocrit levels of the loggerhead sea turtle 

 were remarkably constant and were not influenced 

 by season (Table 1). The range of values was 28-48%, 

 and the mean 35.4% is very similar to that found 

 by Dessauer (1970) for the same species (32%). The 

 sea turtles caught in December 1978 were a strik- 

 ing exception to this uniformity with very much 

 lower mean hematocrits (15%) and one individual 

 having a value as low as 5%. 



Loggerhead sea turtles resampled 3-5 h after cap- 

 ture showed some interesting changes. Four animals 

 resampled after 3 h on deck showed an average in- 

 crease in hematocrit of 10.4% (±14.89), for five 

 animals after 4 h the average increase was 4.8% 

 (±4.7), and for four animals after 5 h the hemato- 

 crit had decreased on average 15.2 (± 13.3) from the 

 initial value. The reason for this change is not clear. 



Table 1.— Blood chemistry values of loggerhead sea turtles trapped by shrimp trawl in the Port Canaveral 



of samples in parentheses. Groups that differ significantly 



38 



