BLOOD PROPERTIES OF ANADROMOUS ALEWR'ES 



147 



Table 1. — Comparison of six blood properties of prespawning and poslspawning alewives 



[Range In parentheses] 



Blood property 



Method of determination 



Prespawning 



Number of 

 fish tested 



Average 



Postspawnlng 



Number of 

 fish tested 



Average 



Hemoglobin 



Sedimentation rate... 

 Erythrocyte fragility - 

 Total serum proteins. 



Serum chloride 



Serum electrophoresis 



' See flg. 4. 



Cyanmethemoglobin, Lumetron colorimeter 



Westergren apparatus -- 



Saline dilutions: 0.3 to 1.5 percent 



Biuret method of Kingsley (1942), Lumetron colori 



meter. 

 Lumetron colorimeter 



Spinco model-R paper electrophoresis system 



79 

 70 

 60 

 40 

 30 

 121 



9.5 g./lOO ml. 



(4.5-12.5) 

 4.9 mm. 



(2.0-9.6) 

 0.6 percent 



(0.5-0.7) 

 5.9 g./lOO ml. 



(3.9-8.6) 

 430 mg./lOO ml. 



(355-458) 

 (I) 



9.4 g./lOO ml. 



(4.0-13.0) 

 4.7 mm. 



(1.0-12.0) 

 0.6 percent. 



(0.5-0.7) 

 6.3 g./lOO ml. 



(2.7-6.9) 

 395 mg./lOO ml. 



(302-440) 

 (0 



what higher during the pericxl of sexual activity 

 than at other times. Findings in the present study 

 indicated that average hemoglobin content of ale- 

 wives«entering fresh water to spawn is not diflFer- 

 ent from that of the spent fish returning to the 

 sea after spawning. Prespawners had an average 

 hemoglobin value of 9.5 g. per 100 ml. (range, 

 4.5-12.5), while postspawners had an average of 

 9.4 g. per 100 ml. (range 4.0-13.0). 



SEDIMENTATION RATES 



The settling rate of erythrocytes has wide clini- 

 cal use as an indicator of certain physiological 

 changes. It is higher in human females than 

 males and is greater during pregnancy and in dis- 

 ease. In fishes, Schumacher, Hamilton, and 

 Longtin (1956) found that furunculosis caused a 

 marked increase in the sedimentation rates of 

 brook trout, while Kalashnikov (1939) found that 

 the sedimentation rate increased as the gonads 

 matured. 



The present study indicated great individual 

 differences in sedimentation rates of both pre- 

 spawning and postspawning alewives (range, 1.0 

 to 12.0 mm. at 3 hours for 121 fish) . However, no 

 important changes have been disclosed by com- 

 parison of average sedimentation rates of fish 

 entering fresh water to spawn with those of spent 

 members of the same populations leaving fresh 

 water 2 months later. Average sedimentation 

 rates for prespawners were 1.2 mm. at 1 hour, 3.3 

 mm. at 2 hours and 4.9 mm. at 3 hours; for post- 

 spawners, 1.1 mm. at 1 hour, 3.2 mm. at 2 hours, 

 and 4.7 mm. at 3 hours (fig. 1). Ripe females ex- 

 hibited higher average sedimentation rates than 

 did ripe males (5.4 mm. compared with 4.3 mm. in 



3-hour readings), but this difference disappeared 

 in postspawners. 



ERYTHROCYTE FRAGILITY 



Another indication of physiological distress is 

 the lowered ability of red blood cells to withstand 

 decreasing osmotic pressure of the siuTounding 

 medium. Fragility of human erythrocytes in- 

 creases in certain diseases. Examination of ale- 

 wife blood disclosed no changes in cell fragility 

 due to the spawning migration. One-hour tests 

 showed that complete lysis occurred consistently 

 at between 0.5- and 0.7-percent saline in both pre- 

 spawning and postspawning fish. 



TOTAL SERUM PROTEINS 



The serum proteins of animals have a variety of 

 chemical and physical functions, including their 

 important role in osmotic regulation. Among the 

 invertebrates, wide individual variations (2.2 g. to 

 10.2 g. per 100 ml.) in total serum proteins 

 of the lobster (Hotnarus americanus) and even 

 greater variations (1.16 g. to 13.75 g. per 100 ml.) 

 in the crab (Cancer mag is te?') were noted by Leone 

 (1953). In fishes, average total proteins of 5.6 

 g. per 100 ml. for adult salmon (SaJmo salar), 

 and 4.9 g. per 100 ml. for Conger vvlgaris were 

 reix)rted by Drilhon, Fine, and Daoulas (1958). 

 Keys (1933) found that the total serum proteins 

 of eels dropped from 8.4 g. per 100 ml. in sea 

 water to 6.8 g. per 100 ml. in fresh water. 



The present study of prespawning and post- 

 spawning alewives has disclosed marked indi- 

 vidual variations in total serum proteins — from 

 3.9 to 8.6 g. per 100 ml. in prespawners, and from 

 2.7 to 6.9 g. per 100 ml. in postspawners (fig. 2) 



