CHEN. M., AND G. POWER. 



1972. Infection of American smelt in Lake Ontario and 

 Lake Erie with the microsporidian parasite Glugea 

 hertwigi (Weissenberg). Can. J. Zool. 50:1183-1188. 



Haley, a. J. 



1954a. Microsporidian parasite, Glugea hertwigi, in 

 American smelt from the Great Bay region. New Hamp- 

 shire, Trans, Am, Fish, Soc, 83:84-90, 



1954b, Further observations on Glugea hertwigi Weissen- 

 berg 1911, 1913 (microsporidial in fresh water smelt in 

 New Hampshire. J. Parasitol. 40:482-483. 



Laird. M., and W. L. Bullock. 



1969. Marine fish haematozoa from New Brunswick and 

 New England. J. Fish. Res. Board Can. 26:1075-1102. 

 NEPSZY. S. J.. J. BUDD, AND A. O. DECHTIAR. 



1978. Mortality of young-of-the-year rainbow smelt (Os- 

 merus mordax) in Lake Erie associated with the occur- 

 rence ofGlugea hertwigi. J. Wildl. Dis. 14:233-239. 



PuiLiPPON, M,. B, L. Nicholson, and S. W, Sherburne. 



1977. Piscine Erythrocytic Necrosis I PEN) in the Atlantic 

 herring iClupea harengiis harengus): evidence for a viral 

 infection. Fish Health News 6:6-10. 



Reno, P., M. Philippon-Fried, B. L. Nicholson, and S. W. 

 Sherburne. 



1978. Ultrastructural studies of piscine erythrocytic ne- 

 crosis (PEN) in Atlantic herring iCIupea harengus haren- 

 gus). J. Fish. Res. Board Can. 35:148-154. 



Sherburne, S. W. 



1973. Erythrocyte degeneration in the Atlantic herring. 

 Clupea harengus harengus L. Fish. Bull. U.S. 71:125-134. 



1977. Occurrence of piscine erythrocytic necrosis (PEN) in 

 the blood of the anadromous aXevjiie, Alosa pseudoharen- 

 gus, from Maine coastal streams. J. Fish. Res. Board 

 Can. 34:281-286. 



Walker. R. 



1971. PEN, a viral lesion offish erythrocytes. Am. Zool. 

 11:707. 



Walker, R.. and S. W. Sherburne. 



1977. Piscine erythrocytic necrosis virus in Atlantic cod. 

 Gadits morhua, and other fish: ultra-structure and dis- 

 tribution. J. Fish. Res. Board Can. 34:1188-1195. 



Stuart W. Sherburne 

 Laurie L. Bean 



State of Maine Department of Marine Resourees 



Fisheries Research Station 



West Boothhay Harbor. ME 04575 



A SIMPLE METHOD TO OBTAIN SERUM 

 FROM SMALL FISH 



It is desirable to obtain blood serum information 

 from small fish due to their extensive use in pol- 

 lutant and disease studies (Snieszko et al. 1969; 

 Snieszko 1974; Mulcahy 1975). It is well known 

 that gross observations cannot detect subtle 

 changes in blood chemistry caused by environ- 

 mental factors such as stress, diet, or inflamma- 



tion (Mulcahy 1975) and some pesticides (Walker 

 1963). 



Techniques to obtain fish blood for study have 

 been described in reviews by Hesser (1960) and 

 Blaxhall (1972). Cardiac and venous puncture are 

 the most commonly used techniques for fish >150 

 mm, while severance of the caudal peduncle and 

 insertion of a capillary tube to draw blood is usu- 

 ally employed for smaller fish. Fish <60 mm pre- 

 sent problems because the quantity of blood ob- 

 tainable is small (generally <0.2 ml), coagulation 

 time is quick, and tissue fragments or clots can 

 clog collecting tubes, causing loss of serum in the 

 transfer from one container (or collecting tube) to 

 another for centrifugation. In most cases an- 

 ticoagulants are used to eliminate some of these 

 problems. 



Sodium oxalate, heparin, or dipotassium ethyl- 

 enediaminetetraacetate (EDTA) are the most 

 commonly used anticoagulants. Unfortunately, 

 oxalate and EDTA anticoagulants can interfere 

 with serum ion determinations, such as calcium, 

 and produce misleading data (Tietz 1976). When 

 many blood serum components are to be mea- 

 sured, especially on instrumentation such as an 

 amino acid auto analyzer, a quantity of serum (at 

 least 0.5 ml and preferably free of anticoagulant) 

 must be obtained for the numerous tests these 

 analyzers can do. Heparinized tubes, excellent for 

 single serum component tests, are limited because 

 the volume of serum they can obtain is generally 

 not enough for use with sophisticated instrumen- 

 tation. This note describes a simple method to 

 obtain pooled serum samples, without anticoagu- 

 lants, from fish <60 mm when hepau-inized tubes 

 are not practical. 



Materials and Methods 



Small fish <60 mm fork length should be anes- 

 thetized, if desired, and blotted to remove excess 

 water on the fish's body. A dry Kimwipe' is wrap- 

 ped around the fish, covering the vent to prevent 

 contamination of the sample, leaving approxi- 

 mately 2.5 cm of the tail exposed (Figure IB). A 

 small portion of the Kimwipe is allowed to overlap 

 the fish's head. The caudal peduncle is severed 

 with sharp scissors, leaving a slight point at the 

 caudal region (Figure IC). The fish is rapidly in- 



' Reference to trade names does not imply endorsement by the 

 University of Southern Mississippi or by the National Marine 

 Fisheries Service, NOAA. 



FISHERY BULLETIN: VOL, 77, NO 2. 1979 



509 



