CELL TYPES, DIFFERENTIAL CELL COUNTS, AND 



BLOOD CELL MEASUREMENTS OF 



A PORTUGUESE SHARK, CENTROSCYMNUS COELOLEPIS, 



CAPTURED AT 700 FATHOMS 



Stuart W. Sherburne' 



ABSTRACT 



A Portuguese shark, Ccntroscymniis coelolepix, 620 mm (24.4 inches) in total length 

 captured in a lobster trap 700 fm deep at Hudson Canyon in February 1971 had a 

 mean erythrocyte size of 33.4 X 23.6 n, which is larger than any previously recorded for 

 the class Chondrichthyes. Both neutrophils and heterophils were found in the blood, 

 whereas earlier reports describe only one or the other from the same elasmobranch. 



Most sharks are shallowwater forms, with 

 relatively few representatives from the deeper 

 parts of the ocean. Bigelow and Schroeder 

 (1948:494-499) reported that the Portuguese 

 shark is strictly a deepwater shark, found 

 chiefly in depths greater than 200 fm; it has 

 been recorded down to 1,487 fm. The smallest 

 recorded specimen is about 9 inches long, and 

 the largest, about 44 inches. Off the North 

 American coast it occurs mostly in tempera- 

 tures of 5° to 6°C; off Portugal, between 

 4° and 11°C; and in the Mediterranean, at 

 12° to 13°C. 



Few detailed studies have been made of 

 either the blood or the blood-forming organs 

 in elasmobranchs, probably because of diffi- 

 culty in obtaining the necessary material 

 (Saunders, 1966a). In this report I describe 

 the cell types, differential cell counts, and 

 measurements of both the erythrocytes and 

 leukocytes in the blood of a Portuguese shark, 

 Centroscynuius coelolepis. I report on this 

 specimen because of its unusually large cell 

 sizes in all cell categories. Cell measurements 

 revealed erythrocytes larger than those in all 

 but a few of the vertebrates, and the cells 



' Northeast Fisheries Center, National Marine Fish- 

 eries Service, NOAA, West Boothbay Harbor, ME 04575. 



Manuscript accepted August 1972. 



FISHERY BULLETIN: VOL. 71, NO. 2, 1973. 



appear to be the largest reported for the class 

 Chondrichthyes. 



A search of the literature reveals no previous 

 blood work has been reported on this species. 



MATERIALS AND METHODS 



The Portuguese shark examined for this 

 report was a female, 620 mm (24.4 inches) 

 in total length, and was captured in a lobster 

 trap 700 fm deep at Hudson Canyon on 21 

 Febi-uary 1971. 



Smears were made with blood obtained by 

 direct heart puncture of the live shark. A 

 small incision was made over the heart area 

 through which a heparinized capillary tube 

 75 X 1.1-1.2 mm was inserted into the heart 

 and allowed to fill three-quarters full. A small 

 drop of blood from the tube was placed on a 

 microscope slide, the tube sealed with plastic 

 clay and the smear made. Three capillary 

 tubes were used to make four blood smears 

 and the microhematocrit determination. The 

 sealed tubes were centrifuged for 3 min at 

 11,000 rpm. Both a microcapillary reader 

 and a millimeter rule were used in measuring 

 the packed red cell volume, buffy coat, and 

 plasma volumes. 



The slides were air-dried and stained with 

 Wright's and with Wright's and Giemsa's 

 stains, and the staining times were varied. 



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