Physiology of Marine Teleosts. II. Hematologic Observations

Haematological characteristics of albacore, Thunnus alalunga (Bonnaterre), and skipjack, Katsuwonus pelamis (Linnaeus)

“…While a direct comparison with published differential counts is difficult, our differential counts are generally consistent with those reported in the literature. The high lymphocyte counts we found in albacore and skipjack agree with results reported for bluefin tuna (Becker et al, 1958), little tuna (Saunders, 1966), mackerel (Becker et al, 1958;Pitombeira & Martins, 1970) and other teleosts (Watson et al, 1963;Mulcahy, 1970;McCarthy et al, 1973, 1975, andothers). The increase in circulating eosinophils observed over time in the restrained, immobilized albacore is similar to findings made by Gardner & Yevich (1969) who noted increases in eosinophil levels over time in Fundulus heteroclitus, which the authors judged were stressed because the fish were held in small aquaria.…”

“…Basophils were not observed in either albacore or skipjack, which is in agreement with earlier observations on skipjack (Saito, 1954;Saunders, 1966), little tuna (Saunders, 1966), and yellowfin tuna (Saito, 1954). This observation also agrees with Becker et al (1958) who did not observe basophils in bluefin; however, it does not agree with Gutierrez (1967), who reported basophils to be the smallest and most scarce of the granulocytes present in bluefin tuna. It is possible that basophils could be present in low numbers in the peripheral circulation of albacore and skipjack, yet not be in the smears which we examined.…”

“…A selected review of recent literature reveals that some authors include thrombocytes in differential white cell counts (Boyar, 1962;Saunders, 1966;Gardner & Yevich, 1969;Sherbourne, 1973;McCarthy, Stevenson & Roberts, 1973, 1975 while others do not (Becker et al, 1958;Watson et al, 1963;Colgrove, 1966;Pitombeira & Martins, 1970;Blaxhall, 1972;Conroy, 1972). We have followed the convention used in mammalian studies and did not include thrombocytes in the differential white cell counts.…”

“…These reports deal primarily with haemoglobin values (Klawe, Barrett & Klawe, 1963;Barrett & Williams, 1965), packed cell volumes (Saito, 1954(Saito, , 1959Magnuson, 1969), and types and migration of haemoglobins (Sharp, 1969(Sharp, , 1973(Sharp, , 1975. Published information concerning leucocytes in tunas include a description of bluefin tuna, Thunnus thynnus, white cell morphology (Gutierrez, 1967) and cell count (Becker et al, 1958), and tables containing differential counts for skipjack, little tuna, Euthynnus alleterattus, and yellowfin tuna, Thunnus albacares (Saunders, 1966;Saito, 1954). This paper will report haematological results observed as part of an investigation of albacore and skipjack tuna physiology and biochemistry.…”