SHORT COMMUNICATION THE SPLEEN IN HYPOXIC AND EXERCISED RAINBOW

• Main Authors: R. M. G. Wells, R. E. Weber
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1990
• Subjects: Randall; Icefish
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.543.82; http://jeb.biologists.org/content/150/1/461.full.pdf

The teleost spleen is a discrete organ containing, in addition to erythrocytes sequestered from the circulation, erythropoietic tissue involved in the synthesis of new erythrocytes. In this division into supply and synthesis, there appear to be some species differences. The eel spleen is an erythrocyte reservoir but is not thought to be a major erythropoietic organ (Johansson-Sjobeck, 1979). The splenic mass in goldfish does not change with induced anaemia (Houston etal. 1988). The trout spleen, in contrast, plays an erythropoietic role during anaemia (Lane, 1979), in addition to serving as a store of erythrocytes (Randall and Daxboeck, 1982). Exercise in trout is accompanied by haemoconcentration (Black etal. 1966; Stevens, 1968) and the spleen appears to contribute to elevated circulating haemoglobin levels (Stevens, 1968). Capture stress induced a 25% reduction in spleen haemoglobin concentration, [Hb], in the marine teleost Girella tricuspidata, and splenic histology revealed melano-macrophagic centres and erythropoietic tissue indicative of a major role in erythrocyte destruction and synthesis (Ling, 1984). Neither role can be played by the spleen of the icefish, which lacks haemoglobin (Wells et al. 1990). Although storage and synthesis of erythrocytes in the spleen have been examined in few fish, several intraspecific factors affect the size of the spleen. These include reproductive status and body weight (Yamamoto and Itazawa