Longevity and Mortality Rates of Fish in Nature 147 



and Lovettia seali of the salmonoid family mentioned above, 

 Hypomesus olidus, the pond smelt, another of the salmonoids, 

 and the dwarf sea-horse {Hippocampus hudsonius), to over 80 

 years in the Lake sturgeon {Acipenser fulvescens). The maxi- 

 mum recorded age we have found is, in fact, for this latter 

 species (Anonymous, 1954), a specimen 206 cm. long taken in 

 an Ontario lake having been assigned an age of 152 years by 

 examining the structure of the pectoral fin-ray. While it is 

 quite possible that the precise age of such a fish cannot reliably 

 be determined in this way, the work of a number of authors 

 on the longevity of this and related species of sturgeon is con- 

 sistent in showing that they can live to a great age, and it is 

 indeed not unlikely that the occasional truly centenarian 

 sturgeon is still to be found in the more remote water basins 

 as yet untouched by man. Apart from sturgeon and the 

 whitefish mentioned above, other long-lived species include 

 the Arctic char {Salvelinus alpinus; Grainger, 1953) and the 

 halibut (Hippoglossus spp.); whitefish and char are both 

 salmonoids, but sturgeon and halibut are of different sub- 

 orders, so that neither of the extremes of lifespan in fish are 

 confined to a particular taxonomic group. 



In compiling the data on maximum age in Table I we have 

 not used the records for fish in captivity, of which a recent 

 summary is included in the longevity data given by Brown 

 (1957) and further data are presented to this colloquium by 

 Nigrelli. There is nevertheless a broad agreement between 

 the records from the two sources, and the few instances in 

 which there is reason to believe that the entry in Table I may 

 be substantially below the true maximum age of the species 

 are noted in the legend to that Table. 



Size and growth 



Longevity and body sizes are known to be associated in 

 higher vertebrates, especially in mammals (e.g. Sacher, this 

 volume), so that it is of interest to see to what extent the 

 same is true of fish. The growth cycle in fish is, however, more 



