The Biology of Senescence 



found to live the longest, sometimes to the fortieth year. But the 

 carp, bream, tench, eel and the like are not held to live above 

 ten years. Salmon grow quickly and live not long, as do also 

 trout; but the perch grows slowly and lives longer. How long 

 the breath governs the vast bulk of whales and orcae, we have 

 no certain knowledge; neither for seals, nor for innumerable 

 other fish' x {Hist. Vitae et Mortis) . Most of these figures are 

 reasonably congruent with Flower's list. 



2-2-6 INVERTEBRATES 



Previous lists of invertebrate longevities {Tabulae Biologicae; 

 Heilbrunn, 1943; Nagornyi, 1948, etc.), apart from the excellent 

 data collected by Weismann (1891), almost all spring directly 

 from the opinions of Korschelt (1922). These are based on data 

 from the older literature, largely unsupported by exact refer- 

 ences, some accurate, but others highly speculative. The type 

 of evidence which has got into such lists is well exemplified by 

 the 15-20 year life-span of the crayfish. This, though probably 

 correct, appears to owe its origin to an aside by T. H. Huxley 

 (1880) to the effect that 'it seems probable that the life of these 

 animals may be prolonged to as much as fifteen or twenty 

 years' {The Crayfish, p. 32). The large Tridacna may in fact be 

 the longest-lived invertebrate, in view of high records of age in 

 much smaller pelecypods, but the literature contains no in- 

 formation of any description about its life-span, and the rela- 

 tionship between great size and great age is perpetually being 

 disproved in other animals. Of a supposedly 18-year-old Helix 

 pomatia Korschelt writes elsewhere: 'Gewiss hat diese Angabe 

 von vornherein wenig Wahrscheinlichkeit fur sich, aber als 



1 'Piscium vita magis incerta est, quam terrestrium, quum sub aquis 

 degentes minus observantur. . . . Delphini traduntur vivere annos circa 

 triginta; capta experimento in aliquibus a cauda precisa; grandescunt 

 autem ad annos decern. Deprehensae sunt aliquando in piscinis Caesarianis 

 muraenae vixisse ad annum sexagesimum. Certe redditae sunt longo usu 

 tarn familiares, ut Crassus orator unam ex illis defleverit. Lucius, ex 

 piscibus aquae dulcis, longissime vivere reperitur; ad annum quandoque 

 quadragesimum ... at carpio, abramis, tinea, anguilla et huiusmodi non 

 putantur vivere ultra annos decern. Salmones cito grandescunt, brevi 

 vivunt, quod etiam faciunt trutae; at perca tarde crescit, et vivit diutius. 

 Vasta ilia moles balaenarum et orcarum, quamdiu spiritu regatur, nil 

 certi habemus; neque etiam de phocis. . . . et aliis piscibus innumeris.' 



54 



