Vital Rates (Life History Parameters)
of the Salmon shark Lamna ditropis Hubbs & Follett, 1947


Parameter Female Male References
Largest specimens ~3.05 m TL, annectotal accounts mention 3.7 - 4.3 m TL   Compagno (2001)
Size at maturity 221 m TL (8-10 years) 1.82 m TL Compagno (2001) based on Tanaka (1980)
Smallest mature      
Largest immature 2.1-2.2 m TL 2.1-2.2 m TL Compagno (2001)
Sizes at which 10, 50, and 90% are mature (c)      
Age at maturity

8-10 years;
6-9 yr (median precaudal length of 164.7 cm PCL)

5.0 yr;
3-5 yr (median precaudal length of 124.0 cm
PCL).

 Compagno (2001) based on Tanaka (1980);
Goldman and Musick, Fish. Bull. 104:278–292 (2006)
Longevity estimate > 20 years >27 years Compagno (2001)
Gestation time estimate 9 months Compagno (2001)
Reproductive cycle 1 year Compagno (2001)
Littersize (# of pups per litter) 2-5 Compagno (2001)
Birth size estimate 0.60 m TL Compagno (2001)
Elasticity pattern using mean Abar / alpha = 1.3 from 60 elasmosbranchs (Mollet 2002, AES Manaus) with alpha = 9y;,
Abar = 11.7 yr; and
GP = 0.75 yr.

Normalized Elasticities:
E(m) = 1 / (Abar + 1) = 1/12.7 = 7.9%;
E(JS) = (alpha - GP) / (Abar +1) = 65.0%;
E(AS) = (Abar - alpha + GP) / (Abar + 1) = 27.2%.

 

Mollet 2003 (AES Manaus)
Normalized elasticities based on Abar = 12.335 yr [from LHT or Leslie matrix with alpha = 9 yr, maximum age 25 yr, mortality = - ln(0.01)/25, m = 4/2 = 2]:
E (fertility) = E(m)  = 7.5%;
E(juvenile survival) = E(JS) = 61.9%;
E(adult sruvival) = E(AS) = 30.6%

Using alpha = 7.5 yr (mean value in Goldman and Musick 2006), Abar/alpha = 1.3 (i.e. Abar = 9.75 yr), GP = 0 yr (i.e. neglecting GP complication) and we get:
E(m) = 1 / (Abar + 1) = 1/10.75 = 9.3%;
E(JS) = (alpha ) / (Abar +1) = 69.8%;
E(AS) = (Abar - alpha) / (Abar + 1) = 20.9%

.

 

 
Parameter Female Male References
Created March 2003, updated April 2007; Back to previous page
Please send comments or corrections to mollet@pacbell.net