cohort  larval_age  length_mean  Mg_to_Ca  Sr_to_Ca  C_pcnt  N_pcnt  
May     5           77           1.11      1.66      12.13   0.013   
May     8           81           0.92      1.72      12.16   0.013   
May     11          89           0.86      1.72      12.15   0.02    
May     13          106          0.83      1.73      12.2    0.023   
May     15          126          0.79      1.77      12.16   0.023   
May     17          135          0.86      1.82      12.33   0.024   
May     19          144          0.6       1.8       12.57   0.025   
Aug     1           76           0.79      1.62      12.47   0.009   
Aug     3           83           0.72      1.55      12.34   0.018   
Aug     5           90           0.64      1.59      12.22   0.017   
Aug     7           92           0.76      1.66      12.22   0.02    
Aug     9           99           0.63      1.67      12.23   0.02    
Aug     11          122          0.74      1.67      12.35   0.023   
Aug     13          125          0.66      1.65      12.33   0.02    
Aug     15          151          0.61      1.68      12.27   0.025   
Aug     17          167          0.66      1.68      12.24   0.03    
Aug     19          182          0.73      1.69      12.29   0.029   
Aug     21          196          0.89      1.72      12.41   0.031