species                     myelin_flag  stage        length_um  length_mm  speed  speed_stdev  
Acartia_tonsa               No           N1           95         0.095      29.8   8.6          
Acartia_tonsa               No           N2           115        0.115      51     7.6          
Acartia_tonsa               No           N3           120        0.12       55     12.7         
Acartia_tonsa               No           N4           135        0.135      60     7.2          
Acartia_tonsa               No           N5           175        0.175      84     11.2         
Acartia_tonsa               No           N6           235        0.235      96     12.3         
Acartia_tonsa               No           C1           300        0.3        158    21.6         
Acartia_tonsa               No           C2           nd         nd         nd     nd           
Acartia_tonsa               No           C3           nd         nd         nd     nd           
Acartia_tonsa               No           C4           nd         nd         nd     nd           
Acartia_tonsa               No           C5           nd         nd         nd     nd           
Acartia_tonsa               No           C6_Male      1030       1.03       432    106          
Acartia_tonsa               No           C6_Fem       960        0.96       372    69