\begin{longtable}{| X | X | X | X | X |}
  \caption{A properly formatted traits file}\label{tab:traits} \\
  \toprule
  & Trait1 & Trait2 & ... & TraitM \\
  \midrule
  Strain1 & 1 & 0 & ... & 1 \\
  Strain2 & 1 & 0 & ... & 0 \\
  Strain3 & 0 & 0 & ... & 1 \\
  ... & ... & ... & ... & ... \\
  StrainN & 1 & 0 & ... & 0 \\
  \bottomrule
\end{longtable}