  We study the Howe correspondence for unipotent representations of irreducible
dual pairs $(G',G)=(\text{U}_m(\mathbb{F}_q),\text{U}_n(\mathbb{F}_q))$ and
$(G',G)=(\text{Sp}_{2m}(\mathbb{F}_q),\text{O}^\epsilon_{2n}(\mathbb{F}_q))$,
where $\mathbb{F}_q$ denotes the finite field with $q$ elements ($q$ odd) and
$\epsilon=\pm 1$. We show how to extract extremal (i.e. minimal and maximal)
irreducible subrepresentations from the image of $\pi$ under the correpondence
of a unipotent representation $\pi$ of $G$.
