You can pull out your words into an array by using captures in a global match, like this

use strict;
use warnings;

my $restOfLine = q{one fish two fish red fish blue fish};

my @words = $restOfLine =~ m{(\S+)\s+fish}g;

print qq{$_\n} for @words;
[download]

which produces

one
two
red
blue
[download]

I hope this is of use.

Cheers,

JohnGG