List of bioluminescent plants and animals HERE.
Single celled organisms:
*Coelenterates and Ctenophores (jellyfish): siphonophores, medusae, soft corals, (comb jellies)
Gastropods: nudibranchs (rare), clams (rare), *squids, octopus (rare)
Annelids (worms): *polychaetes (bristle worms), earthworms
*Marine crustaceans: mysids (rare), copepods, ostracods (firefleas), amphipods, krill, shrimp
Insects: *beetles (fireflies, glowworms), flies (rare), centipedes (rare), millipedes (rare)
Echinoderms:, sealilies, seastars, *brittlestars, sea cucumbers
*Tunicates: pyrosomes, larvaceans
*Fishes - many different types
For a more detailed list visit the Bioluminescence web site.
however, if Middle Earth is New Zealand, the source of the light might have been the Waitomo glowworms.