I may have a chance to visit again this Fall, but I forgot to post my overall impressions from when I visited this past July:
Honestly, I only visited for the Abei Angelfish (Centropyge abei) which at the time, was the only one in a public aquarium (now it's #2 since Steinhart in San Fransico has one). Overall, the place isn't very big and not that great in terms of species. Historically, the facility has been known to house some of the rarest, mainly Mesophotic species in the past years but that's greatly diminished. They use to have Hawaiian Yellow Anthias (Odontanthias fuscipinnis), Pete's Butterflyfish (Prognathodes basabei), and Sunrise Hogfish (Bodianus sanguineus) in a very cool Twighlight Zone themed tank a few years ago but it was replaced with a low-light, volcano style tank with generic species so I didn't get a chance to see it.
The Aquarium still has it's handful of rare species, such as the Masked Angelfishes (Genicanthus personatus), Bandit Angelfishes (Apolemichthys arcuatus), and Hawaiian Morwong (Goniistius vittatus, possibly the only one in captivity). All of which are incredibly old, I believe most are over 15 years of age (The Abei is 18 / 19)
They do have the Weedy Seadragon's and White's Seahorses which are also uncommon, but that's about it. The predator tank isn't very impressive, I'm not sure how their Zebra Shark ended up there but I'd like to see it in a larger tank honestly.
They still had a sign for a Smith's Butterflyfish (Chaetodon smithi) which would make it the only one in a public aquarium (maybe even captivity), however like a lot of other species, wasn't present in the aquarium. Which really sucks since they had some cool stuff like Hawaiian Wire Coral Gobies and Wire Coral Shrimp signed I would've loved to see, but their tank was empty.
Also their Hawaiian Monk Seal to my knowledge is still in California at UC Santa Cruz's (?) Marine Mammal facility.
Overall, I liked the Maui Ocean Center much more (deserving of the self proclaimed "Aquarium of Hawaii" title they have). If you're a fish nerd, I'd still recommened checking the place out, since a lot of the deepwater species are Hawaiian Endemic so it'll be very rare to see them outside of Hawaii. And the Bishop Museum not too far away does have their pair of Pete's Butterflyfishes so it's not a huge loss. But if you're expecting a place you can spend half the day it, it's more so a 30 minute to hour long stop and then you can check out the other areas of the area which are a lot of shops and tourist stuff.
