Scientists believe they found two new species of colorful reef fish and for the first time collected a male Hawaiian pigfish during a 25-day expedition to the Northwestern Hawaiian Islands.

Researchers aboard the National Oceanic and Atmospheric Administration ship Hi‘ialakai used advanced dive technology to survey the deep coral reefs of Papahanaumokuakea Marine National Monument — collecting and filming fish species at far greater depths than possible with conventional scuba gear.

The ship returned Wednesday from the expedition.

A pink basslet with neon accents and a wrasse with purple stripes had never been seen before by divers. Both fish are currently being examined to determine that they are indeed new species.

Researcher and Bishop Museum ichthyologist Richard Pyle, who designed the expedition’s dive gear, said the basslet was the most exciting find.

“Sometimes you see a new species but it’s only a little different from some other thing that lives near it, but this is something brand new, something we never expected to see, so it’s actually very exciting,” Pyle said.

Divers also collected their first male Hawaiian pigfish, known by local fishermen as the “table boss.” Before the voyage only females had been seen and documented.

While holding two frozen Hawaiian pigfish, chief scientist Randall Kosaki pointed out the most notable color difference between the two: red tail for males, yellow for females.

Kosaki described the dive as “kinda like going to the moon” because no human being had ever laid eyes on Papahanaumo- kuakea’s reefs at that depth.

“That’s what’s fun about this job,” he said. “No other human has seen this fish before.”

According to Kosaki, the new species will join the 45,000 specimens that are already a part of the Bishop Museum’s collection.

The collection houses species in alcohol storage jars. They serve as reference specimens used for side-by-side comparison whenever a probable new species is discovered.

This comparison helps scientist determine whether they have discovered a new creature.

“What’s particularly unusual about the basslet is that we only saw a few of them. Usually when you find a new species you can find dozens of them, but this time we only found a few individuals, so it may be that the main populations are much deeper and we’re just seeing a few strays that come up into shallow waters,” Pyle said. “It’s a fish we had no idea existed before this cruise and we’re looking forward to doing future expeditions to try to find out where the population center started.”

Josh Burns, a researcher with the Hawaii Institute of Marine Biology, said those interested in marine research throughout the Hawaiian archipelago can log on to the Coral Health Atlas to see data, displays and videos featuring a 360-degree view of previous dives.

“When I document the research, I always want to make it tangible to people so we try and put all of our products on the website,” Burns said. “All the data we collected on these trips, the models and 360-degree camera imagery, which takes people on an interactive scuba dive, is on there.”

Burns specifically mentioned one video in which he and other divers were caught in a school of 60 Galapagos sharks.

An exhibit at the Bishop Museum will also highlight the Papahanaumokuakea ecosystem. The exhibit, “Journeys: Heritage of the Northwestern Hawaiian Islands,” features an interactive map, a virtual reef dive and a realistic, life-sized Hawaiian monk seal statue.

The exhibit will open Aug. 13 and continue through Jan. 29.

According to Pyle, a new species of butterfly fish discovered on a previous voyage and not yet named will also be on display.

Both the wrasse and basslet discovered during this expedition remain unnamed as well.

Kosaki and Pyle will give the fish a species name using a Latin or Greek root and its specific characteristics.

“The name is based on something descriptive like the color, character or its closest relative, but more commonly people name it after a scientist that helped them or the place it was found,” Kosaki said. “Recently we’ve given some new species Hawaiian names.”

Pyle, who once named a fish after his wife, who rescued him during an expedition, said he’s unsure what the names will be just yet.

“First we have to confirm they are new species. The hard part is figuring out for sure that it’s new, who it’s closest related to and other things that make it a different species. We have to work all of that up, and then the fun part is deciding what the name is.”

He added, “I’m sure we’ll pick something interesting.”