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Our next story takes us behind the scenes at an aquarium, where staff members have reared a special kind of fish for the first time. Science reporter Ari Daniel says this colorful little thing may hold broader lessons for raising other marine life in captivity.
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ARI DANIEL, BYLINE: On the lower level of Chicago's Shedd Aquarium, inside the wild reef exhibit, sits a small tank containing two warty frogfish. Each one's about the size of a tennis ball.
JENNY RICHARDS: These are very globular looking fish. It is comically round (laughter).
DANIEL: They're yellow with splashes of red, says senior aquarist Jenny Richards.
RICHARDS: And they have a bunch of bumps all over their body, which is where they get the warty frogfish name. I definitely think they look cute.
DANIEL: Cute but cutthroat - part of its dorsal fin is a lure that looks like a little shrimp, which it uses to attract its prey. Last year, the female in the tank began to look kind of bloated, and then in September, she released a raft of tens of thousands of translucent eggs, which the male then fertilized.
RICHARDS: Our wild reef aquarist quickly grabbed it and brought it up to our larval systems for us to attempt to raise.
DANIEL: But to Richard's knowledge, no one had ever reared baby warty frogfish before.
RICHARDS: It was definitely a little nerve-racking trying to make sure that we made the most of this rare opportunity.
DANIEL: The team did have a lot of experience raising all sorts of other fish, but each species has its own specific needs and requires mimicking their open ocean environment in a small 15-gallon tank.
RICHARDS: We have to be able to have the right lighting conditions, the right flow conditions, the right temperature and provide the right diet.
DANIEL: So Richards and her team took it slow. Within a few days, thousands of tiny larvae had hatched out.
RICHARDS: They're incredibly fragile. They look very similar to a tadpole.
DANIEL: The aquarists focused their efforts on 500 of them. They fed them tiny crustaceans called copepods at first, and gradually the larvae underwent a series of dramatic changes. Their vertebrae and fins shifted position. Their muscles changed, and with each transition, the ranks thinned until there were only three remaining.
RICHARDS: If they looked like they were stressed out from too much light, we lowered the light levels. If it looked like they were struggling to swim, we decreased the flow. So just making tiny adjustments to try to make sure that they looked healthy.
DANIEL: It's really tender work.
RICHARDS: Yes.
DANIEL: Ultimately, around Day 90, just one larva transitioned into a juvenile - a pea-sized version of the adult - bright yellow, orange freckles, its own little lure - kind of like a small, fishy Pokemon. Richards says this one juvenile warty frogfish, which she named Domino, is a big achievement.
RICHARDS: This could help us with raising other species in the future. With changing oceans, climate change, being able to raise these species in captivity is becoming increasingly important.
DANIEL: The Shedd Aquarium isn't unique in this pursuit. Nicole Rhody helps manage aquaculture research at Mote Marine Laboratory in Sarasota. She applauds the Chicago team's accomplishment.
NICOLE RHODY: You know, it's something to celebrate because it's really not easy to do because you're essentially trying to take, you know, what happens in nature and be able to recreate that.
DANIEL: Rhody's impressed by how quickly they succeeded based on her work trying to rear the common snook, a big-deal sportfishing species.
RHODY: And man, I probably spent probably 15 years of my life working on that animal trying to close the life cycle before we were able to do it.
DANIEL: But she says it's worth the effort for conservation purposes and to support commercial and recreational aquaculture. Back at the Shedd Aquarium, Jenny Richards stands beside Domino's tank in a spot just for staff.
RICHARDS: He's kind of hiding, but he's in that purple plant. We're definitely a little attached to the baby.
DANIEL: Richards says she looks forward to the day when Domino can go on exhibit and be seen by the public - a tiny testament to what's possible.
For NPR News, I'm Ari Daniel.
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