Capping off a week of claiming species firsts, starting with the successful breeding of Potter’s Angelfish and then the breeding of the Lemon Butterflyfish, Rising Tide Conservation is bringing it home with the last piece of the Hawaiian endemic trifecta. Avier J. Montalvo, working at the Oceanic Institute, has produced the world’s first captive-bred Hawaiian Cleaner Wrasse, Labroides phthirophagus. I spoke with Montalvo last night, and he’s already done it again, producing a second group of four juveniles.
Throughout the day, Rising Tide has released the story of Montalvo’s success through social media channels. Here’s their story, told in the captions of each photo.
Rearing By Accident
About three years ago, I reported on the world’s first captive-bred Cleaner Wrasse, Labroides dimidiatus. This occurred at Bali Aquarich under Wen-Ping Su, and it was quite literally a happy accident, as the eggs were collected alongside the target species (an Angelfish) and were simply reared by accident. Given the low cost of this species as a wild-sourced fish, it should be no surprise that Bali Aquarich didn’t pursue this success further, and to the best of my knowledge no captive-bred Cleaner Wrasses were ever made available to the aquarium trade.
In what is almost too coincidental to be ironic, it’s interesting to highlight that once again, this sibling species, the Hawaiian Cleaner Wrasse, wasn’t exactly reared out of a targeted breeding effort. Rather, they’ve simply been one component of the cumulative nightly spawn collected out of a large display aquarium that houses many different families of pelagic spawning reef fishes. So it wouldn’t really be a stretch to suggest that, once again, another Cleaner Wrasse breeding first has happened almost by accident!
Redefining a Species Through Culture
For Montalvo, his roots as an aquarium hobbyist are revealed by what he finds most compelling about the work.
Montalvo found the rearing of the Hawaiian Cleaner Wrasse noteworthy due to what he called a “short pelagic larval duration, very short in comparison [to the other fishes I’ve recently raised].” He continued, “[This is the] first wrasse I found [to settle] much earlier than the others.”
Generally speaking, marine fish breeders find fishes with shorter larval durations faster-growing and easier to rear; they simply spend less time in the more problematic pelagic phase of their lifecycle.
“Evidently, they don’t need to clean,” remarked Montalvo, addressing their reputation as obligate cleaners. “They don’t need to clean at this age, or at least up to this point in rearing. We know they’re not likely going to clean other larvae, but it’s unclear at what stage any nutrients provided by ‘cleaning/grazing’ would be ‘essential’ for optimum health. So, they may need to clean at some point…at least to live up to their name.”
When pressed to ask what these fish are feeding on, Montalvo didn’t hold back. For larval rearing, Montalvo knows they ate copepond nauplii and rotifers, because otherwise, “[the juvenile wrasses] wouldn’t exist.” Talking about the now-settled juveniles, Montalvo reports that, “The first individual started eating enriched artemia, Cyclop-Eeze, and flake. These next four I have on Cyclop-Eeze and Otohime. They have eaten pretty much everything.”
The diet of these young captive-bred wrasses is notable. According to Montalvo’s assessment, he fully believes that the Hawaiian Cleaner Wrasses would be “able to survive in captivity if they can actually be reared or trained to accept conventional aquaculture food items in addition to what nutrients they would receive from ‘cleaning.'”
Clearly, captive-breeding can redefine the aquarium husbandry of this species, as breeding has done for many other species in the past. Wild-collected seahorses are a great example, as they are reluctant to accept anything other than live feeds, while their captive-bred offspring can be gluttonous consumers of frozen shrimp! For a species that has “best left in the wild”-type recommendations surrounding it, the notion of a captive-bred Hawaiian Cleaner Wrasse that eats anything you throw in the tank–with gusto, no less–represents a completely fundamental shift (I hate to invoke the overly-used phase “game-changing,” but that’s truly what this is).
Wild-caught Hawaiian Cleaner Wrasses will always be a challenge, but with dedicated breeding efforts, this beautiful species could become a highly accessible aquarium inhabitant for almost any aquarist. All it takes is the effort, and the market demand to support that effort.
So, captive-bred, easy-to-feed Hawaiian Cleaner Wrasses everywhere in two weeks, right?
Not quite. “This is all baseline work…I think more work needs to be done for sure,” wrote Montalvo. Reflecting on the week’s news, “I want brood fish of all these species,” he mused, “to perfect and refine.”
This success means different things to different people. For Dr. Chad Callan, Director of the FinFish Program for the Oceanic institute of Hawaii Pacific University, it means further proof that the techniques his team developed to rear the world’s first captive-bred Yellow Tangs indeed work for other marine ornamental fish species. Dr. Judy St. Leger, President of Rising Tide Conservation and Vice President for Research and Science at SeaWorld Parks & Entertainment, sees the ability to propagate this species as an important conservation tool, given the restricted range of this Hawaiian endemic. For this author, it means a lot of the talking points surrounding both an impossible-to-keep species and the aquarium trade in Hawaii that supplies this species, are being redefined (see the op-ed, Hawaiian Cleaner Wrasse is Rising Tide’s Mic Drop).
Credits: From materials released by Rising Tide Conservation / Avier J. Montalvo