At the risk of sounding cliche and in a manner most routine, it’s difficult not to admit the prowess and remarkable work that Bali Aquarich has accomplished. Founded by Su Wen-Ping, this Bali based aquaculture company has won the world over with their stunning high quality designer clownfish, and yet again with their incredible repertoire of angelfish successes. It’s quite hard to imagine that Mr Su’s virgin dabble into angelfish territory began just a mere three years ago with the successful spawning and raising of Pomacanthus annularis.
Fast forward to 2015, his accomplishments have increased multiples folds to include a ridiculous list of species. In fact, it hasn’t even been two months since our last in-situ report on Mr Su’s Holacanthus passer success and already a brand new angelfish has taken top spot. Apolemichthys trimaculatus was revealed two weeks ago to be the sixth species under Bali Aquarich’s belt. While all of that has been going on, a secret seventh species has been under careful watch and finally after ~150 days of waiting, Bali Aquarich has decided to release news of the first ever Pomacanthus imperator x P. annularis hybrid to be spawned and raised in captivity.
Both Pomacanthus annularis and P. imperator are common and widespread species that overlap significantly in the Indo-Pacific. The latter has a wider distribution that extends to the Indian Ocean as well as a few oceanic islands in the Pacific. While P. imperator has been reported to hybridise with P. semicircularis as well as P. chrysurus in the wild, there has only ever been one dubious record of a cross with P. annularis. Aside from that anomalous report, Pomacanthus annularis is not known to hybridise with any other species.
It only comes as a mild surprise actually that Bali Aquarich managed to pull this one off. It was only a matter of time, and the more pressing question was “when”? Throughout the three years that Pomacanthus annularis have been in production, the adult broodstock pairs were housed in the same quarters with another angelfish. No prizes for guessing which – Pomacanthus imperator. Yet despite the large success and relative ease of raising the former, nothing ever came out of P. imperator despite regular signs of courtship. The males of P. imperator display a rather beautiful purple hue on its face during nuptial advances, and this inadvertently alerted Mr. Su that at least something was going on with the pair, although whether or not spawning took place was a different question.
The beginning of this year saw a significant change in progress with regards to the imperator front. Hidden amongst the batch of regular P. annularis offspring lay a few unusual oddities. While it isn’t uncommon to find aberrations in the barring of captive bred angelfish, a few of these had patterns that were more convoluted than usual. Still, not much thought was given to it and they were just simply left to develop amongst the regular P. annularis brood.
Like a cliche storybook chapter, it was by sheer coincidence or just dumb luck that Mr. Su chanced upon his P. imperator pair spawning not long after. Eggs were collected and attempts at rearing them were carried out, but due to the relatively small egg size, no success has been attributed to this species yet. P. annularis on the other hand has a larger egg diameter, measuring in at 0.9mm.
So now it was finally known that the imperators have been spawning along side the annularis angels, but for how long? Even so, seeing as eggs were collected and raised under the conditions best suited for P. annularis, none of the P. imperators would have survived anyway due to the large difference in egg sizes and suitability of first foods.
While P. imperators were definitely not being raised successfully, the incidence of spawning in the same system as P. annularis could bring up a potential platform for hybridisation, and this sparked the frantic witch hunt for all oddly designed “P. annularis“. True enough, the juveniles with unusual striations that were once looked over were now being separated in hopes that they will one day grow up to show traits of P. imperator.
It’s interesting to note that because the size difference of eggs between the two species prevented imperator eggs from hatching and growing when raised under those conditions, we’re able to know therefore that the mother of this hybrid is P. annularis while the father is P. imperator.
The concentric ring markings of juvenile imperators are very distinctive, but in juvenile hybrids and especially captive bred angels, distortion and unusual manifestation of barring occur so frequently that it is difficult to say without a shadow of a doubt that the occurrence is due to genetic input of P. imperator. P. imperator however, leaves more than one marker for identification of their young, and it is the presence of chain like bubbles that rim the edges of the dorsal and anal fins.
The suspected hybrids were screened for the presence of these traits, and like the individual above, more than one were inevitably found. When asked if these were the results of accidental or deliberate spawning, we were told with much surprise that these were deliberate. We were quite sure that these hybrids arose from accidental mixing of gametes from the separate spawning of the two parent species in the same system, but Mr. Su said otherwise. While same species pair spawning occurred regularly, he observed on a few occasions the two species splitting up to spawn wilfully. Strangely and interestingly enough, this did not happen when individuals of P. imperator and P. annularis were paired off in separate systems, and the spawning only occurred when both pairs were present together.
Julian Sprung suggested that social barriers may break down when pairs are present, in the same way Pomacanthus in Southern Florida form groups during spawning season. Although we’re still not entirely sure why P. imperator and P. annularis only spawn when pairs of both species are present, the hypothesis does not seem farfetched and quite plausible.
It has been approximately a hundred and fifty days and the hybrids are now large enough to show characteristic traits of P. imperator. The transitioning pattern is also starting to emerge from under the juvenile white striations, and it is completely different from P. imperator or P. annularis at the same life stage. How this fish will turn out as an adult is a complete guessing game at this point. It’s also interesting to note that the hybrids grow at a significantly faster rate than the regular P. annularis. It’s not so evident in the photos, but they are at least 1.5x larger but were raised in the same conditions and fed the same food.
Tragically, it comes as rather sad and unfortunate news that this is the only surviving hybrid offspring, and also the sole survivor to its parents. In a tragic workplace related human error, both broodstock pairs of P. imperator and P. annularis were lost, after eight years of captivity.
The entire batch of hybrid as well as P. annularis offspring also suffered heavy losses, and while most of the P. annularis juveniles were salvaged, only one hybrid survived. It’s highly unfortunate, and almost cruel how a hybrid breakthrough stops here, right at the precipice of marketing for the masses. Perhaps the silver lining here is the success, knowledge and experienced gain, but for Mr. Su to recreate this miracle baby again would see him starting from scratch. New broodstock parents of P. imperator and P. annularis would have to be procured.
It comes as no surprise then that this one-off hybrid is not for sale, and now lives to swim in one of the many vast marine ponds of Bali Aquarich in hopes that it lives to a ripe old age to forever preserve its parents legacy. Big thanks to Mr. Su for the usual hospitality, and Vincent Chalias for the photos above.