A pair of juvenile female Genicanthus watanabei at 87 days post hatch, bred by Karen Brittain in Kailua, Hawaii.

Karen Brittain scores a first with Genicanthus watanabei

Excerpt from Reef News, CORAL January/February 2013

One of the breeding milestones of 2012 is the recent news that marine fish breeder Karen Brittain has achieved the first confirmed captive culture of Watanabe’s Angelfish, Genicanthus watanabei, spawned and reared successfully in Hawaii.

Genicanthus watanabei is the second Genicanthus species to be captive-bred; the first was G. personatus, the Hawaiian Masked Angelfish, which was raised more than 10 years ago at the Waikiki Aquarium—also by the talented Brittain, a biologist at the Hawaii Institute of Marine Biology at the University of Hawaii in Honolulu. She is the only aquarist in the world known to have successfully bred any marine angelfish from this coveted genus.

Brittain’s passion for experimenting with rearing larval marine aquarium fishes has remained strong in the last decade. She continues to work with several species in her free time at her home in Kailua. Brittain frames her work as “an effort to increase the availability of captive-reared fish species to the aquarium industry,” and her success is demonstrated by the continued routine availability of the perfectly striped captive-bred Latezonatus Clownfish (Amphiprion latezonatus) she has bred at home (see “Latezonatus Lust,” CORAL July/August 2011).

The larval run that produced these G. watanabei was Brittain’s fifth try with this species since the broodstock began spawning in June 2012. The winning run started on September 8, 2012, and lasted into December 2012. Spawned eggs were 800 microns in diameter and hatched in 19 hours at a temperature of 77ºF (25ºC).

Pre-juvenile Watanabe Angel exhibiting characteristic yellow coloration.

The larvae started eating on day 4 post hatch and were fed wild plankton supplemented with rotifers, cultured copepods, and Artemia. They went through many different stages of development and finally exhibited benthic behavior, settling to the bottom at 57 days old. Full metamorphosis started at 82 days, when juveniles developed the black markings seen in adult females of the species.

Genicanthus watanabei, also known as Watanabe’s Lyretail Angelfish or the Blackedged Angelfish, is a sought-after reef aquarium species. Its distribution is widespread in the Central and Western Pacific, but it is known as a difficult species to capture and ship in healthy condition and usually commands high prices. Captive-bred specimens would likely be in great demand among enthusiastic reef aquarists.