RVS Fishworld INC has shown off a male angelfish that appears to be a hybrid between the Japanese swallowtail angelfish, Genicanthus melanospilos, and the Mask swallowtail angelfish, Genicanthus semifasciatus. Keen to know more, we spoke to Barnett Shutmann at RVS, who replied directly from his base in the Philippines:
“The net caught and PADI scuba training in Calayan island conducted by RVS Fishworld INC in cooperation with Mayor Llopis and his local government unit and the Bureau of Fisheries and Aquatic Resources in the Philippines has been bountiful as a previous Reef Builders article not too long ago by Reefbuilders highlights.
This fish however deserves its very own article. It is what appears to be a hybrid between the Japanese swallowtail angelfish, Genicanthus melanospilos and the Mask swallowtail angelfish, Genicanthus semifasciatus.
At a quick glance, it would appear to look like a developing aberrant male specimen of melanospilos but as is sometimes the case there are some subtle differences that suggest otherwise. The yellow that remains in the top half of the body, although subtle, seems to run deeper towards the lateral line as in juvenile and female semifasciatus. The pattern in the developing striping also matches closely. The edges of the dorsal and anal fins also seem to have hints of semifasciatus also.
This fish was caught at 50m depth just off Calayan Island by one of the trained divers who are all consistently proving that the collection of aquarium fish when done correctly and sustainably is of real benefit to the coastal communities of our tropical seas.
These two similar species do overlap in range from the northern Philippines right up to Japan so a hybrid was probably an inevitable find at some point, however, this appears to be the first. Hopefully, RVS Fishworld INC can find more (and perhaps other life stages) of this hybrid. We also hope to get a chance to watch this specimen develop into full adulthood.”