News / Species Spotlight / Dr. Seuss Fish (Belonoperca pylei) (09/19/18)

Dr. Seuss Fish (Belonoperca pylei)

Species Spotlight - Dr. Seuss Fish (Belonoperca pylei)
The evocatively named Dr Seuss Soapfish is definitely high in the rankings when it comes to strange reef fishes. The body is long and angular, with a disproportionately large head, and along the sides are giraffe-like spots in a bright shade of red to match with the orange of the head. One might think that such ostentatious markings would result in this fish being easily spotted by predators, but, at the depths where this creature occurs, red light is virtually absent, allowing it to blend in against the gloomy reef.

Belonoperca is one of the most distinctive members of the soapfish tribe, itself a subgroup of the large grouper family Serranidae. The soapfishes are well-known for the sudsy defensive chemical exuded by the skin, and this small genus is no exception. Laboratory tests have shown that Belonoperca do contain grammistins, but it seems they are less inclined or less able to secrete them in a manner that can cause harm to an aquarium.

The Arrowhead Soapfish (B. chaubandi) is by far the most frequently seen example, though it is by no means a common aquarium inhabitant. But considerably rarer is the only other species in this genus of slender-bodied soapfishes, B. pylei. The first specimens were discovered in 1989 at great depth (85-120 meters) in the Cook Islands of the South Pacific by the famed mesophotic ichthyologist Dr. Richard Pyle and a local fish exporter, Chip Boyle (of Peppermint Angelfish fame).

In the years since this initial sighting, additional specimens have been found at a similar depth range in the Marshall Islands and Pohnpei, Micronesia, indicating that the species is likely to be widespread throughout much of the Central Pacific (though it is clearly absent from Hawaii).

In captivity, specimens are quick to acclimate, though the species is naturally secretive and prone to lurking among the nooks and crannies of the reef. As it is essentially a miniature grouper, the diet consists of an indiscriminate mix of small fishes and shrimps. To reiterate an earlier point, the mouth is surprisingly capacious in this animal, so dont underestimate its ability to snack upon smaller tankmates. Anything less than half its size can easily fall prey to this bizarre Suessian predator.

A dimly lit mesophotic biotope would make for the ideal situation to house B. pylei, along with others from this twilight realm, like the aforementioned Peppermint Angelfish (Paracentropyge boylei), the Blotchy Anthias (Odontanthias borbonius), and perhaps a Magma Wrasse (Cirrhilabrus shutmani). Few will ever get a chance to see these fishes in the wild, but its certainly possible to recreate this unique ecosystem at home... though not cheaply.