Misidentity, misinformation and misnomers are rampant and rife within the aquarium hobby and our peers. Some can be detrimental, while some are harmless pet peeves that run its course amongst new enthusiasts. We aren’t perfect, and more often than not we make mistakes. What’s important is we learn from it and spread the word of truth. Today’s midweek misnomer aims to correct a rather confusing but relatively harmless misinformation on the sexes of Pseudochromis tonozukai.
Many of us know that many species of dotty backs are sexually dichromatic, which means that males and females are coloured differently. Most of the time the males are more colourful, often sporting metallic scale patches and other gaudily coloured patterns, while females are drab and nondescript. Perhaps this stereotype has led to the confusion for at least one member in the Pseudochromis genus, and that unfortunate species is P. tonozukai.
P. tonozukai was described within the last decade (well almost) in 2004, and was named in honour of Takamasa Tonozuka. The species is medium in size with a rhomboidal caudal fin. The sexual dichromatism of this species is rather unusual, in that the males are less colourful than the females.
Both sexes have a steely grey ground colour suffused in yellow posteriodorsally. In the males, a horizontal inky black band with a constellation of blue scales run horizontally from the base of the pectoral fins and tapering off into the central rays of the diamond shaped caudal fin. There is a white band at the intersection of the body coloration and this black stripe.
The females are patterned in exactly the same way, but instead of having the horizontal band coloured in black, it is replaced instead by a bright orange. The more colourful female here is probably the source of confusion for the mix up in the sexes, and various literature online have provided confusing misinformation based on this.
P. tonozukai is not rare, but it cannot be considered common in the trade. It is a fairly large and belligerent species, and the males are especially bellicose. We had a diary entry regarding the removal of this species from our own reefs, in a manner most unorthodox. Again, as beautiful as they are, do consider the insidious nature of these fish if you’re intending to house one in a small reef tank.
Midweek Misnomers is yet another running series we hope to maintain, along with Reef Nuggets and Awesome Fish Spotlight. If you have anything you would like addressed, or see featured in any one of these running series, feel free to leave us a comment or drop us a message! We’d love to hear from you. Today’s idea for the topic on this dotty back sex confusion came from Tim Morrissey, coral aquarist at the Omaha Henry Doorly Zoo aquarium.