On a “Black Friday” visit to Old Town Aquarium (so as to avoid having to shop with family on Michigan Ave…), I scoured over the tanks for something interesting and, not seeing anything that I had to have in the saltwater department, ended up purchasing a grip of neon tetra and a few plants for my freshwater tank that I’m also repopulating post-move. While the guy was bagging up the neons, I perused the saltwater aisle once more.
The Clarion was still there, gorgeous as ever, and across the row, the tail of a pipefish was spotted hanging out of the mouth of a bubble coral. I then became entranced by a yellow Rhinopias and sat contemplating the sheer weirdness of Mother Nature. As the employee approached to ask if I needed anything else, I caught a fleeting red glimpse out of my peripheral. I assumed the half crouch middle row tank viewing stance and saw a fish I’ve been coveting since I first noticed it appearing on Live Aquaria a year or so ago – Plectranthias inermis.
The Geometric Pygmy Hawkfish isn’t really a hawkfish. In the subfamily Anthiinae, it is more closely related to anthias. It does have the gorgeous blotchy pattern and many of the desirable traits of a hawkfish, but few of the bad ones – due to its small size, it is doubtful that you’ll lose many inverts, though I might be weary of putting this little perchlet in a tank with sexy shrimp.
Akin to the hawkfish, it seems to enjoy just hanging out on its gigantic (used very relatively here) pectoral fins. When the lights are on, it prefers to sit beneath rock ledges, though with just ambient daylight, it can be seen perching on the tops of corals and moving around the entire live rock structure. This makes sense, given that this fish prefers deeper waters (14 – 65m according to fishbase.org).
I haven’t seen it eat yet, though over the past 2 weeks it has become much less shy and appears to be nice and plump. I am feeding the tank a mix of PE mysis, Rod’s Food & cyclops and it is the only fish in the tank right now. My percula clowns and spotted mandarin are still in a temporary 20 long, so I can only assume it is finding something to eat.
This small fish, in my opinion, is an absolute gem for nano reef aquaria. I am happy to have found one locally and hope it does well! Here are some photos of my new basslet, to be followed by some links to other good info on Plectranthias I came across.
Geometric Pygmy Hawkfish of Nattarbox
Unarmed Perchlet on Gobies to Grizzlies








jeffry r. johnston
1 year ago
Terrific photos. We have one in the office tank. We didn’t observe it eating in the beginning, either. In fact, didn’t really see it at all. It’s gotten more confident over time and I look forward to seeing it M-F.
stonyreef
1 year ago
Hey Jeffry, thanks. They’re awesome fish, aren’t they? You should post some info and photos of your Marine Depot office tank, livestock & equipment?
Mine has gotten much more confident as well. So much so that when it sees someone walk by the tank, it usually comes out and waits for food. It likes bigger pieces – some mysis and the larger chunks out of Rod’s Food. Haven’t seen it take flakes or pellets yet, nor does it have any interest in cyclops.
jeffry r. johnston
1 year ago
Our office tank isn’t too impressive since we changed buildings. Plans once were to put an enormous tank on the first floor that you can look through into a conference room. Of course, then the economy took a turn so not sure if that will be happening anytime soon (although the plumbing seems to be in place). We just have a small JBJ nano upstairs we use for filming videos. As far as livestock goes we’ve got various snails (Cerith, Nassarius, Turbo) and hermits (red, blue), 2 peppermint shrimp, 1 Pygmy Hawk, 1 Yellow Watchman and various frags from employees. We had a McCosker Wrasse but he didn’t make it. As the tank evolves we’ll probably give a little more coverage but mostly it’s for shooting how-to videos and testing new stuff (purchasing is always throwing new lighting fixtures and bulbs on there).