Lovely toadfish sabby!
The tank... couldn't find any good info about the natural habitat of these guys, so I had to improvise when it came to decorations. It needs a good fake plant or something.
I was reading
your other post in the pictures forum about your failed attempt at finding information about their habitat. Since Neovespicula depressifrons is the same to your Vespicula depressifrons in terms of location, I think I can suggest an aquascape if you wanted to go all natural.
Since these fish inhabit all fresh, brackish, and marine waters they are tolerable of many salinities. Fish that inhabits all 3 kinds of water (FW,BW,SW) tend to prefer their SG somewhere in the middle, around 1.012. Though they prefer it around 1.012, you can possibly go to something around 1.008, which will allow growth of Java fern. If you lowered the SG to around 1.008 you can achieve the aquascape below.
Vespicula depressifrons inhabits waters around the Philippines and New Guinea. All brackish habitats are pretty much the same in terms of the natural "aquascape" (I use that word lightly). Something like this would be pretty accurate in terms of the natural habitat that a Vespicula depressifrons might live in (or as accurate as one can replicate in aquaria):
Substrate- A large layer of silver sand with a good amount of dark pea gravel sprinkled on top.
Rocks- A few large-ish rounded gray-ish rocks and a few rounded small to medium gray-ish rocks.
Flora- Java fern is the only plant that would survive in an SG around 1.010. Lots of Java fern will replicate a very natural aquascape as it will have brown around the edges at this SG and not look so artificially perfect, like many of our plants dosed with ferts and supplied with ample c02.
Wood- Curio wood wouldn’t exactly be most common wood in this particular habitat (more like bogwood and possibly driftwood) but would make an awesome aquascape. A few beautiful pieces of curio wood would be great.
Water Chemistry- With the SG in the area of 1.008 you can do the java fern, if your tank is well buffered you can use peat/black water extract which is quite common in naturally brackish waters and I think looks great in brackish tanks, and your rocks and other decor will have some algae growth on them, also very natural and realistic looking.
Hope this gives you a good mental image of what I am trying to descripe. I know, I think too much about aquascaping!