Fishtronics are a series of animated toy fish sold by Teamforce Co., Ltd. They require 2 AAA batteries. According to the website, they come with batteries, but I don't know if they're in the toy or packaged separately.
These fish come in four variations:
Each fish comes with a small, brown fishing rod. Photos of the shark version below came from this Mercari Japan listing.
You should play with this toy by placing it in a container of water, big enough for the fish to swim around in.
When the toy isn't functioning, it remains floating at the surface of the water. Knocking the container the fish is in, will activate its vibration sensor, telling to swim beneath the surface of the water. The toy with flap its tail as it swims in the tank, occasionally rising upwards as it swims.
You can play a game where you catch the fish using the fishing rod. When you pull it out of the water, the fish's tail will shake rapidly.
Ok, you can skip this part if you want to. I'm including info based on this toy since Teamforce promoted this toy on their homepage along with the Fishtronics toys, even though this toy isn't a part of the Fishtronics line. Plus, this toy severely lacks documentation, like the Fishtronics toys.
MARS (Marine Aquatic Rover & Submarine) is an RC toy submarine. The toy requires 3 AA batteries, while the remote contains 3 AAA batteries.
The toy is only known to come in one color scheme. Nearly half the toy ontop is mostly red, while the other half is silver. The submarine has a black window, a red propeller on its right and its left, and it has a red stripe that goes around the body of the vehicle. The color of the stripe changes to silver as it covers the part where the submarine's propellers jut out and the part that contains the propellers, since those parts are red. The submarine has what appears to be a red telescope or light stuck to the top of itself, and a long, gray antenna so the submarine can be controlled with the remote.
According to Teamforce's website, the submarine and rover parts of the toy can be separated, and "It can play like a 4 wheels driving Rover off road, climbing to the 30 degree slope hill". Yes, that's what it actually says, and I'm a bit confused.