The company, which develops technology to ward off predators from salmon farms, floated around 30.5mln shares at a placing price of 57.5p, giving it a market cap of £17.6mln.
The firm raised an additional £1.5mln through an equity placing in parallel to the reverse takeover.
OTAQ also develops products including sub-sea cameras, laser measuring devices, leak detection systems and high integrity electrical connectors for use in the offshore oil & gas market.
The company currently holds a 42% market share of predator-defence technology in Scotland and is expected to see equivalent market share growth in Chile, the world's second-largest salmon farming country.
In lunchtime trading on Tuesday, shares in OTAQ were at 54p, a 6% discount to its placing price.