Merck & Co. Inc.'s animal health division completed its acquisition of Vaki, a fish monitoring equipment maker, from water treatment company Pentair PLC.

Kenilworth, N.J.-based Merck did not disclose financial details of the deal.

Merck Animal Health said the acquisition expands its aquaculture portfolio to include precision farming and fish welfare solutions, which complement the company's portfolio of vaccines and pharmaceuticals.

Kópavogur, Iceland-based Vaki will be housed under Merck Animal Health's Biomark business, which specializes in electronic identification technology used in fisheries, wildlife and aquaculture research.

In April, Merck acquired animal identification company Antelliq Corp. from funds advised by London-based BC Partners for about €2.1 billion.