The Japanese mantis shrimp (Oratosquilla oratoria) has been detected for the first time in the Bay of Plenty region.

A single shrimp was captured in a trap near Ōmokoroa that is part of Toi Moana Bay of Plenty Regional Council’s Asian paddle crab trapping programme, being carried out in Tauranga Harbour by Manaaki Te Awanui.

The species was first reported in New Zealand in Kaipara Harbour, Northland, in 2010. The closest known location to the Bay of Plenty where they have been identified is Thames Harbour.

It is not known how the shrimp came to be in the Tauranga Harbour, but it may have migrated by natural spread.

“Bay of Plenty Regional Council marine biosecurity staff have formally identified the species,” a council spokesperson said. “Initial investigations are under way, and staff will be assessing next steps for a response plan over the coming days.

“If you think you have seen this pest, please contact the Bay of Plenty Regional Council on marine.pests@boprc.govt.nz.”

The council is asking the community to help prevent the spread of marine pests by doing the following:

Japanese mantis shrimp. Photo / Dr S. Ahyong

What does it look like?

Japanese mantis shrimps are light grey and can grow up to 18.5cm long. They have two spiny claws used to capture food.

These shrimps can easily be confused with a native species of similar size and colour. However, the Japanese shrimp has thin red-maroon lines running down the length of its body and the outer surface of the tail fan is blue and yellow (it is grey and yellow in the native species) as opposed to the thicker red-maroon midline found on the native mantis shrimp (Heterosquilla tricarinata).

Japanese mantis shrimps live in burrows in soft sediments, sand and mud in sheltered bays and estuaries. They are native to the northwestern Pacific where they are most common in the temperate waters of China and Japan.

Environmental impacts

The Japanese mantis shrimp preys on shrimps, crabs and thin-shelled molluscs, and can alter habitats through its burrowing activities. When abundant, these shrimps can play a role in structuring benthic communities and may compete for food and space with other crustaceans.

- SunLive