Ibacus alticrenatus is one of the smaller species of Ibacus. Males reach a maximum carapace length of 55 millimetres (2.2 in), with females slightly larger, at up to 65 mm (2.6 in). The maximum total length is 16 centimetres (6.3 in). There are typically 8, but occasionally 7 or 9, teeth along either edge of the carapace.

Usually found in soft sediments at depths around 200m or more.

Not well understood but likely either a predator or scavenger.

The highest total landing in New Zealand for any fishing season was 49.12 t in 1992–1993. I. alticrenatus was added to New Zealand's Quota Management System on October 1, 2007, and the total allowable catch was set to 37.4 t.The majority of the catch is taken in the area to the north of North Island. Because of its wide range, Ibacus alticrenatus is listed as Least Concern on the IUCN Red List.

M. Butler, A. Cockcroft & A. MacDiarmid (2011). "Ibacus alticrenatus". IUCN Red List of Threatened Species. Version 2012.2. International Union for Conservation of Nature. "Proposal to list prawn killer (PRK) on the sixth schedule of the Fisheries Act 1996 – final advice" (PDF). Ministry for Primary Industries.