Introduction
Elephant fish (Callorhinchus milii) are named for their distinctive lobed, trunk-like snout, but although named for it, its use is still highly debated. Theories suggest the detection of food in the sea floor sediment, or to dig prey items out of the sandy or muddy seafloor.

Population distribution and habitat
There are three different elephant fish in the world's oceans. Australia has the same elephant fish that is found in New Zealand waters, but it doesn't grow as big. Both South Africa and South America have similar looking but slightly different species. In New Zealand elephant fish are uncommon around the north of the North Island, occurring only south of East Cape on the east coast and south of Kaipara on the west.
Adult elephant fish spend most of the year in water deeper than 100 m, but during spring and summer migrate into shallow water to lay their eggs.

Spawning and breeding behaviour
Mature elephant fish migrate to shallow inshore waters in spring and summer where they lay 2 eggs simultaneously, each protected by a hard keratinous egg case. Egg cases average about 24 cm long by 10 cm wide and are a golden yellow colour on laying, which slowly changes through a brown to black when it nears hatching. Egg cases are laid on sand or mud bottoms, in water as shallow as two metres. Any bay throughout their distribution where the seafloor has a gentle gradient and soft sediment is a potential spawning site.

It takes about 7 months for the juvenile elephant fish to hatch from their egg cases, but this time will vary depending on the water temperature. The hatchlings are between 14 and 16 cm long (total length) and will slowly move from the shallow water to deeper water as they grow.

Age, size and growth
Male elephant fish mature at a length of 50 cm (fork length) which is about 3 years of age, females mature much later at 70 cm fork length which is 4 to 5 years of age. The greatest reliable lengths for New Zealand elephant fish are for males 76 cm long and 97 cm for females.

Feeding behaviour
Some studies off the Otago coast found elephant fish were eating a large numbers of molluscs, as well as some crustacea and fish. The most consistently found item in gut contents were the crushed shells of the clam Maorimactra ordinaria.

Traditional Maori fisheries
Elephant fish (reperepe or rewharewha) is a treasured Ngai Tahu food source. It is considered a good food fish and was much sought after in pre-European times. Reperepe was netted and sometimes hooked during the late summer months. The fish was cut into small strips, wind dried, then stored in poha (bull kelp bags). Ngai Tahu have identified the inshore area of Pegasus Bay as the main breeding ground, and fishing there during the spring breeding season was prohibited.

Commercial fishing
Elephant fish have been commercially fished in New Zealand since the 1800s. Today the majority of the close to 1000 tonnes caught annually is taken in the Canterbury Bight and Pegasus Bay, although fish are landed in commercial quantities from right around the South Island. It was not until the late 1950s that a market was found for these fish and they were targeted directly. This market was the fish and chip trade, you may remember buying silver trumpeter or white fillets, well that's elephant fish. Today's fishery has a large mainly non-targeted seasonal catch, mostly during spring and summer by vessels trawling for red cod or flatfish. However, direct targeting of elephant fish does continue on the Canterbury coast by a small number of small inshore vessels. Today most of the elephant fish commercially caught in New Zealand is exported for sale in Australia.

References
Ayling, T., Cox, G. J., 1984. Collins Guide to the Sea Fishes of New Zealand. William Collins Publishers, Auckland.
Best, E., 1929. Fishing methods and devices of the Maori. Dominion Museum Bulletin No.12.
Duffy, C.A.J. 2000: Elephantfish (Callorhinchus milii) spawning sites in the Marlborough Sounds, South Island, New Zealand. (unpublished report in Hurst et al. 2000: Areas of importance for spawning, pupping or egg-laying, and juveniles of New Zealand coastal fish. Final Research Report for Ministry of Fisheries Research Project ENV1999/03 Objective 1)
Francis, M.P. 1997: Spatial and temporal variation in the growth rate of elephantfish (Callorhinchus milii). New Zealand Journal of Marine and Freshwater Research 31: 9-23.
Gorman, T.B.S. 1963: Biological and economic aspects of the elephantfish, Callorhynchus milii Bory, in Pegasus Bay and the Canterbury Bight. Fisheries Technical Report No. 8. 54 p.
Graham, D.H. 1939: Food of the fishes of Otago Harbour and adjacent seas. Transactions of the Royal Society New Zealand 68: 421-436. McClatchie, S., Lester, P., 1994. Stock assessment of the elephantfish (Callorhinchus milii). N.Z. Fisheries Assessment Research Document 94/6. 17 p.
Paulin, C., Stewart, A., Roberts, C., McMillan, P., 1989. New Zealand fish: a complete guide. National Museum of New Zealand Miscellaneous Series No. 19. 279 p.
Raj, L., Voller, R., 1999. Characterisation of the south-east elephantfish fishery-1998. (Report held by Ministry of Fisheries, Dunedin, New Zealand). 55 p.
Ste aracterisation of the south-east elephantfish fishery-1998. (Report held by Ministry of Fisheries, Dunedin, New Zealand). 55 p.
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