84 The N.Z. Journal of Science and Technology. [April 
NOTES ON THE HABITS AND USES OF THE 
TOHEROA. 
* 
By Miss M. K. Mestayer, Dominion Museum, 
On the north-west coast of the North Island of New Zealand there is a 
long stretch of clean sand, fully exposed to the Pacific swell. Here is 
the chief home of the toheroa [Amphidesma ventricosum (Grray)], which 
occupies the beaches to the practical exclusion of all other molluscs. 
Some time ago I received from Mr. H. Dargaville a very interesting 
account of this mollusc, part of which will be quoted verbatim : “ The 
largest beds are found from North Kaipara Head to Maunganui Bluff, and 
from Maunganui Bluff to Ahipara.” It has recently been found that there 
is an even better-stocked bed, extending from Onganga Bay, in Ahipara 
Bay, for fifty-four miles northwards. This has been divided into two 
areas, and arrangements are being made to invite tenders for leasing them. 
There appears to be a small bed along the coast for some considerable 
distance north of Waikanae, and there are also one or two beds in the 
South Island. These may, however, contain a closely allied species, and 
a number of specimens from different South Island localities would be 
required to settle this point. 
The toheroa are rather migratory in habit, moving up or down the coast 
in accordance with the set of the currents. “ Their mode of migration 
is as follows : At one moment you will see the bare sand as the wave 
comes in, and, immediately it starts to recede, simultaneously, and in 
hundreds or thousands, according to the size of the beds, the toheroa 
emerge from the sand, end first, and go down with the receding wave, 
and, according to the set of the tide, either up or down the beach. For 
what distance they go in this way I am unable to say, but certainly they 
move about. To-day you will find a large bed in a certain spot, and a few 
days afterwards it has quite disappeared. I think, too, that most fre¬ 
quently their journeyings take place at night, as their natural enemies, 
the seagulls and other sea-birds, are always on the look-out for them for 
food.” 
They appear to remain at about the same position relative to sea-level 
on the beach all the year round—that is, from about half to extreme low 
tide, the young ones mostly living at about half-tide. As minute toheroa 
are seen “ in millions late in January and early in February,” it is probable 
that the spawning season begins about November or December. This 
would also be suggested by the fact that “ they are fatter and more tender 
in winter than summer.” Full-grown shells reach a length of slightly 
over 6 in., but it is not known how long they require to reach this size. 
The specimen here figured, from Northern Wairoa, is 5J in. long. 
Their presence in the sand is shown by a small indentation, and the 
shells are from 6 in. to 9 in. below the surface. A fork similar to those 
used for digging potatoes is the best means of getting them out. 
When a seagull can catch one out of its hole he flies up with it to a 
height of about 20 ft., and drops it on to the hard sand, thus breaking the 
shell. 
The toheroa are extensively used as food by the Maoris and white people 
living within reach of the beds. When obtained alive they are prepared 
for the table in various ways. The Maoris place them in an open flax 
basket well wrapped in leaves, put it into their steam-oven ( laangi ), and 
