The Hawaiian Tun Shells 
Spencer Tinker 1 
INTRODUCTION 
This article is a brief presentation of infor- 
mation on the Hawaiian tun shell fauna ( Dolii- 
dae), including synoptic keys, descriptions and 
illustrations of the different species, and notes 
on their ecology and distribution. 
Included in this paper are two species which 
the author believes to be previously unknown 
from the Hawaiian Islands. These species are 
the spotted tun shell, Tonna dolium Linnaeus, 
and the oil jar or channeled tun shell, Tonna 
canaliculata Linnaeus. No prior records of the 
occurrence of these species in Hawaiian waters 
are known. None of the local private collec- 
tions seen or the several collections in the 
Bernice P. Bishop Museum and in the United 
States National Museum included any speci- 
mens from Hawaiian waters. It is somewhat 
astonishing that two species of mollusks of this 
size should not be represented in any of these 
Hawaiian collections, some of which are very 
large and quite complete. 
The Doliidae, or tun shells, as the group is 
often called, is a small group, old and well 
established, and its members are quite easily 
recognized by the characters which they present. 
Of these characters the most significant are the 
large, light, ventricose shells with spiral ribs 
and furrows. In distribution the Doliidae is an 
Indo-Pacific group and all of its species, with 
the exception of Tonna perdix Linnaeus, are 
found within that area. 
THE HAWAIIAN DOLIID FAUNA 
Species: The Hawaiian doliid fauna is a 
small one consisting of but five species which 
represent about one-fourth of those now known. 
Of these five species, four are Indo-Pacific in 
their distribution and one, Tonna perdix Lin- 
1 Director of the Aquarium, University of Hawaii. 
Manuscript received December 6, 1948. 
naeus, is circumtropical. The following species 
are known from the Hawaiian Islands: 
Tonna perdix Linnaeus, the partridge tun 
Tonna melano stoma Jay, the black-lipped tun 
Tonna dolium Linnaeus, the spotted tun 
Tonna canaliculata Linnaeus, the channeled 
tun, and 
Malea pomum Linnaeus, the apple tun. 
Ecology: Although the Hawaiian Islands bor- 
der the Indo-Pacific faunal area and draw the 
major portion of their shore line fauna from 
this region, the Indo-Pacific species are not 
as well represented in Hawaiian waters as 
in the more centrally located areas of the region. 
This apparent dearth of species is probably due 
to the facts that the Hawaiian Islands lie on the 
extreme northern edge of this region, have a 
somewhat different ecological picture, and that 
the shore lines of the Hawaiian Islands have 
not been adequately explored beyond the depths 
comfortable for ordinary diving. In Hawaiian 
waters, at least, the members of this family 
appear to be uncommon in depths of less than 
40 or 50 feet, although occasional specimens 
of T. perdix L. are found in depths of less than 
10 feet. At depths beyond 75 feet the number 
of individuals of T. perdix L., T. dolium L., and 
Malea pomum L. increases considerably and it 
is beyond this depth that the two additional new 
records have been obtained. 
Not only does the Hawaiian doliid fauna 
become more abundant with increasing depth, 
but it is not uniformly distributed along the 
shore line: it appears to be more abundant in 
particular areas. One such area where both 
species and specimens are especially abundant 
exists along the southwestern shore of Oahu, 
and it is from this locality that the two new 
records were obtained. The reason for the 
abundance of these species in certain areas is 
unknown, but it should be noted that the area 
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