Acanthophora in Hawaii — Doty 
549 
could have arrived in Hawaii from the west on 
a ship bottom, i.e., a man-made facilitation of 
the oceanic drift method of dispersal. This 
would be the carrying of an organism "up- 
stream.” 8 The progressive increase in abun- 
dance around the island over several years’ time, 
and, recently, what appears to be a leveling off 
in abundance, is considered evidence of an in- 
troduction into the Honolulu-Pearl Harbor 
area. The Honolulu-Pearl Harbor shore area is 
the part of the state having the greatest traffic 
with regions of the world where Acanthophora 
has been known as a common component of the 
flora for a long time. This area is not climatically 
extreme for the state. However, since Honolulu 
has been in contact with the East and West via 
ship for centuries, it seems likely that some re- 
cent unusual occurrence may have implemented 
this transport. The three following events have 
come to our attention and are considered in 
this regard. 
First, the recent warming of North Pacific 
waters (e.g., since the low temperature year of 
1955 at Christmas Island, 2° N., 157° W.) 
would not, it seems, be accountable for the fol- 
lowing reasons: first, the warm temperatures 
did not begin until after the alga was well 
known in Hawaii, and, secondly, there has been 
little abnormality of water temperatures in the 
Hawaiian area itself. 
A second unsual event that may have led to 
the introduction is the increase in traffic be- 
tween the Honolulu-Pearl Harbor area and the 
Far East during World War II, 1941-45, and 
during the Korean Police Action, 1950-53. The 
idea is that a number of small introductions at 
nearly the same time might have provided to- 
gether a sufficiently large inoculation for the 
species to become established. From the rate of 
spread we tend to exclude the first period. The 
second is more timely. There is no special evi- 
dence that would lead one to choose this latter 
as the probable period, though such changes in 
oceanic traffic have been held to account for 
8 This is the customarily postulated direction of mi- 
gration in deriving the populations of Hawaii, as sum- 
marized by Zimmerman (1948), and Gosline and 
Brock (I960). Ladd (I960) has emphasized a some- 
what different possible mode of origin for the popu- 
lations of the Pacific islands. 
the distribution of barnacles in some cases else- 
where in the world. 
A heavily fouled barge, the "Yon 146,” towed 
to Pearl Harbor from Guam, provides an exam- 
ple of the third, and more specific, type of event 
that may have led to the establishment of Acan- 
thophora in Hawaii. The idea here is that one 
heavily "fouled bottom” could have provided a 
sufficiently large inoculation for the species to 
become established. Upon arriving in Pearl Har- 
bor February 3, 1950, this "fuel oil barge (non- 
self-propelled)” was placed in a dry dock. The 
Pearl Harbor dry docks are about 12 km. by 
water and 8 km. in a straight line from the 
place Cutress collected the first material of 
Acanthophora found in Hawaii. The dry dock 
is about 30 km. by water from the place Tinker 
first found this species of Acanthophora. 
Fish and gastropod collections were made 
both from the growths, often 3-8 in. thick, on 
the barge and from the small pools left under 
the barge in the otherwise dry dry dock. They 
were made, at least in part, on April 10, 1950, 
and variously by Tinker, George Campbell, and 
Kenneth A. Wong. This vessel, 200 ft. long, 56 
ft. in beam, concrete-hulled, under different 
descriptive names, has been mentioned as a pos- 
sible means of fish introduction by several au- 
thors, e.g., by Gosline and Brock (I960: 26), 
who have studied collections made on it. The 
same vessel is reported by Edmondson (1951: 
183, 212) as having brought in invertebrates 
which have become established, 9 such as the 
brachyuran crab, Schizophrys asp ere, common to 
the far western Pacific. Chapman and Schultz 
9 From accounts of long-time residents of the area, 
known distribution of the species, and information in 
the literature, it seems to me almost certain that Coty- 
lorhizoides pacijicus (Mayer) and Cassiopea medusa 
(Light), both Rhizostomae, were accidentally intro- 
duced to the Pearl Harbor area during the 1941-45 
period. The type locality of these two medusae is the 
Philippine Islands. In Hawaii both were restricted to 
Pearl Harbor until about 1950. About this time, 
Cassiopea appeared in Honolulu Harbor and the Ala 
Wai Canal. Later, 1953-54, Cotylorhizoides appeared 
in Kaneohe Bay. Until the time of my departure (De- 
cember, 1955) neither medusa was known from the 
other Hawaiian Islands, Line Islands, Marshalls, Gil- 
berts, etc. Both forms undoubtedly came to Hawaii as 
scyphistoma on ships or the like, as neither are medu- 
sae of the open ocean. — C. E. Cutress, June, I960. 
