Observations on a Specimen of Bluefin Tuna (Thunnus thynnus) 
Taken in Hawaiian Waters 
Fred C. June^ 
The bluefin tuna, Thunnus thynnus (Linne), 
has been reported from Hawaiian waters by 
several authors (Fowler, 1923 and 1928; 
Jordan and Evermann, 1926), however, it ap- 
pears only rarely in the commercial tuna 
catches from this area. The last confirmed re- 
port of the occurrence of this species was a 
landing made by a commercial long-line boat 
off the coast of Waianae, Oahu, in 1939. 
There have been reports of bluefin tuna being 
taken along the Kona coast of the island of 
Hawaii, but they have been infrequent and 
the identifications were not validated. 
On October 3, 1950, a specimen weighing 
223 pounds was captured on long-line gear 
by the vessel llima while fishing off the south- 
west coast of Oahu, at approximately 21° 
26' N., 158° 27' W. and at an estimated depth 
of 60 fathoms. 
Measurements on this specimen were taken 
on October 6, 1950, at the Kyodo Fishing 
Co., Ltd., Honolulu, where the fish catch of 
the llima was unloaded for disposition. Vis- 
cera, for subsequent laboratory examination, 
were also obtained at this time. The various 
measurements, according to the methods de- 
scribed by Marr and Schaefer (1949), and 
meristic counts are given in Table 1 for the 
benefit of those interested in a critical study 
of the morphometric characters and distribu- 
tion of this fish. 
In all anatomical characters examined, this 
specimen agreed with Godsil and Holmberg’s 
(1950) detailed description of the Pacific 
1 Pacific Oceanic Fishery Investigations, Honolulu, 
Hawaii. Manuscript received May 11, 1951. 
bluefin tuna, Thunnus thynnus. It also showed 
remarkable agreement with Kishinouye’s 
(1923) description of Thunnus orientalis., ex- 
cept for the author’s notation regarding the 
division of the ureter as it enters the kidney. 
Kishinouye (1923: 309) states, 'dn Thunnus 
orientalis the two ureters meet in a figure like 
U, and in other forms of the Japanese tunnies 
they meet like the figure V.” In the Hawaiian 
specimen, the ureters met in a figure V at a 
point 31 mm. within the posterior margin of 
the kidney. The left branch continued anter- 
iorly for a short distance, then diverged sharp- 
ly, whereas the right branch curved outward 
gradually from the point of division. Both 
observations follow Godsil and Holmberg’s 
findings for T. thynnus. 
Another point of apparent difference be- 
tween the description given by Godsil and 
Holmberg and that of Kishinouye concerns 
the branching of the coeliac-mesenteric ar- 
tery. Kishinouye (1923: 378) indicates the 
presence of an abortive No. 1 branch in T. 
orientalis. He states, "In [the genus Thunnus] 
the first branch is abortive and nourishes the 
oesophagus only, or is entirely absent.” God- 
sil and Holmberg (1950: 42) found no No. 1 
branch in T. thynnus and conclude, "Occa- 
sionally a capillary-size vessel is present, 
originating approximately where the No. 1 
branch should be, and like it running to the 
oesophagus. This vessel is so small, and is 
moreover one of several originating in this 
region and nourishing the adjacent tissues, 
that it was not considered homologous with 
No. 1 branch.” There was no evidence of a 
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