Fishes Killed by the 1950 Eruption of Mauna Loa 
III. Sternoptychidae 1 
Janet Haig 2 
The extensive collection of fishes yielded 
by the Mauna Loa lava flow of 1950 included 
45 hatchetfishes (Sternoptychidae) belonging 
to four species. They are of particular interest 
in view of the fact that two of these species 
have not hitherto been reported from the 
Hawaiian Islands, nor from anywhere in the 
central Pacific region. One species known 
from the Hawaiian Islands was not included 
in the collections. 
Three of the hatchetfishes were cooked to 
the point where the flesh was falling off the 
bones, and were utterly unfit for detailed 
study, although still identifiable. A few more 
were in mediocre condition. The great ma- 
jority, however, were in an excellent state of 
preservation, even retaining some of the thin 
deciduous scales which are usually lost in 
sternoptychids collected by the more con- 
ventional methods. 
The five Hawaiian members of the family 
Sternoptychidae have all been described and 
figured elsewhere, some of them many times. 
For this reason it was considered unneccessary 
to include lengthy descriptions and detailed 
figures in this paper. Aside from original 
1 Contribution No. 155 from the Allan Hancock 
Foundation. Manuscript received August 30, 1954. 
2 Allan Hancock Foundation, University of Southern 
California, Los Angeles. 
descriptions, the synonymies include refer- 
ences to Hawaiian localities only. 
Sternoptychids are subject to great indi- 
vidual variation, the limits of which are still 
incompletely known, and data on this subject 
are useful in studies of the family. Measure- 
ments and counts for the lava flow material 
is therefore included in Table 1. 
Particulars on the Mauna Loa lava flow and 
the collections appear in the first paper of this 
series (Gosline et al ., 1954). 
The author is indebted to Dr. William A. 
Gosline for the opportunity to examine and 
report on this interesting collection, and to 
Dr. Leonard P. Schultz for supplying informa- 
tion on Polyipnus nuttingi . 
KEY TO THE HAWAIIAN STERNOPTYCHIDAE 
1. Eye normal; anal fin undivided 2 
Eye telescopic; anal fin divided; dorsal fin 
preceded by a transparent blade 3 
2. An abrupt ventral constriction between 
trunk and postabdominal region, this 
space filled by a transparent integumentary 
plate; dorsal fin preceded by a transparent 
blade Sternoptyx diaphana 
No abrupt ventral constriction between 
trunk and postabdominal region; dorsal 
fin preceded by a forked spine 
Polyipnus nuttingi 
318 
