A New Hawaiian Engraulid Fish 
Donald W. Strasburg 1 
The oceanic skipjack or aku ( Katsuwonus 
pelamis ) is commercially the most important 
fish in the Hawaiian Islands. This tuna is cap- 
tured by pole and line, using live bait as chum. 
Of the several species of small fish employed 
as bait, the endemic anchovy known as nehu 
(Stolephorus purpureus, family Engraulidae) 
forms the major skipjack bait resource. Its im- 
portance in this respect has made the nehu the 
subject of several studies, resulting in reports 
on its food habits (Hiatt, 1951), spawning 
(Tester, 1951, 1955), oxygen requirements 
(Pritchard, 1955), meristic variation (Tester 
and Hiatt, 1952), and taxonomy (Gosline, 
1951). Biologically, the nehu is probably the 
best-known fish in the Hawaiian Islands. 
The nehu is a carnivorous anchovy, living and 
breeding in estuaries and bays. It is captured by 
seine during the day, and by a combination of 
seine and electric light at night. The nehu has 
been regarded as neritic except for two puzzling 
circumstances: the nehu population in Maalaea 
Bay, Maui, is periodically augmented by incur- 
sions of fish apparently from the open sea, and 
eggs differing only slightly from those of nehu 
were once taken in the offshore waters of Oahu 
(Tester, personal communication ) . 
During the summer of 1958 the research 
vessel "Charles H. Gilbert” of the U. S. Fish 
and Wildlife Service encountered several large 
schools of anchovies 5-30 mi. off Oahu. Samples 
were presumed to be nehu and were not pre- 
served. Later, conversation with commercial 
fishermen revealed that, while not regularly oc- 
curring, such schools were not rare, and also that 
the fish differed from nehu in both color and 
shape. Some fishermen termed these fish "oki- 
iwashi,” which is literally translated as "pelagic 
sardine-like fish,” while others referred to them 
as "roundheads.” The latter name was descrip- 
1 U. S. Fish and Wildlife Service, Honolulu, Hawaii. 
Manuscript received February 4, 1959. 
tive of the short head which caused the fish to 
be gilled in seines used for nehu. 
Thinking that this offshore anchovy repre- 
sented either a different species or an ecological 
variant of nehu, we intensified our efforts to 
obtain specimens from areas removed from the 
inshore nehu grounds. Ultimately, two small col- 
lections were obtained, one through the interest 
of Captain Noboru Tsue of the M/Y "Buc- 
caneer,” the other from biologists of the Terri- 
torial Division of Fish and Game (Honolulu). 
Examination of these specimens proved them to 
be not only distinct from nehu but also new 
to science. It is the purpose of this paper to 
describe and distinguish this new Hawaiian 
anchovy. 
In addition to the collectors, thanks are due 
also to Drs. Albert L. Tester and William A. 
Gosline of the University of Hawaii, the former 
for making available meristic data for nehu, the 
latter for examining specimens of Anchoviella 
mauli. I am also grateful to Mr. John G. Simp- 
son of the Inter-American Tropical Tuna Com- 
mission for data on Central American Ancho- 
viella. 
METHODS 
All meristic data were enumerated from spec- 
imens stained with alizarin. Articulated and 
nonarticulated fin rays were not differentiated, 
and those rays split to a single base were counted 
as single rays. All gill rakers, including rudi- 
ments, were counted from the first arch on the 
right side. Distinction between the upper and 
lower limbs of gill arches was made on the 
presence of 1-3 rakers with bases embedded in 
connective tissue between the two portions of 
the arch. Because most specimens had lost their 
scales, the number of scale rows was obtained 
by counting the scale pockets. The only meas- 
urement needing description is maxillary length, 
which was taken as a straight line between the 
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