388 PACIFIC SCIENCE, Volume 47, October 1993
FIGURE 79. Naso brevirostris (J. Randall).
FIGURE 78. Acanthurus triostegus sandvicensis (J. Randall).

Kanenaka (1984). Not observed by us, but from the latitudinal distribution of the species (as far north as Iwate Prefecture, Japan, and as far south as New Zealand), it is expected at the atoll.

Acanthurus leucopareius (Jenkins, 1903)
BPBM 34810, 2: 33-42 mm. Abundant inshore on reefs outside the lagoon. This species
and Acanthurus triostegus often feed in dense aggregations that overwhelm the defenses of
guarding territorial damselfishes.

Acanthurus nigrofuscus (Forsskal, 1775)
One specimen collected on a lagoon reef by personnel of the Hawaii Cooperative Fishery Research Unit, along with A. nigroris. Identified by the fourth author and James E. Norris. Used for gut content analysis but not saved. None seen in 1989-1992.

Acanthurus nigroris Valenciennes, 1835
BPBM 34811, 2: 42-49 mm; BPBM 34897, 131 mm. Abundant on reefs outside the lagoon from depths of less than 2 to over 20m.

Acanthurus olivaceus (Bloch & Schneider, 1801)
Plate IVE
Occasional, mainly outside the lagoon. Listed from Midway by Okamoto and Kanenaka (1984).

Acanthurus thompsoni (Fowler, 1923)
Occasional outside the lagoon, usually at depths greater than 20 m. An underwater
photograph is on file at the Bishop Museum. Some yellow juveniles were seen at a small
dropoff in 26 m, along with others of about the same size and slightly larger that were
yellowish brown with slightly diagonal bluish longitudinal lines on the body.

Acanthurus triostegus sandvicensis Streets,
Figure 78
Abundant inshore, especially outside the lagoon. From counts made outside the wind ward reef at Midway, Hobson (1980) ranked, this surgeonfish as the most common of all the
fishes. However, the population diminishes greatly with depth, so few individuals are seen
below about 15 m.

Ctenochaetus strigosus (Bennett, 1828)
Plate IVF PBM 35389, 127 mm.
Common, particularly outside the lagoon from about 6 to 25 m.

Naso annulatus (Quoy & gaimard, 1824)
1877 Rare; two subaduIts observed at the edge of a dropoff outside the lagoon in 26 m by J.E.R. and Lisa Privitera.

Naso brevirostris (Valenciennes, 1835)
Figure 79
Occasional over reefs outside the lagoon. The adult of Figure 79 was photographed in 9m.

Naso hexacanthus (Bleeker, 1855)
Rare; only two individuals sighted outside the lagoon southeast of Sand Island, one of
which was distantly photographed (photo on file at Bishop Museum).