Fish Fauna of Johnston Is. — GOSLINE 
Dorsal rays 32 in one specimen. 
OSTRACIONTIDAE 
*Kentrocarpus hexagonus (Thunberg) 
Halstead and Bunker, 1954, 1 spec. 
*Ostracion cubicus Linnaeus 
Halstead and Bunker, 1954, 1 spec. 
Ostracion lentiginosum Schneider 
15 specs., 76-126 mm., 1951. Fowler and 
Ball, 1925, 3 specs. As Ostracion punctatum, 
Smith and Swain, 1882, 1 spec. 
*Ostracion meleagris Shaw 
Halstead and Bunker, 1954, 9 specs. 
Ostracion solorensis Bleeker 
Fowler and Ball, 1925, 1 spec. 
This specimen has the upper sides with 
alternating brown and white stripes, the 
brown ones continuous but the white ones 
broken up into segments. Below the banded 
area the body is abruptly light. A very slight 
dorsal ridge just ahead of dorsal fin; ventro- 
lateral ridges expanded into laminae. Cara- 
pace closed over behind the dorsal and anal 
fins to form two horizontal laminae. Supra- 
orbital ridges somewhat raised and rough. No 
spines anywhere. 
TETRAODONTIDAE 
Arothron meleagris (Lacepede) 
2 specs., 140 and 160 mm., 1951. Halstead 
and Bunker, 1954, 1 spec. As Tetraodon melea- 
gris, Smith and Swain, 1882, 3 specs., Fowler 
and Ball, 1925, 4 specs. 
Head, body, and fins with small light spots 
cm a dark ground. Outer portions of fins, 
except caudal, light. 
CANTHIGASTERIDAE 
Canthigaster jactator (Jenkins) 
3 specs., 40-64 mm., 1951 ; 1 spec., 52 mm., 
Brock, 1948. Halstead and Bunker, 1954, 
1 spec. 
Round white spots on a dark ground. 
463 
DIODONTIDAE 
*Diodon hystrix Linnaeus 
Smith and Swain, 1882, 1 spec. 
SECTION 2. THE NATURE AND RELATIONSHIPS 
OF THE JOHNSTON ISLAND FISH FAUNA 
Johnston Island is one of the more isolated 
of Pacific atolls. It is separated by some 450 
miles of deep water from the nearest reef area, 
French Frigate Shoals in the Hawaiian chain 
to the north (see Fig. 1). To the south and 
east the nearest shoal water (Kingman Reef 
in the Line Islands) is about 700 miles away, 
whereas the closest land to the west is in the 
Marshalls perhaps 1300 miles distant. 
The position of Johnston Island poses two 
principal questions for the zoogeographer: 
(1) to what extent does its isolation give rise 
to endemism, and (2) to what extent has 
Johnston acted as a stepping stone or filter 
bridge between the Hawaiian biota and that 
of the Line Islands to the south. An attempt 
to answer these two questions constitutes the 
present section of this paper. 
Before proceeding it seems well to define 
certain terms that will be used here. "Central 
Pacific" will be employed in a zoogeographic 
sense to refer to a faunal area whose limits 
are unknown but which includes the Line, 
Phoenix, Gilbert, and Marshall islands but 
not Johnston and the Hawaiian chain. "Ha- 
waiian" used zoogeographically will refer to 
the inshore marine fauna of the Hawaiian 
chain together with that of Johnston. "Ha- 
waii" used geographically generally refers to 
the Hawaiian chain of islands, though the 
fact that the largest island in this chain is also 
called Hawaii is admittedly confusing. 
The question of endemism amongjohnston 
fishes is easily dealt with and dismissed. Only 
two species of Johnston fishes have not been 
taken elsewhere — Centropyge nigriocellus and C. 
flammeus. Neither of these is abundant at 
Johnston (the former is known only from one 
specimen), and it may well be that they merely 
