Fish Fauna of Johnston Is. — Gosline 
477 
TABLE 8 
Types of Markings at Pectoral Base in Phoenix and Line Island Samples of Acanthurus triostegus 
For explanation of lettering, see text 
LOCALITY 
AA 
AB 
AC 
AD 
BB 
BC 
BD 
cc 
CD 
DD 
Line Is.: Christmas 
1 
0 
1 
1 
15 
1 
4 
3 
0 
1 
Phoenix Is.: Hull 
4 
2 
0 
1 
17 
2 
3 
2 
1 
1 
TABLE 9 
Types of Markings at Pectoral Base in Phoenix and Line Island Samples of Acanthurus triostegus 
LOCALITY 
"MARSHALLESE” 
"marquesan” 
"HAWAIIAN” 
Line Is.: Christmas 
35 (65%) 
8 (15%) 
11 (20%) 
Phoenix Is.: Hull 
41 (52%) 
7 (11%) 
18 (27%) 
mens. That introgression of A. sandvicensis 
genes into these populations has occured via 
passage of Hawaiian individuals through the 
Line Islands is contra-indicated by the aver- 
age fin counts of Line Island samples. 
Res ults of the Species Analyses 
Though the nature of the available material 
precludes very extensive cross comparisons 
between species, a certain amount of integra- 
tion between the results of the various species 
can be made. 
The first point regards the nature of the 
morphological distinctions of the Hawaiian 
endemic forms. In an earlier paper (Gosline, 
In press) it was stated: "In morphological 
features the Hawaiian endemic fishes show 
no pattern of divergence from their Central 
Pacific relatives.” However, in view of Stras- 
burg’s recent paper (1955) demonstrating 
that in the Istiblennius edentulus complex there 
is a rather close correlation between fin ray 
count and water temperature, it seems well to 
reinvestigate this statement. Among the six 
species pairs dealt with here, four differ in 
coloration, three in meristic counts, one in 
the position of the dorsal origin, and one in 
the shape of the head. Of those differing in 
color, Gymnothorax eurostus is separable pri- 
marily on the basis of the mottling of the 
throat, Cirrhitus alternatus in the absence of 
brown spots on the body, Chaetodon multi - 
cinctus in the presence of more prominent 
barring on the nape and caudal peduncle, and 
Acanthurus sandvicensis in the long curved 
streak below the pectoral base. There seems 
to be no pattern of differentiation here. How- 
ever, a pattern does emerge from the meristic 
data. Of those species pairs differing in meris- 
tic characters, two of the Hawaiian endemics 
have more pectoral rays ( Kuhlia sandvicensis 
and Chaetodon midticinctus) , two have more 
dorsal and anal soft rays ( Chaetodon multi- 
cinctus and Acanthurus sandvicensis) , and one 
has fewer gill rakers ( Kuhlia sandvicensis) . Thus 
for fin rays, if not for gill rakers, there does 
seem to be a trend toward higher meristic 
counts in these Hawaiian endemics. Other 
species showing the same trend that are not 
dealt with here are Istiblennius zebra (see Stras- 
burg, op. cit.) and Dascyllus albisella. However, 
what has just been said should not obscure the 
fact that there are many species in which the 
Hawaiian form shows no increase in counts 
and at least a few in which a decrease occurs. 
Thus the Hawaiian trichonotid Crystallodytes 
cookei differs from its Phoenix Island counter- 
part only, so far as known, in having fewer 
dorsal and anal rays (Schultz, 1943: 266), and 
the Hawaiian gobioid Kraemeria bryani differs 
