Relationships among Parapercis spp, — CANTWELL 
191 
The analysis of these data indicate that Group 
VI, those species found only near the south- 
eastern tip of Australia, Tasmania, and New 
Zealand, are more closely related to those species 
found in Japanese waters (Group I), than to 
those groups in the central west Pacific and the 
Indian oceans. P, rams ay i, the only species in 
Group V and from southeastern Australia, is 
also more closely related to those forms from 
Japan than to those from the central west Pa- 
cific area. The only species endemic to the Ha- 
waiian Islands, P. schauinslandi, was found to 
have a greater affinity for those species of the 
central west Pacific and Indian oceans than for 
those found primarily in Japanese waters or in 
southeastern Australia and New Zealand. 
This close relationship between those species 
of Japanese and southeastern Australian waters 
supports the phenomenon of bipolarity. Bi- 
polarity, or amphipolarity, is defined by Ekman 
(1953: Chap. 11) as bipolar taxonomic de- 
velopment which presupposes a center of distri- 
bution in the tropics, which served as an inter- 
mediary link between amphipolar species. Sver- 
drup et al (1942:849) refer to this phenome- 
non as bipolarity of relationship, and define it 
as "a bipolar distribution in which animals of 
higher latitudes are more closely related tax- 
onomically to each other than to those of lower 
latitudes.” 
Another phenomenon of parallel develop- 
ment exhibited by the species of the genus 
Parapercis is the larger size of the colder water 
forms. The mean greatest body depths of all 
species from Australian, Indo-central Pacific, and 
Japanese waters are, respectively, 195.2, 163.2, 
and 184.9, with mean least body depths, respec- 
tively, of 95.4, 87.8, and 94.5. The longest 
individuals are also taken from Australia and 
Japan. 
DISCUSSION 
The horizontal distribution of this genus is 
characteristic of many littoral fishes and other 
littoral fauna of the tropical and subtropical 
Indo-Pacific oceans. The great expanse of water 
in the East Pacific Ocean forms a barrier against 
dispersal of many of the shore forms to the west 
coast of America, whereas temperature plays an 
TABLE 3 
Mean Differences of Reduced Values 
Between Groups of Species of the Genus 
Parapercis 
GROUP 
I 
II 
III 
IV 
V 
I 
II 
81.5 
III 
89.2 
33.6 
IV 
55.9 
65.7 
51.0 
V 
44.7 
86.7 
96.8 
61.4 
VI 
48.3 
70.7 
88.3 
51.3 
79.1 
important role in restricting warm water ani- 
mals from migration around the southern tip of 
Africa. Temperature is also the limiting factor 
in northern and southern latitudes for littoral 
animals of this large faunal area. 
The genus Parapercis ranges from southern 
Japan to the Hawaiian and Tuamotu islands, 
southwestward to New Zealand and Tasmania, 
west to Durban on the east coast of Africa, 
thence north to the Red Sea and across the In- 
dian Ocean. 
The Indo-Malayan subregion of the Indo-west 
Pacific contains 11 of the 26 species of the 
genus, filamentosa being the only one endemic 
to this area. The number of representatives de- 
creases in a westerly direction, with only 1 
species, nebulosa, found on the east coast of 
Africa as far south as Durban. The subregion 
consisting of the islands of the central Pacific 
excluding Hawaii has but 5 species, none of 
which is endemic to this subregion. P. schauin- 
slandi, 1 of 2 species found in Hawaii, has not 
been reported from any other subregion. Of the 
10 species of the subtropical Japanese waters, 4 
are endemic to this subregion: mimaseana, mu- 
ronis, sexfasciata, and aurantiaca. The Solan- 
derian province of northeast Australia contains 
5 species, while the Dampierian province in the 
northwest has 2, none of which is endemic. 
In the south the Peronian province has 6 rep- 
resentatives, of which binivirgata, haackei, all- 
porti, and ramsayi are common to no other 
subregion. P. colias and gilliesi, the only 2 
species of the genus taken from New Zealand 
waters, are also endemic to this area. 
