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PACIFIC SCIENCE, Vol. XII, October, 1958 
pursuit of the Labroides in the aquarium sug- 
gests that the wrasses might have been 
conditioned to rapid seizure of food items 
added to the surface of the tank, and that this 
reaction may have superseded the one which 
would occur in the normal habitat. 
When in the proximity of other fishes, 
Labroides phthirophagus exhibits the same un- 
usual oscillatory mode of swimming as seen 
in L. dimidiatus , although not as commonly. 
As previously mentioned, the act of re- 
moval of ectoparasites by L. phthirophagus 
frequently takes place in a region of cover 
such as beneath a ledge. Repeated observa- 
tions of one such ledge at Manana Island, 
Oahu, revealed that a pair of this species of 
Labroides could invariably be found at or near 
this site. These observations continued for a 
period of over three years. Other pairs or 
groups of three fish were similarly checked 
over long periods of time at the following 
locations: Waikiki, Kaneohe Bay, Hanauma 
Bay, and Kealakekua Bay, Hawaii. I conclude 
from these and lesser observations that adult 
L. phthirophagus tend to remain in a restricted 
area of the reef. 
As with Labroides dimidiatus , it is believed 
that fishes seek out the area where Labroides 
phthirophagus occur in order to have their 
parasites removed. The first evidence that 
fishes might come to a Labroides site from be- 
yond the immediate vicinity was the sighting 
at Manana Island of an adult manini, Acan- 
thurus triostegus sandvicensis Streets, swimming 
from at least 40 feet away direct to the 
Labroides ledge where it stopped and erected 
its fins. As one of the Labroides swam up to 
this fish, the latter was speared and taken 
ashore. Macroscopic examination revealed the 
presence of three calagoid copepods. Seem- 
ingly purposeful swimming by other fishes to 
Labroides areas has been observed. Generally 
there is a concentration of reef fishes around 
a Labroides site. I have on several occasions 
located such a site by first noting a greater 
density of reef fishes in a restricted area than 
could be explained by any other reason. 
Labroides sites are usually well separated 
from one another. This first became evident 
around the patch reefs in Kaneohe Bay. 
Labroides phthirophagus is generally found at 
a depth of about 5 to 20 feet at the steep 
margins of these reefs rather than their shal- 
low, truncate tops. The spacing between sites, 
at times remarkably regular, is now linear and 
more readily perceived by an observer swim- 
ming around such a reef. 
Although occurring singly or in groups of 
as many as five individuals, Labroides phthiro- 
phagus is most commonly seen in pairs. Often 
groups of three or more contain one or more 
juveniles in the company of a pair of adults. 
When a pair of adults is seen, it is natural to 
expect that one would be a male and the 
other a female. There is some evidence that 
this is the case. Of the four specimens shown 
in Table 1 which were collected at a poison 
station on December 31, 1952, two are males 
and two are females. One of the two para- 
types which were speared on October 14, 
1955, at Waianae, Oahu, is a ripe female 
(standard length 64 mm.; length of ovary in 
situ 12 mm.) and the other appears to be a 
male. These two fishes were found together 
and were the only two seen in the area 
surveyed. 
Labroides rubrolabiatus , new species 
PI. 1 R 
holotype: U. S. Natl. Mus. No. 164603, 
a female specimen, 54 mm. in standard length 
and 66.5 mm. in total length, collected by 
J. Randall with rotenone in the lagoon at a 
depth of 20 feet next to a large coral head 
about 100 feet from shore one-fourth of a 
mile east of the entrance to Papetoai Bay, 
Moorea, Society Islands, on May 3, 1956. 
paratypes: U. S. Natl. Mus. No. 164604, 
a female specimen, 51 mm. in standard length, 
collected by J. Randall with a spear 30 feet off 
the lee reef near the boat entrance of Caroline 
Atoll (10° S. 150° 14' W.) at a depth of about 
15 feet on February 12, 1956; Stanford Univ. 
