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PACIFIC SCIENCE, Vol. XII, October, 1958 
tions. Furthermore he observed that the 
larger fish seek out the stations of the "clean- 
ers.” He made the following observation of 
Elacatinus oceanops and Epinephelus striatus. As 
soon as the grouper came close to the coral 
where the gobies were located, the little fish 
swam immediately in his direction and started 
to clean his body. Sometimes the grouper lay 
on his side. He allowed the gobies to enter 
and leave the buccal cavity through his mouth 
and gill openings which he held rigidly open. 
After about 30 seconds he respired once or 
twice and then opened his mouth and elevated 
his gill covers again. When he wanted to 
leave, he made a signal by closing his mouth 
sharply, although not completely, and then 
opening it widely. At this signal the gobies 
came out. Before leaving the grouper shook 
his body. Even if frightened (as by a diver) he 
still took time to make the signal to the 
gobies. Of the small fishes listed above which 
cleanse larger fishes, only Elacatinus oceanops 
and young Bodianus rufus were seen to enter 
the buccal cavity of larger fishes. Large fish 
were never observed trying to catch any of 
the little fish. Eibl-Eibesfeldt suggests that it 
be ascertained whether the appetite of pre- 
daceous fishes is first appeased before they 
allow themselves to be picked over by the 
smaller fishes. No mention was made of the 
examination of stomach contents for ecto- 
parasites by this author. 
Eibl-Eibesfeldt has informed me in a letter 
that he has since observed " Coris giofredi Risso 
cleaning a Crenilabris ” in the Mediterranean 
south of Naples. 
Szidal and Nani (1951: 412) examined the 
stomach contents of a Remora remora (Lin- 
naeus) from the coast of Argentina and found 
four parasitic copepods of the family Caligi- 
dae, three of them males of Achteinus dentatus 
Wilson and the other a female Pandarus; both 
forms are known to parasitize sharks. 
Hubbs and Hubbs (1954: 194) stated that 
the embiotocid Brachyistius frenatus Gill and 
the labrid Oxyjulis californica (Gunther) have 
at times been observed feeding on ectopara- 
sites of other California fishes. 
The food habit of removal of ectoparasites 
from other fishes represents a distinct bio- 
logical niche. It is interesting to note how 
different species, often from totally different 
families, have filled this niche in different 
areas of the world; however, more of them are 
species of Labridae than of any other family. 
It should be added that primarily tropical and 
subtropical areas, where labrids are usually 
numerous, have been investigated. 
In addition to fishes like Labroides , certain 
shrimps have been observed removing ecto- 
parasites from fishes. In Papetoai Bay and the 
lagoon of Moorea at depths of about 70 feet 
the author watched a shrimp picking at fishes. 
The shrimp was identified as Hippolysmata 
grabhami by Dr. F. A. Chace, Jr. The adult 
shrimp are about 40 to 50 mm. in total body 
length, have a brilliant red band along the 
back which is bisected by a white middorsal 
line, and long white antennae and antennules. 
They were seen on the surface of isolated 
blocks of coral. When fish approached they 
waved their antennae and antennules as if to 
attract the fish. 'Among the fishes seen to 
enter into symbiotic association with this 
shrimp were: Apogon exostigma (Jordan and 
Starks), Apogon sp., Anthias sp., juvenile Acan- 
thurus mata (Cuvier), and Gymnothorax flavi- 
marginata (Riippell) . A shrimp climbed on to 
a two-foot specimen of the latter species and 
busily picked over the dorsal part of the eel’s 
head. 
Labroides bicolor Fowler and Bean 
Fig. 4 
Labroides bicolor Fowler and Bean, 1928, U. S. 
Natl. Mus., Bui. 100, vol. 8: 224, pi. 18. 
type locality: Port Maricaban, Philippine 
Islands. 
Judging from the few locality records of 
the species (Philippines, Java (Hardenberg, 
1936), Japan (Kamohara, 1952), the Gilbert 
Islands (Randall, 1955^), Aldabra, Indian 
Ocean (Smith, 1955)), L. bicolor would ap- 
