148 
ZOOLOGICAL SOCIETY BULLETIN 
SHARK-SUCKER ATTACHED TO A DOGFISH 
Photograph by Elwin R. Sanborn 
Some aquarists complain that it is a bully, 
but we have found it not unfriendly toward the 
killifish, with which it has been kept in our 
laboratory. 
In the breeding season the male assumes a 
ravishing combination of colors: ultra-marine 
blue over the back and sides, with dull orange 
below, a black half-ring round the eye, and 
black touches on the edges of the fins; these 
colors being but temporary embellishments to 
the natural beautiful markings of silver and 
black. I. M. M. 
A Notable Exhibit. — The association of 
shark, shark-sucker and pilot fish described in 
the January number of this Bulletin, con¬ 
tinues to be a fascinating sight at the Aquarium. 
Professor Bateson of Cambridge University, 
a distinguished scientist, who saw it last year, 
pronounced it unique as an aquarium feature. 
He thought it altogether remarkable that these 
three species, always living together in the wild 
state, could be seen in the heart of a great city, 
behaving just as they do in the wide oceans. 
When this strange display of sea life was estab¬ 
lished, the director had no great faith in its 
permanency, but the wholly unrelated numbers 
in the anciently appointed partnership pro¬ 
ceeded at once to act as they had always acted. 
While captivity has modified the behavior of 
the pilots to some extent, the shark-suckers con¬ 
tinue true to form. After more than a year of 
captivity the participants in the performance 
show no sign of dropping out. 
Mr. Sanborn has recently made some re¬ 
markably good photographs of these fishes, 
which are reproduced in this number of the 
Bulletin. Since the shark, shark-sucker and 
pilot fish group was established, a successful 
union of shark-sucker with the small dog shark 
(Mustelus canis ) has been brought about. 
When the former attached itself to the dog 
shark, the latter struggled for hours in the at¬ 
tempt to dislodge it, but finally accepted the 
inevitable. After several months of this inti¬ 
mate association, both species remain in good 
condition. 
In midsummer a six-inch shark-sucker, the 
smallest ever brought to the Aquarium, was 
successfully located with another dog shark. 
Dislodging the shark-sucker seems to be im¬ 
possible. The air disc with which it clings 
takes too firm a hold. C. H. T. 
