PROGRESS IN BIOLOGICAL INQUIRIES, 1936 37 
Results obtained during three extensive surveys of the entire Long 
Island Sound in 1935 had indicated that the relative density of the 
starfish population at different depths and in different areas remains 
the same throughout the year. Therefore, it was quite apparent that 
no general migration of starfish occurs at any particular time during 
the annual cycle. To obtain further evidence on this problem, how- 
ever, systematic observations were made on the starfish population of 
a specific area. Twenty sampling stations were established in the 
region between Stratford Point and Welch’s Point. These stations 
were arranged in four rows of five stations each, corresponding to 
four selected depths of 10, 20, 30, and 40 feet. Observations were 
made once or twice a month throughout the year. 
Analysis of data thus obtained indicates the stability of the star- 
fish population over the 20-square-mile area under observation. Of 
the 13 surveys made, 9 showed the largest number of animals at. 
the 20-foot level, 2 at the 30-foot, and 2 at the 40-foot levels.’ Pre- 
dominance of starfish at certain depths cannot be correlated with 
any seasonal changes. On two occasions at different seasons of the 
year they were found more abundant at the 40-foot level than at 
other depths, once in March and once in the middle of July. Starfish 
were never found in predominating numbers at the 10-foot level. 
This significant fact disproves the idea that normally a regular in- 
shore migration occurs during the prespawning time. In general, the 
observations in the chosen area corroborate the conclusions reached 
during the three extensive surveys of the entire Long Island Sound; 
namely, that the starfish are usually most numerous at the 20-foot 
depth, and that there is no definite inshore or offshore migration 
during different seasons of the year. 
In addition to the regular surveys, a new method of studying the 
movements of the starfish population by releasing large numbers 
of stained animals was applied. It has been found that specimens 
dipped for a minute in a 1 percent solution of nile-blue sulphate ac- 
quire a distinct blue color which is retained for more than 9 months. 
In November 1935, about 12,000 stained starfish were liberated on 
an oyster bed in approximately 15 feet of water. Arrangements were 
made with local oystermen to report the finding of every blue starfish 
with the date and exact location of recovery. By the end of August 
1936, the Bureau and the oystermen, chiefly the Connecticut Oyster 
Farms Co., had recovered 287 blue starfish. 
Reports show that the farthest distance traveled by any of the 
animals was approximately 5,000 feet, or less than 1 nautical mile, 
and that they have a tendency to stay in more or less the same depth 
of water, apparently preferring 15 to 25 feet. As disclosed by these 
observations the movements of the starfish take place in all directions 
and appear to be irregular and reversible. The speed of migration 
is probably controlled by the abundance or scarcity of food, being 
more rapid when food is scarce. 
These and previous studies indicate that starfish distribution is 
correlated with the presence of food. Starfish show no apparent 
preference for any particular species of mollusks, but seem to be 
equally satisfied with oysters, any of several species of clams, mussels, 
or other mollusks. The inequality of the starfish populations of the 
eastern and western parts of the Sound is immediately comprehen- 
