Occurrence of Protohydra leuckarti in Puget Sound 
Wolfgang Wieser 1 
Since the hydrozoan Protohydra leuckarti 
Greeff has always been considered an animal 
of great taxonomic and morphological in- 
terest, its discovery on the Pacific coast of 
North America deserves notice. This is the 
first record of the species for the Pacific Ocean. 
It was reported once before from the Pacific 
area, from a lake — probably a brackish one 
—in Kamtchatka (Abonyi, 1929). 
My specimens are derived from two sand 
beaches on Puget Sound in the state of 
Washington, viz., from "Golden Gardens,” 
within the city limits of Seattle on the east 
side of the Sound, and from Vashon Island 
farther south in the Sound. The species occurs 
in the lower intertidal zone of the beaches 
1 Recent I.C.A. Fellow, Department of Zoology, 
University of Washington, Seattle, Washington. Pres- 
ent address: Department of Zoology, University of 
Vienna, Vienna 1, Austria. Manuscript received June 
13 , 1956 . 
(from —1 to +3 feet), sometimes in con- 
siderable numbers. It was found in October 
1955 and January 1956 at Golden Gardens, 
in May 1956 on Vashon Island. The sand is 
medium fine at the former locality, fine at the 
latter. A mechanical grain analysis of the two 
substrata gave the following results: 
Golden 
Vashon 
Gardens 
Island 
4760-2362ju . 
. . . 10.9% 
0.1% 
2362-1 190^ . 
. . . 13.3 
0.3 
1190- 589 ix . 
. . . 44.9 
2.7 
589- 295m - 
. . . 26.8 
19.1 
295- 149m- 
3.9 
61.7 
< 149m • 
16.1 
The surface water of Puget Sound is of 
slightly reduced salinity; it varies from less 
than 27.5°/oo in April and May to 30°/oo 
in autumn months. This is true also for the 
central portion of Puget Sound. The water 
Fig. 1 . a and b: Two different stages of contraction of the same specimen of Protohydra leuckarti (photomicrograph 
from life by Pat Dudley). Note the globular swelling at the anterior end in a. This is a typical stage after a wave 
of contraction has travelled through the animal from back to front, c: Stenotele (penetrant), d: isorhizas (gluti- 
nants), from an alcohol-fixed specimen. 
106 
