4 58 
PACIFIC SCIENCE, Vol. XXI, October 1967 
nothing is known, and a specimen of an un- 
described species of Clibanarius. 
In recent years there has been an increasing 
amount of effort to study the larvae of the 
several families of hermit crabs especially to 
obtain ontogenetic information useful in clas- 
sification and phylogeny of the group. No lar- 
vae of the seven currently recognized species of 
Trizopagurus have been studied previously. The 
purpose of the present work is to provide de- 
scriptions of the zoeae and glaucothoe of this 
tropical eastern Pacific hermit crab based on 
laboratory reared specimens, and to make avail- 
able the limited ecological data obtained inci- 
dental to the rearing experiments. 
ACKNOWLEDGMENTS 
I am indebted to the National Science 
Foundation and to the Institute of General 
Medical Sciences, U. S. Public Health Service 
for their support of this work. Dr. F. M. 
Bayer of this Institute initiated the study by 
bringing an ovigerous female to Miami by air 
from Panama, thus providing the opportunity 
for study at this laboratory of a genus not 
found in the West Indian faunal region. Dr. 
A. L. Rice and C. Edith Marks helped with the 
rearing. Osvaldo Moran-Ribeau did many dis- 
sections and made preliminary study sketches. 
Barbara Stolen made the illustrations. 
METHODS 
Several females were collected in January 
1964 by F. M. Bayer and R. Chesher at sev- 
eral intertidal localities near Venado Island 
in the Bay of Panama off the Canal Zone. One 
female Trizopagurus magni ficus retained her 
eggs during passage back to Miami and yielded 
larvae during 16-18 January 1964. The tem- 
perature of the running sea water in which the 
female was kept was less than 20 °C for one 
week prior to hatching and was 18°C during 
the hatching period. More than 800 larvae 
were obtained from this hatching and were 
placed in plastic compartmented trays as de- 
scribed in previous papers (Provenzano, 1962a; 
Provenzano and Rice, 1964), 1-10 larvae per 
compartment. Trays to which no food was 
added were placed in four experimental tem- 
peratures (10°, 15°, 20°, and 25 °C) to de- 
termine survival time of starved larvae. Addi- 
tional trays, to which Artemia nauplii were 
added as food for the zoeae, were placed at the 
same temperatures. The three lower tempera- 
tures were maintained by thermostatically con- 
trolled refrigerators with fans to circulate air 
within the cabinets so that temperatures during 
the experimental periods did not vary more 
than db0.1°C. For the highest temperature an 
air-conditioning unit in the culture room kept 
air temperature at 25°C=b 1.5°C. 
Two lots of filtered sea water were used dur- 
ing the experiments, 32.6 parts per thousand 
from 16 January-3 February and 35.7 parts 
per thousand from 3 February to termination 
of the experiments. 
Specimens and exuvia were preserved in al- 
cohol or formalin. Specimens were cleared in 
3-5% KOH and whole specimens and exuvia 
were dissected after staining with Mallory’s 
acid fuchsin red, lignin pink, or chlorozol 
black, and were mounted. Study sketches were 
made with a Bausch & Lomb microprojector, 
and details were checked under higher magni- 
fication using a Tasco compound microscope. 
Final drawings were made with the aid of a 
Wild binocular M-5 dissecting scope equipped 
with a camera lucida. 
The term stage is used herein in the sense 
of instar or intermoult. 
All scales in the illustrations represent 0.5 
mm. Carapace length of zoeae was measured 
from the tip of the rostrum to the most pos- 
terior lateral margin of the carapace, not to the 
dorsal posterior margin. Total length was 
measured from tip of rostrum to the median 
posterior margin of the telson exclusive of tel- 
son spines. Because of the flexible nature of 
the abdomen, the total length is less reliable a 
measure than the carapace length, which is 
based on a rigid structure. In the glaucothoes, 
shield length was measured from the tip of the 
rostrum to the cardiac suture. Carapace length 
was taken from the tip of the rostrum to the 
dorsal posterior transverse margin, and total 
length was measured from the tip of the ros- 
trum to the posterior margin of the telson 
exclusive of setae. 
The female from which the larvae were 
