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PACIFIC SCIENCE, Vol. XV, April 1961 
four other species, which hatched 12-16 days 
after spawning. 
In laboratory cultures, many of the veligers 
(up to 75 per cent) did not succeed in escaping 
from the capsules. However, this may have been 
due to the abnormal spatial position of the de- 
tached capsules; it is less likely to occur in na- 
ture. It has been noted above that the capsules 
are usually affixed to the underside of a rock. 
Since the exit window is thus oriented down- 
ward in nature, escape of the larvae from the 
capsule may be facilitated by gravity after dis- 
appearance of the membrane covering the exit 
window. However, in laboratory cultures in 
which capsules were oriented as shown in Fig- 
ure 1, larvae ready to hatch were often observed 
crowded toward the exit window before dis- 
solution of the membrane, and many escaped 
from the capsule by actively swimming upward. 
These observations suggest that positive or neg- 
ative geotropism is not a factor in the hatching 
of Conus larvae. 
The length of the pelagic stage could not be 
determined except for C. pennaceus , in which it 
is only 1 day or less. The maximum survival 
time of free-swimming veligers in the writer’s 
laboratory was 13 days (C. rattus) . Partial me- 
tamorphosis was observed only in C. pennaceus. 
The nature of the food of the larval stages is 
unknown. Protozoa abounded in the cultures. 
Thorson (1946) concluded that all prosobranch 
larvae known from the 0resund feed on phy- 
toplankton, and he calculated the theoretical 
maximum diameter of the food to be 5-45 g. 
The mouths of Conus veligers measured were of 
about the same diameter as the esophagus of 
the smaller larvae measured by Thorson. Thus 
the larvae of Conus probably depend for food on 
phytoplankton, nannoplankton, and detritus. 
Examination of squash preparations of C. pen- 
naceus a few days after settling revealed the 
presence of radula teeth. These differ in form 
from the adult teeth, being shorter in propor- 
tion to the thickness, and they are probably not 
functional. The method of feeding, as well as 
the food, is thus not known at this stage of the 
life history. The rather fragmentary information 
available on post-larval development and growth 
of Conus in Hawaii has been reported elsewhere 
(Kohn, 1959 b) . 
SUMMARY 
Egg capsules of 9 of the 33 species of Conus 
found in Hawaii are described and figured. In- 
terspecific variation is usually not sufficient to 
permit identification of the species to which an 
egg mass belongs in the absence of the parent. 
The complete course of larval development 
within the egg capsule from spawning (un- 
cleaved egg) to hatching (veliger or velicon- 
cha) is described for 4 species. Early cleavage 
stages occur 1-3 days after spawning, suppressed 
trochophore stage at 2-6 days, and veliger stage 
at 6-10 days. Freely swimming veligers hatched 
from egg capsules of 3 species 14-15 days after 
oviposition, in agreement with the develop- 
mental time scale of other species of Conus 
previously reported on by Ostergaard (1950). 
All species found to have pelagic larval stages 
produced large numbers (15,000-210,000) of 
small (125-225 eggs. It was not possible to 
determine the length of the free-swimming stage 
in any of these species. 
Hatching in one species, C. pennaceus , occurs 
16-26 days after oviposition at the advanced 
veliger or veliconcha stage. The larvae swim 
about for 1 day or less and then assume the 
benthic habit and begin metamorphosis. This 
species produces small numbers (3,500) of 
large (460 g) eggs. This characteristic is cor- 
related with the absence of a long pelagic larval 
stage. 
ACKNOWLEDGMENTS 
This study was aided by a grant from the 
Sigma Xi-RESA Research Fund, 1959. It was 
carried out at the Hawaii Marine Laboratory of 
the University of Hawaii and the Marine Bio- 
logical Laboratory of the University of Copen- 
hagen. The writer is extremely grateful to Prof. 
Gunnar Thorson for providing laboratory facil- 
ities at the latter institution, access to unpub- 
lished data, and stimulating discussions, and for 
arranging for the services of Mr. P. H. Winther, 
who drew Figures 2, 4-9, 11, 13, and 14. The 
other figures were prepared by the author from 
sketches of living specimens and from camera 
lucida drawings of fixed material. Appreciation 
is also expressed to the staffs of the two labora- 
tories mentioned above for much helpful as- 
sistance. 
