The Larval Development of the Crab, Cyclograpsus cinereus Dana, 
under Laboratory Conditions 1 
John D. Costlow, Jr . 2 and Elba Fagetti 3 
Early descriptions of larvae of the Grap- 
sidae, based largely on material from the plank- 
ton and frequently limited to the first zoeal 
stage, suggested considerable uniformity in the 
morphological characteristics of larvae of this 
group of crabs (Hyman, 1924). Subsequent 
descriptions, based on plankton material as well 
as on material obtained from rearing the larvae 
in the laboratory, have served to point out cer- 
tain differences which do exist in the larvae of 
this group (Aikawa, 1929; Hart, 1935). To 
date, however, a very limited number of larvae 
of crabs belonging to the family Grapsidae have 
been described. 
Within the subfamily Sesarminae larvae of 
two species of the genus Sesarma have been de- 
scribed from rearing under laboratory conditions 
(Costlow and Bookhout, I960, 1962). These 
two species, S. cinereum and S. reticulatum , 
while relatively common along the east coast of 
North America and even extending as far as 
Venezuela, are not known from the west coast 
of North or South America. 
On the west coast of Chile, crabs of the sub- 
family Sesarminae are limited to two species of 
Cyclograpsus : C. cinereus Dana and C. punc- 
tatus Milne Edwards (Garth, 1957). The larvae 
of these species have not been described, either 
from rearing or from the plankton, and nothing 
is known about the effect of environmental fac- 
tors on the development of the larval stages. 
The present study has had two main objec- 
tives: one, to rear the larvae of Cyclograpsus 
cinereus Dana and provide a description of all 
developmental stages; and two, to determine if 
salinity and temperature affect the survival and 
duration of the larval stages. 
1 These studies were supported by a grant (GB 
1699) from the National Science Foundation and, in 
part, through the Exchange of Scientists Program of 
the Pan American Union, Organization of American 
States. Manuscript received February 9, 1966. 
2 Duke University Marine Laboratory, Beaufort, 
North Carolina. 
3 Estacion de Biologia Marina, Vina del Mar, Chile. 
METHODS 
Ovigerous Cyclograpsus cinereus females 
were obtained in the vicinity of the Marine 
Biological Station, Montemar, University of 
Chile, and flown by air to the Duke University 
Marine Laboratory, Beaufort, North Carolina. 
The crabs were transported in sea water, salinity 
34.4 ppt, and extreme temperature changes 
were avoided by packing them in thermos con- 
tainers. On arrival at Beaufort, the females 
were retained at 35 ppt, 20° C. At the time of 
hatching the larvae were removed, segregated 
into series of 50 or 100 larvae, and maintained 
at the temperature-salinity combinations shown 
in Table 1. Within each temperature-salinity 
series the larvae were further subdivided, 10 
zoeae per bowl, and were fed Artemia nauplii 
and Arbacia eggs. Each day the larvae were 
moved to freshly filtered sea water in clean 
bowls and fresh food was added. At this time 
the bowls were examined for exuviae, the dead 
larvae were removed, and the number was re- 
corded. When the megalops stage was reached 
the larvae were maintained individually in plas- 
tic compartmented boxes and fed only Artemia 
nauplii. 
From mass cultures the larvae and exuviae 
were preserved in 5% formalin at known stages 
of development. Drawings were made to scale 
with the aid of a camera lucida and the chroma- 
tophore pattern was determined from living 
larvae. 
RESULTS 
Larval Stages 
There are five zoeal stages and one megalops 
stage in the complete development of C. cine- ; 
reus. The major characteristics of each larval 
stage are as follows: 
first zoea (Fig. 1 , A-I) : The cephalotho- 
rax has a gibbose dorsal spine which curves 
caudally (Fig. 1 , A). The rostral spine is short 
and the carapace is devoid of lateral spines. 
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