Adult and Larval Stomatopod Crustaceans 
Occurring in Hawaiian Waters^ 
Sidney Joseph Townsley^ 
INTRODUCTION 
The Stomatopoda constitute the only order 
belonging to the division Hoplocarida of the 
malacostracan Crustacea. All living forms are 
included in a single family, the Squillidae, 
whose characteristics are the same as those 
of the order. The order, according to Bigelow 
(1894), may be defined as Crustacea which 
have these characteristics: the stalked eyes and 
antennules are borne upon distinct movable 
segments; the adult rostrum is separated from 
the carapace by a movable joint; the carapace 
is small and does not cover the last four tho- 
racic somites; the first five pairs of thoracic 
appendages are not biramous and serve as 
accessory mouth parts, with the second pair 
strongly developed into large raptorial limbs ; 
the last three pairs of thoracic appendages 
are adapted for walking, are biramous and bear 
a lateral segment upon the penultimate seg- 
ment; the abdomen is well developed; fila- 
mentous gills are carried upon the exopod of 
the first five abdominal appendages; the sixth 
abdominal appendages, the uropods, with the 
telson, act as a powerful tail fan. 
At the present time the six recognized gen- 
era have a world-wide distribution, being 
found in the tropical, subtropical, and tem- 
perate waters of the Atlantic, Pacific, and In- 
dian oceans. All six genera are represented in 
the Hawaiian fauna. Edmondson (1921), re- 
porting upon the stomatopods in the collec- 
^ Contribution No. 37, Hawaii Marine Laboratory, 
Prepared as partial requirement for the M.S. degree. 
University of Hawaii. Manuscript received November 
14, 1951. 
^ Graduate assistant, Osborn Zoological Laboratory, 
Yale University. 
tion of the Bernice P. Bishop Museum, found 
six genera and eight species from Hawaii: 
Squilla oratoria, 5. alha, Pseudosquilla ciliata^ 
P. oculata^ Coronida sinuosa, Lysiosquilla macu- 
lata, Odontodactylus hanseni, and Gomdactylus 
guerini. Since that time no extensive studies 
have been made on specimens from Hawaii, 
but occasional reports of previously recorded 
species from this region have found their way 
into the literature. In addition to these eight 
species which have been again collected dur- 
ing the progress of this study, I have found 
two species which have not been recorded 
from this region previously, namely, Squilla 
hoops and an undescribed species of Squilla. 
Stomatopods are usually found in very shal- 
low water, but some species occur at greater 
depths. I have collected Gomdactylus guerini 
in Hawaii only at depths over 100 meters, and 
Kemp ( 1913 ) reports that Squilla leptosquilla 
was dredged by the "'Investigator” at a depth 
of 370-419 fathoms. The adults are bottom 
dwellers where they may burrow into the sub- 
strate or inhabit crevices in coral. They are 
seclusive in their habits and during the day 
are usually found either in their burrows or 
but a short distance away. At times they wan- 
der some distance from their burrows, as is 
shown by the fact that they are occasionally 
captured in crab nets and at submersible lights 
used for collecting at night. Inasmuch as the 
burrows are quite deep (a foot or more below 
the surface), and because the animals retire 
to the bottom of them at the least alarm, 
stomatopods are quite difficult to collect; 
consequently, the group has been studied 
very little, the most notable works being those 
399 
