The Ecology of the Replacement of Pseudosquilla ciliata (Fabricius) by 
Gonodactylus jalcatus (Forskal) (Crustacea; Stomatopoda) Recently 
Introduced into the Hawaiian Islands 1 
Robert A. Kinzie III 2 
Although knowledge of the Hawaiian sto- 
matopods was summarized by Townsley in 1953, 
the occurrence of a species of Gonodactylus 
not previously recorded from Hawaii (Kinzie, 
1965) indicated a possible introduction and 
necessitated a revision of information on this 
group in Hawaii. 
Previous workers, when discussing the Ha- 
waiian stomatopods (Brooks, 1886; Bigelow, 
1931 ; Edmondson, 1921 ; and Townsley, 1953), 
all indicated that Pseudosquilla ciliata (Fabri- 
cius) was the most common species. It was re- 
corded as occurring on sand and mud flats as 
well as in coral heads. The only record of Gono- 
dactylus from Hawaii before 1965 was G. 
guerini White, but this species was taken from 
deep water (Brooks, 1886; Edmondson, 1921; 
Townsley, 1953). 
The stomatopod fauna of Hawaii prior to 
1953 can be characterized as follows: Pseudo- 
squilla ciliata was the dominant shallow water 
stomatopod. It was found in sand and mud flats, 
and was also the most common species living in 
dead coral heads. P. ciliata and occasional P. 
oculata Brulle (Townsley, 1953), were the only 
large (over 3 cm) stomatopods found living in 
coral heads. 
In 1954, Townsley (personal communication) 
observed that a species of Gonodactylus was 
found in dead coral heads in Kaneohe Bay and 
on the reef at Waikiki. In 1958, Okamoto (in 
an unpublished class report at the University of 
Hawaii) reported two species of stomatopods 
1 Contribution No. 312, Hawaii Institute of Marine 
Biology, prepared as partial fulfillment of requirements 
for the Master of Science degree, University of 
Hawaii. The research was supported in part by grants 
GB-1003 and GB-3651 from the National Science 
Foundation to Dr. E. S. Reese and the Eniwetok 
Marine Biological Laboratory. Manuscript received 
November 13, 1967. 
2 Present address: Department of Biology, Yale 
University, New Haven, Connecticut 06520. 
that had not been described from the Hawaiian 
Islands. One was G. hendersoni Manning (as 
G. demanii Henderson), four specimens of 
which were taken in a fresh state from the 
stomach of one Neothunnus macropterus (Yel- 
lowfin tuna) caught near Oahu. The other spe- 
cies was Gonodactylus jalcatus (Forskal) . 
Collections on the reefs at Waikiki in 1963 
yielded a number of large G. jalcatus as well as 
G. hendersoni. Further collections at other areas 
(Figs. 1 and 2) indicated that G. jalcatus was 
by far the most abundant stomatopod in dead 
coral heads and G. hendersoni was fairly com- 
mon in some areas. On the other hand, Pseudo- 
squilla ciliata was not found in dead coral heads, 
but it was still abundant living within burrows 
in sand and mud flats. 
From these facts it appears that the coral 
head habitat, once almost exclusively occupied 
by P. ciliata , was taken over completely by Gono- 
dactylus jalcatus in about nine years. This paper 
describes some of the results obtained while in- 
vestigating this hypothesis and studying the 
origins, possible mode of introduction, and me- 
chanism of replacement of Pseudosquilla ciliata 
by Gonodactylus jalcatus. 
DISTRIBUTION AND NOTES ON DESCRIPTION OF 
NEW HAWAIIAN SPECIES 
Gonodactylus jalcatus (Forskal) 
A synonymy of G. jalcatus is given by Hol- 
thuis (1941). 
distribution: G. jalcatus is widely distri- 
buted through the Indo-Pacific, ranging from 
the Red Sea (Forskal, 1775; Ingle, 1963) 
through the Indian Ocean to western Australia 
(Stephenson, 1962), northward to the Ryukyu 
Islands (Fukuda, 1910), Sagami Bay (Utinomi, 
1961), and Tusima and Ogawara islands (Ko- 
mai, 1927). G. jalcatus occurs in the Pacific in 
Queensland (Stephenson, 1953), the Bonin 
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