475 
Abstract— Lake Maracaibo, a large 
Venezuelan estuarine lagoon, is report- 
edly inhabited by three species of the 
genus Callinectes Stimpson, 1860 that 
are important to local fisheries: C. sapi- 
dus Rathbun, 1896, C. bocourti A. Milne 
Edwards, 1879, and C. maracaiboensis 
Taissoun, 1969. Callinectes maracai- 
boensis, originally described from Lake 
Maracaibo and assumed endemic to 
those waters, has recently been reported 
from other Caribbean localities and 
Brazil. However, because characters 
separating it from the morphologically 
similar C. bocourti are noted to be 
vague, we have compared these spe- 
cies and several congeners by molec- 
ular methods. Among our specimens 
from Lake Maracaibo and other parts 
of the Venezuelan coast, those assign- 
able to C. bocourti and C. maracaiboen- 
sis on the basis of putatively diagnostic 
characters in coloration and structural 
characteristics do not differ in their 
16S mtDNA sequences. These molec- 
ular results and our re-examination 
of supposed morphological differences 
between these species suggest that C. 
maracaiboensis is a junior synonym of 
C. bocourti, which varies markedly in 
minor features of coloration and struc- 
tural characteristics. Genetic relation- 
ships of this species to other species 
of swimming crabs of the genus Calli- 
nectes are also explored and presented 
as phylogenetic trees. 
Manuscript accepted 21 March 2001. 
Fish. Bull. 99:475-481 (2001). 
Lack of divergence between 16S mtDNA sequences 
of the swimming crabs Callinectes bocourti 
and C. maracaiboensis (Brachyura: Portunidae) 
from Venezuela* 
Christoph D. Schubart 
Department of Biology 
University of Louisiana 
Lafayette, Louisiana 70504 
Present address: Biologie I, Universitat Regensburg 
93040 Regensburg, Germany 
E-mail address: christoph.schubart@biologie.uni-regensburg.de 
Jesus E. Conde 
Carlos Carmona-Suarez 
Centro de Ecologia 
Instituto Venezolano de Investigaciones Cientfficas (IVIO 
A P. 21827 
Caracas 1020-A, Venezuela 
Rafael Robles 
Darryl L. Felder 
Department of Biology 
University of Louisiana 
Lafayette, Louisiana 70504 
Swimming crabs of the genus Calli- 
nectes Stimpson, 1860 are widely dis- 
tributed throughout the American trop- 
ics and subtropics, where many species 
are exploited commercially (Norse, 1977; 
Williams, 1984). Members of this genus 
play key trophic roles in coastal habitats 
that range from sandy-mud bottoms to 
seagrass meadows (Arnold, 1984; Orth 
and van Montfrans, 1987; Wilson et al., 
1987; Lin, 1991). Of the nine species 
of Callinectes from the tropical western 
Atlantic, seven have been reported from 
western Venezuela (Rodriguez, 1980; 
Williams, 1984; Carmona-Suarez and 
Conde, 1996). However, knowledge of 
these Venezuelan populations remains 
inadequate, despite the importance of 
several species in both large-scale com- 
mercial harvests and artisanal fish- 
eries of coastal villages in the area 
(Oesterling and Petrocci, 1995; Ferre r- 
Montano, 1997; Conde and Rodriguez, 
1999). Persistent difficulty in identify- 
ing mixed samples of these species ham- 
pers understanding of their distribution, 
abundance, and population dynamics, 
which are essential to fishery-manage- 
ment decisions. In particular, consistent 
morphological distinction of the com- 
monly encountered C. bocourti from C. 
maracaiboensis cannot be achieved with 
confidence. 
Initially described as endemic from 
Lake Maracaibo, C. maracaiboensis 
has been reported from other Vene- 
zuelan waters, as well as from sites 
in Jamaica, Curasao, Colombia, and 
Brazil (Norse, 1977; Carmona-Suarez 
and Conde, 1996; Sankarankutty et al., 
1999). Although detailed descriptions 
have been provided by Taissoun (1969, 
1972) and Williams (1974) to diagnose 
C. maracaiboensis, the same authors 
have repeatedly emphasized its resem- 
blance to C. bocourti. Morphological 
distinction of the two species is based 
upon postulated defining characters of 
the frontal teeth, direction and form of 
* Contribution 75 of the University of Lou- 
isiana Lafayette, Laboratory for Crusta- 
cean Research, Lafayette, LA 70504. 
