be dissimilar and breeding times may also differ. 

 Detailed studies of the life histories of all the species 

 in this complex are likely to reveal considerable dif- 

 ferences. Unfortunately, the "forms" of P. herbstii, 

 s.L, have been considered a single species and it is 

 seldom possible to determine which "form" (= 

 species) has been used in physiological, ecological, 

 and behavioral experiments (McDonald 1977). The 

 existence of four such similar species over a large 

 range will undoubtedly provide an excellent oppor- 

 tunity for studies of their displacement and compara- 

 tive biology. 



Anthony G. Scheer 



Department of Biochemistry 

 Duke University Medical Center and 

 Duke University Marine Laboratory 

 Beaufort, NC 28516 



National Marine Fisheries Service 

 Systematics Laboratory 

 National Museum of Natural History 

 Washington, DC 20560 



Austin B. Williams 



Acknowledgments 



Our thanks to Darryl L. Felder who was extremely 

 helpful in obtaining several of the forms of P. herbstii, 

 s.L, used in this study, and to anonymous reviewers 

 who suggested improvements in presentation. 



Literature Cited 



McDonald, H. J. 



1977. The comparative intertidal ecology and niche relations 

 of the sympatric mud crabs Panopeus herbstii Milne- 

 Edwards and Eurypanopeus depressus (Smith) at North 

 Inlet, South Carolina, USA (Decapoda: Brachyura: 

 Xanthidae). Ph.D. Thesis, Univ. South Carolina, Colum- 

 bia, 233 p. 

 Rathbun, M. J. 



1930. The cancroid crabs of America of the families Eu- 

 ryalidae, Portunidae, Atelecyclidae, Cancridae and Xan- 

 thidae. U.S. Natl. Mus. Bull. 152, 609 p. 

 Sullivan, B., J. Bonaventura, and C. Bonaventura. 



1974. Functional differences in the multiple hemocyanins of 

 the horseshoe crab, Limulus polyphemus L. Proc. Natl. 

 Acad. Sci. 71:2558-2562. 

 Sullivan, B., L. Pennell, B. Hutchinson, andR. Hutchins. 



In press. Genetics and evolution of the hemocyanin mul- 

 tigene. Comp. Biochem. Physiol. 

 Sullivan, B., and E. Tentori. 



1981. Genetics and evolution of the hemocyanin multigene — 

 II. Absence of genetic variation in Uca from Mex- 

 ico. Comp. Biochem. Physiol. 69B:897-899. 



Turner, K. 



1979. Protein polymorphisms in the mud crabs, Eu- 

 rypanopeus depressus, Panopeus herbstii, forma simpsoni, 

 and Panopeus herbstii forma obesa, at North Inlet, South 

 Carolina (Decapoda: Brachyura: Xanthidae). M.S. 

 Thesis, Clark University, Worchester, Mass., 153 p. 



Turner, K., and T. A. Lyerla. 



1980. Electrophoretic variation in sympatric mud crabs from 

 North Inlet, South Carolina. Biol. Bull. (Woods Hole) 

 159:418-427. 



Williams, A. B. 



1983. The mud crab, Panopeus herbstii, s.l. Partition into six spe- 

 cies (Decapoda: Xanthidae). Fish. Bull., U.S. 81:863-882. 



Bolling Sullivan 



Katie Miller 



Kathleen Singleton 



MUD CRABS OF THE PANOPEUS HERBSTII 

 H. M EDW., S.L., COMPLEX IN 

 ALABAMA, U.S.A. 



The mud crab, Panopeus herbstii, s.l. (sensu Rathbun 

 1930), occupies two distinct habitats in the Mobile 

 Bay region of Alabama — the intertidal marsh and 

 intertidal to subtidal oyster (Crassostrea virginica 

 (Gmelin)) reef (Heard 1982). This paper presents an 

 analysis of morphological attributes and ecological 

 associations of these mud crabs, showing that the 

 populations observed correspond to two sympatric 

 species, P. obesus Smith and P. simpsoni Rathbun 

 (Williams 1983). 



Methods 



Collection of mud crabs for morphological com- 

 parisons and feeding experiments was limited to 14 

 stations along southwestern Mobile Bay, Ala., and 

 nearby eastern Mississippi Sound, from Dog River to 

 Point of Pines, including Dauphin Island (Fig. 1), 

 where P. herbstii, s.L, commonly occurs in a salinity 

 range of 14 to > 20 ppt (May 1974). Figure 1 shows 

 the location of stations which were sampled for crabs 

 before destructive Hurricane Frederick struck in 

 September 1978. The crabs, most numerous in 

 waters with salinity >20 ppt, were sampled on four 

 general types of substrate as follows: 1) Intertidal 

 rubble (pieces of broken concrete over shell hash and 

 silty sand at stations 1, 3, 4, 5, and oyster shell beach 

 at station 2); collected by hand and in small mesh net 

 from beneath pieces of cover. 2) Undercut marsh 

 (mud eroded from beneath floating overhang of 

 vegetation at edge of marsh leaving mat still attached 

 to marsh sod at stations 6,7,8); overhanging mat was 

 partly cut from bank with shovel and flipped over 

 onto marsh to expose roots from which many small 

 and some larger crabs were collected, mat then 

 returned to water. 3) Mud bank (banks of hard mud 



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