Revista Chilena de Historia Natural 77 (1): 15-27, 2004
RESEARCH ARTICLE
Latitudinal comparisons of reproductive traits in five Brachyuran species along the Chilean
coast
ANTONIO BRANTE, SANDRA CIFUENTES, HANS-OTTO PÖRTNER, WOLF ARNTZ & MIRIAM
Understanding large-scale patterns in reproductive investment and fecundity of marine
invertebrates is important for determining the critical environmental variables affecting reproduction and thus, the spatial patterns of
population dynamics. However, information on patterns of reproduction of marine invertebrates at large spatial scales are either
scarce, or have been conducted by mixing species with contrasting modes of development. Brachyuran crabs are an ideal group to
analyze large-scale patterns of reproduction not only because many species are commercially exploited, but also because they show a
single mode of larval development and wide distributional ranges. Here, we report latitudinal patterns of reproductive variables in five
Brachyuran crab species along the coast of Chile (18-54°S): Cancer setosus, Paraxanthus barbiger, Homalaspis
plana, Ovalipes trimaculatus, and Taliepus marginatus. Five variables were analyzed: brood weight, fecundity,
embryo dry weight, embryo volume, and embryo loss. Comparisons between northern (20º S), central (29-33º S) and southern Chile
(35-41º S) were conducted for C. setosus and between central and southern Chile for the other four species. A total of 378
brooding females were collected and analyzed. Although we did not find a clear and consistent pattern in all reproductive variables in
the five crab species analyzed along the coast of Chile, generalizations can be drawn from this study. First, brood weight did not vary
between central and southern Chile in most of the species (except P. barbiger). Second, embryo loss did not vary
between central and southern Chile in four of the species studied. Third, embryo dry weight tended to increase toward high latitudes in
four of the five species. We suggest that the costs associated to oxygen provision to broods may explain some of the patterns found,
but other factors need also be considered.
reproductive
investment, fecundity, brooding, crabs, embryo loss
