Table 1.
Species examined (column 1), sample size (column 2), GPS coordinates of sampling location (column 3), mean Slope (and standard error) of the allometric log-log relationship where M is for male and F is for female crabs (column 4), mean Intercept (and standard error) of the log-log allometric relationship where M is for male and F is for female crabs (column 5), Genbank accession numbers for 16S rRNA data used in constructing the phylogenetic tree (column 6).
Only a single slope and intercept are given when the allometric relationship did not differ between males and females (α = 0.05). The slope and intercept for each of the relationships given is highly significant (P < 0.0001).
Fig 1.
Log stomach volume (mm3) as a function of log dry body mass (g) for 15 species of brachyuran crab.
Black circles are male and red are female.
Fig 2.
Log stomach volume (mm3) as a function of log dry body mass (g) for A. pisonii (A), and O. quadrata (B). For both, circles are males, squares are females. For A. pisonii, black are from a dock habitat, red are from a saltmarsh habitat, and blue are from a mangrove habitat. For O. quadrata, disturbance levels of beaches are pristine (black), moderately impacted by humans (red), heavily impacted by humans (blue), heavily impacted by humans and vehicles (green).
Fig 3.
Relationship between the slope of the ontogenetic allometric relationship between log stomach volume and log dry body mass and several ecological factors.
Percent herbivory in the diet is shown on the x-axis. Activity levels of crabs were binned for graphical presentation and are shown by the symbol shape, with squares indicating species that are relatively inactive, circles indicating species that are moderately active, and triangles indicating species that are highly active. Numbers next to symbols indicate the species/gender/habitat as follows: 1 –A. pisonii mangrove male; 2 –A. pisonii mangrove female; 3 –A. pisonii marsh male; 4 –A. pisonii marsh female; 5 –A. pisonii dock; 6 –A. cinereum; 7 –C. sapidus; 8 –C. irroratus; 9 –C. maenas male; 10 –C. maenas female; 11 –D. sayi; 12 –E. depressus; 13 –E. limosum; 14 –H. sanguineus male; 15 –H. sanguineus female; 16 –P. herbstii male; 17 –P. herbstii female; 18 –P. obesus male; 19 –P. obesus female; 20 –R. harrisii male; 21 –R. harrisii female; 22 –S. reticulatum; 23 –U. minax; 24 –U. pugilator male; 25 –U. pugilator female; 26 –U. pugnax; 27 –O. quadrata pristine; 28 –O. quadrata medium human impact; 29 –O. quadrata high human impact; 30 –O. quadrata high human impact + vehicles.
Fig 4.
Phylogenetic relationship between crabs used in this study based on overlapping regions of 16S rRNA.
The size of the text for the species name gives the slope of the allometric relationship for stomach volume vs. dry body mass (see reference values given on left-hand side of figure for numerical values of different relative sizes), while the color of the text for the species name gives the value of the intercept based on the scale bar shown above the phylogenetic tree. Decimal values given below each branch indicate the branch length, while the whole numbers next to each node indicate bootstrap percentages based on 1,000 bootstrap replicates.
Fig 5.
Relationship between the intercept of the ontogenetic allometric relationship between log stomach volume and log dry body mass and multiple ecological factors.
Percent herbivory in the diet is shown on the x-axis. Symbol size indicates the relative maximum size of the group or species. Symbol shapes and numbering are as described in Fig 3.