Figure 1
Anatomy of a brachyuran crab, Callinectes sapidus, with grooming appendages and groomed body regions labelled. Morphological structures are similar to Menippe mercenaria except for p1, p5, and gills (in Menippe, p1 is larger, p5 is similar to p4, and there are nine gills in a slightly different orientation). A. Dorsal body. B. Ventral body. C. Dorsal view of the internal branchial cavity with most of carapace removed, showing eight gills and three epipods. D. Third maxilliped morphology, with the palp (comprised the dactyl, propodus, and the carpus); the basis and the coxae are combined in the protopod. Note: 1-8=gill 1-8; a1=antennule, a2=antenna, abd=abdomen, ant=anterior, b=basis, c=carapace, ca=carpus, co=coxae, d=dactyl, e=eyes, ep1-3=epipod associated with maxillipeds, i=ishchium, l=lateral, m=merus, me=medial, p=propodus, pa=palp, post=posterior, pr=protopod, p1=cheliped, p2-p5=walking legs, 3m=third maxilliped. Note: Body positions noted in parentheses. Figs. 1A-D modified from Kennedy and Cronin (2007).
Figure 2
Grooming appendages of blue and stone crabs for individual observations (30 min trial). Decimal places were used to show exact data; rounding would have led to many “0”. A. The 3mxp is the most frequently used grooming appendage in both crab species. B. The 3mxp is the grooming appendage used for the most time, along with the walking legs and the cheliped. Note: 1mxp=first maxilliped, 2mxp=second maxilliped, 3mxp=third maxilliped, AO=alternative objects, BC=blue crabs, SC=stone crabs.
Figure 3
Groomed body regions of blue and stone crabs for individual observations (30 min trial). A. The gills, antennae, antennules, and maxillipeds are the most frequently groomed body regions for both species. B. The gills, carapace, walking legs, chelipeds, and antennae are groomed for the longest time periods in both species. Note: 1mxp=first maxilliped, 2mxp=second maxilliped, 3mxp=third maxilliped, A1=antennules, A2=antennae, AO=alternative objects, BC=blue crabs, SC=stone crabs.
Figure 4
Grooming of functional body regions in blue and stone crabs for individual observations (30 min trial). A. Respiratory structures (gills) are groomed more often than sensory structures (antennules, antennae, eyes, and third maxillipeds) in both crab species. B. Time-wise, stone crabs groomed their respiratory organs more than sensory structures, but blue crabs groomed these two functional regions equally. Note: BC=blue crabs, SC=stone crabs.
Figure 5
Agonistic behaviors in blue and stone crabs (30 min trial). A. Grooming was the most frequent behavior for both species. B. Both crab species spent more time grooming, followed by fighting and displaying. Note: BC=blue crabs, SC=stone crabs.
Figure 6
Scanning electron microscope images of gill fouling in blue (gill #6) and stone crabs (gill #7). A. Blue crab dorsal side of gill, with all grooming appendages present, showing minimal fouling, and simple setae along the central axis. B. Blue crab ablated-side of dorsal gill, with third epipod removed, showing evidence of fouling along the central axis, between lamellae, and covering setae. C. Intact blue crab, side of ventral gill, showing minimal fouling levels and visible simple setae. D. Blue crab ablated-side of ventral gill showing fouling along the central axis, in between lamellae, and covering the simple setae. E. Stone crab, side of ventral gill, with all grooming appendages present, showing minimal fouling. F. Stone crab ablated-side of ventral gill with third epipod removed, showing evidence of fouling between lamellae with fouling protruding from a singular lamellae. G. Intact stone crab gill showing low fouling levels between lamellae. H. Stone crab with ablated grooming appendage, showing fouling along the dorsal central axis and between lamellae.
Figure 7
Grooming time budgets in crustaceans, in individual observations, with blue and stone crab data from this research. Note: Macrobrachium rosenbergii (Wortham et al., 2014VanMaurik, L.N. and Wortham, J.L. 2014. Grooming as a secondary behavior in the shrimp Macrobrachium rosenbergii (Crustacea, Decapoda, Caridea). ZooKeys, 457: 55.), Macrobrachium grandimanus (VanMaurik and Wortham, 2011VanMaurik, L.N. and Wortham, J.L. 2011. The Grooming Behaviors of the Hawaiian River Shrimp, Macrobrachium grandimanus. Journal of Crustacean Biology, 31: 617-622.), Heptacarpus pictus (Bauer, 1981Bauer, R.T. 1981. Grooming behavior and morphology in the decapod Crustacea. Journal of Crustacean Biology, 1: 153-173.), stomatopods (Bauer, 1987Bauer, R.T. 1987. Stomatopod grooming behavior: functional morphology and amputation experiments in Gonodactylus oerstedii. Journal of Crustacean Biology, 7: 414-432.; Wortham, 2008Wortham, J.L. 2008. Grooming in mantis shrimp. p. 119. In: Society for Integrative and Comparative Biology. Abstract volume 2 from the Annual Meeting in San Antonio, Texas, USA. ), Lithodes maja (Pohle, 1989Pohle, G. 1989. Gill and embryo grooming in lithodid crabs: comparative functional morphology based on Lithodes maja. Crustacean Issues , 6: 75-94.), Libinia dubia (Jedlicka and Wortham, 2014Jedlicka, J. and Wortham, J.L. 2014. Grooming behaviors in the spider crab Libinia dubia. Florida Scientist, 77: 33-34. ).