Grooming behaviors and gill fouling in the commercially important blue crab (Callinectes sapidus) and stone crab (Menippe mercenaria)

Abstract

Grooming behaviors reduce fouling of body regions. In decapods, grooming time budgets, body regions groomed, and grooming appendages are known in several species; however, little data exists on brachyuran crabs. In this study, grooming behaviors of two commercially important crabs were documented (blue crabs: Callinectes sapidus Rathbun, 1896; stone crabs: Menippe mercenaria Say, 1818). These crabs are harvested by fishermen and knowing their grooming behaviors is valuable, as clean crabs are preferred by consumers and the stone crab fishery consequence of removing one cheliped to grooming behaviors is unknown. Crabs were observed individually and agonistically to determine how grooming behaviors vary in the presence of another conspecific. Both species frequently use their maxillipeds and groom, with the gills being cleaned by epipods. Respiratory and sensory structures were groomed frequently in both species. Removal of a grooming appendage resulted in higher fouling levels in the gills, indicating that grooming behaviors do remove fouling. Overall, stone crabs had a larger individual time budget for grooming, but agonistic grooming time budgets were similar. Stone crab chelipeds are used in grooming, especially cleaning the other cheliped. The chelipeds are not the main grooming appendage; however, implications of losing one cheliped may have large impacts.

Grooming behaviors and fouling of the spider crab Libinia dubia (Decapoda: Epialtidae)

“…While they groomed for similar time, males groomed their bodies more frequently than females. Both genders groomed their A2 the most frequently, likely related to the role in sensory reception; cleaning of the A2 has been reported in other crustaceans (Bauer, 1989;Wortham and Pascual, 2017). The P1, as the main grooming appendage, has rarely been observed in crustaceans; shrimps used P2 as a main grooming appendage whereas two brachyurans used their P4 and P5 (Bauer, 1989;Wortham and Pascual, 2017).…”

“…Crabs were randomly selected after being collected (mean CW=22 mm; mean mass = 53 g); only one individual used had reached sexual maturity (based on CW) and had stopped molting (Rjiba-Bahri et al, 2019). Following procedures in Wortham and Pascual (2017), crabs had one grooming appendage removed; the 3M epipod has been documented to clean the ventral side of the gills in L. dubia (cf. Wortham and LaVelle, 2016) and was removed.…”

“…While most grooming research has focused on decapod shrimps, grooming behaviors have varied among crustacean groups such as shrimps, amphipods, and stomatopods (Bauer, 1977;1978;Felgenhauer and Schram, 1979;Holmquist, 1985;Wortham, 2011, 2014;Wortham and Kostecka, 2019). Detailed grooming behaviors of brachyurans have been reported in one study (Callinectes sapidus Rathbun, 1896 and Menippe mercenaria Say, 1818;Wortham and Pascual, 2017); differences existed in the grooming appendages, body regions groomed, fouling levels, and the grooming time budgets of these two crabs (5% vs 49%). Grooming has been unpredictable in crustaceans, even within one taxonomic group.…”

“…Mechanisms, morphological structures, and behaviors associated with grooming have differed greatly, but the function has remained the same (keep body regions free of fouling). Grooming behaviors in crustaceans have targeted different body regions: chemosensory antennules (Bauer, 1981;VanMaurik and Wortham, 2014), eyes (Wortham and Kostecka, 2019), gills (Wortham and Pascual, 2017), and jointed appendages (Hinsch, 1972;Videl-Gadea and Berlanger, 2009;Bauer, 2013). Bauer (1999) documented that grooming behaviors remove fouling; when grooming appendages were amputated in experiments, body fouling increased.…”

“…Many brachyuran crabs have been documented to undergo a terminal molt (Callinectes sapidus: Haefner and Shuster, 1964;Chionoecetes opilio Fabricius, 1788: Conan andComeau, 1986;majid crabs: Hines, 1989). Grooming and a terminal molt have not been linked before; only a few researchers have even mentioned grooming in brachyuran crabs (Walker, 1974;Bauer, 1981;Sallem et al, 2007), with one detailed study (Wortham and Pascual, 2017).…”