Aggressiveness and life underground: the case of burrowing crayfish

Assessing the importance of burrows through behavioral observations of Parastacus brasiliensis, a Neotropical burrowing crayfish (Crustacea), in laboratory conditions

“…When exploring the area outside the burrow (9.1% of all behaviors), a crayfish would walk through the aquarium with its chelipeds held parallel to the substrate, occasionally touching it, and with very rapid movements of the antennae. This, along with the nocturnal activity and the small-sized eyes of this species (Buckup and Rossi 1980;Dalosto and Santos 2011;Dalosto et al 2013) compared to other species such as the stream-dwelling South American parastacid Samastacus spinifrons (Philippi, 1882) (Rudolph 2002), indicate that tactile orientation probably is highly important for P. brasiliensis. Our results also support statements by several investigators that P. brasiliensis is nocturnal (Dalosto and Santos 2011;Dalosto et al 2013), remaining in its burrow during the day and emerging at night to forage (Buckup , 2003.…”

“…It also must be noted that these classification systems for crayfish burrowing habits (Hobbs 1942) and burrows (Horwitz and Richardson 1986) were designed specifically for North American and Australian faunas. The South American crayfish fauna possesses a disproportionately high prevalence of burrowers, and investigations of their ecology can update and refine these classification systems so that we can analyze crayfish ecology within the same framework, including burrowing crayfish from all radiations (Morrone and Lopretto 1994;Taylor 2002;Collins et al 2011;Dalosto and Santos 2011;Dalosto et al 2012Dalosto et al , 2013. Given this, it is important that the habits and basic biology of the Neotropical fauna be studied, since they remain largely unknown.…”

“…The environmental pressures faced by burrowing crayfish strongly favor coexistence and overlapping generations. Evidence supporting this assumption includes gregarious tendencies (Punzalan et al 2001), low aggressiveness (Guiaşu et al 2005, Dalosto et al 2013, and prolonged parental care (Dalosto et al 2012). However, even though burrowing species behave differently from other crayfish, very little is actually known about them mainly because their fossorial habits make sampling difficult (Punzalan et al 2001;Richardson 2007).…”

“…Additionally, crayfish are widely used as behavioral models (Guiaşu and Dunham 1998;Gherardi 2002;Moore 2007), but this suggests the erroneous conclusion that the behavior of all crayfish is already known, leading researchers to ignore particular traits of a given species (Lundberg 2004). This is especially of concern given that burrowing crayfish are highly specialized animals, as clearly reflected in their behavior (Dalosto et al 2012(Dalosto et al , 2013. One useful tool that may help better understand the species' behavior is the ethogram (Altmann 1974;Lundberg 2004), especially when applied to animals with more specialized habits, such as Parastacus.…”

How to deal with a bad neighbor? Strategies of sympatric freshwater decapods (Crustacea) for coexistence

“…Some studies have suggested that aeglids are competitively superior to Neotropical crayfish, and have forced them out of optimal habitats (Riek, 1971;Dalosto & Santos, 2011;Palaoro et al, 2013b), which would result in one or more forms of segregation in natural environments. Given that aeglids are aggressive animals that occur in high densities, conversely to that which is known for Parastacus (Bueno & Bond-Buckup, 2000;Buckup, 2003, Ayres-Peres et al, 2011bDalosto et al, 2013), one would expect them to exhibit some form of segregation when they occur in sympatry. However, this hypothesis has not been investigated to date.…”