Behaviors of the pelagic red crab Pleuroncodes planipes observed ...

Behaviors of Pleuroncodes planipes 69Fig. 1. Illustration of swimming bout by Pleuroncodes planipes: A) launch from bottom, B) tail-flipswimming, C) breach surface of water, D) sink, E) landing on side wall. Illustration by D. Tulipani.(Fig. 1A–C), 2) sinking (Fig. 1D), 3) surfaceswimming pattern (whereby the crab stays nearthe water’s surface to feed) (Fig. 2A), 4) hovering(crab maintains vertical position within thewater column by using several abbreviated tailflips)(Fig. 2B), 5) walking (Fig. 2D), and 6)climbing (Fig. 2C).Stationary behavior defined as the crabstanding relatively still on a surface was dividedinto three subcategories: 1) interactions withanother crab, included a) pushing, b) bumping,c) landing on (Fig. 2F), d) sparring (Fig. 2E),e) tail-flick, and f) antenna flick; 2) “groomingbehavior” was based on which body part wasbeing cleaned and usually entailed the scrubbing,rubbing, or wiping of these various bodyparts with one (or both) of the two modifiedfifth pereopods, wiping an eye with both maxillipeds,or by dragging an antenna between themaxillipeds; 3) “feeding behavior” was basedon the appendage by which food was capturedand transferred to the mouth region. The abovementionedsubcategories 2) and 3) had moredetailed components based only on the greatervariety of modes of collecting food and areas ofgrooming.Each occurrence of behaviors was tallied ona datasheet during the 15-minute observationtime for each crab. The tallies for each behaviorwere totaled and summarized. Terminology and