Crab State Variables

Crabs are individual objects that maintain a large number of state variables that change as the crab moves and interacts with its environment. These variables are grouped into classes which include general variables about the crab, reproductive variables, molting variables, metabolism variables, movement variables and life history information. We use italicized text when referring to one of these variables within the crab model.

• General Variables: when instantiated (hr), current mass (g), current CW (cm), time when dies due to factors not modeled (hr).

• Reproduction Variables: sex (male or female), number of eggs currently carrying, maximum number of eggs it can carry before it must spawn, and mating status (not mated, mated, accumulating eggs, preparing to spawn, finished spawning).

• Molting Variables: instar, molt flag (not molting, preparing to molt, molting), mass next molt triggered, total energy required to molt, total energy expended molting.

• Metabolic Variables: eating status (not eating, eating or foraging), current stomach fullness (Eqn A.42), stomach volume (cm$^3$) (Eqn A.37), average quality of food in stomach (Eqn A.43), mass of food feeding on (g), quality of food feeding on.

• Movement Variables: Current location (x, y), current direction $\theta \in [0, 2\pi)$, rate of movement $v$ (m/hr), time of last update, interaction flag (do nothing, flee, hit estuary boundary), pointer to triangle crab was on at the time of last update, the time and the crab which the given crab interacts with next.