How aerodynamic is a lobster?
Lobsters have a high Reynolds number, which means they can move a lot faster than something with a lower one. So, yes, they can be more aerodynamic than a Jeep Wrangler.
A lobster’s olfactory antennules have two branches, called flagella, which contain olfactory sensilla that connect to chemosensory neurons in the brain. When an odorant plume is encountered, the lobster can use instantaneous sensory feedback to guide movement toward the source. This information can come from the antennules themselves, or from olfactory receptor neurons in the brain that are a combination of antennule and leg chemosensing.
Our experiments tested whether spatial or temporal information could improve a lobster’s ability to locate the odorant source within an odorant plume generated by turbulent flow. We simulated the turbulent flow and odorant plume using computational fluid dynamics and verified its accuracy with physical flume studies. We then used different search algorithms that incorporated either antennule or leg chemosensing and olfactory data from an artificial neural network.
The concentration search algorithm used antennule chemosensing to determine search direction based on the time since the last odor encounter, while the intermittency search algorithm incorporated both antennule and leg chemosensing in order to decide movement based on the frequency of recent olfactory encounters. We found that both strategies proved to be effective in locating the odorant source. However, a search strategy that used both antennule and leg chemistry improved the results of both algorithms, which suggests that a combined approach is better than either antennule or leg chemosensory alone.
