Are there sex differences in the way fish learn about their environment?

Background/Question/Methods

Previous work has shown that the sex of an animal can influence how it learns to navigate around an environment. In mammals, females often show a preference for remembering the location of a resource based on the landmarks she encounters en route, whereas males tend to prefer more egocentric strategies that rely upon which direction to turn, or travel in a specific compass direction. To date, no studies have explored sex differences in the kinds of spatial cues fish use. Several evolutionary hypotheses that address how and why sex differences arise have been proposed; the hypothesis with the most support suggests that sex differences in spatial abilities arise when males have a larger home range than females - a situation that often arises in different species of fish. We investigated sex differences in spatial learning and exploration behavior in a tropical freshwater fish the Trinidadian guppy, Poecilia reticulata, where females maintain larger territories than males and the sexes are easily distinguished morphologically.  

Results/Conclusions

We evaluated home range size and exploratory behavior using a novel open field test. Female guppies more readily explored the novel environment than male conspecifics (F_1,6 = 4.62, P = 0.04). Females were also bolder in a novel environment and more frequently entered open areas (F_1,2 = 4.80, P = 0.04). To quantify spatial abilities, fish were trained to learn a route through a maze. Cues within the maze were then manipulated to determine what kinds of information the fish were using to find their way to a food patch.