Above: A subordinate N. pulcher
Below: Several N. pulcher hanging out around their shelter
Today we finally got to see some of the fish the majority of our experiments are focused on. Many of us agreed that its especially exciting to see these fish since we’ve spent so much time watching them in the lab.
Neolamprologus pulcher is a cooperatively breeding cichlid; that means their basic social system consists of a dominant breeding pair and a number of subordinate “helpers.” These helpers assist the breeding pair in defending against predators, raising their offspring, and maintaining the territory. These fish have been of interest to biologists for many years because the apparent altruistic behavior of the helpers doesn’t make evolutionary sense at first glance. Why help another fish (who they might not even be related to) at your own expense? Any helper that cheated would be at a huge advantage and you’d expect the cooperative system to fall apart. But it doesn’t.
These fish have very diverse and amusing behaviors. There is a dominance heirarchy within groups, and smaller individuals are submissive to the larger, more-dominant fish. One of these behaviors is called the “tail-quiver,” which as the name implies, involves the subordinate fish quivering its tail in front of the dominant fish.
I’m sure I’ll have plenty of stories of the antics of these fish, but for now just know that there are seven North Americans somewhere in Zambia who are very happy to have finally seen them in their natural habitat!
For more info on N. pulcher and some of the experiments I’m planning, check out this video from the SciFund Challenge a while back: http://www.youtube.com/watch?v=zmlZf6vnrQw