dpage@ulowell.cs.ulowell.edu (Dee Page) (01/14/87)
Hi, does anyone know anything about triggerfish? There is currently some research going on at the New England Aquarium concerning the spawning of triggerfish. They are observing the triggerfish in captivity and trying to notice any periodicity. They have come up with some theories, but are at a loss to explain them. It seems they are on a lunar cycle, but they don't know how the moon could be having any effect. No moonlight can enter, they were in the tank before their first spawning, and they feel that gravity cannot have a big enough effect due to the size of the tank. These are not my opinions, I have already told them mine. What I am wondering is: does anyone have any good references on triggerfish; lunar effects on spawning (my pet theory is the gravitational effect) of any fish, especially in captivity; and periodicity in fish in general and in captivity. They are also looking at the effects of the lighting cycle at the aquarium, temperature, and other variables. They also noticed a seasonal peak, but have not acquired enough data to begin hypothesizing. Thank you very much, Sincerely, Dee Page
dean@violet.berkeley.edu (Dean Pentcheff) (01/16/87)
In article <945@ulowell.cs.ulowell.edu> dpage@ulowell.UUCP (Dee Page) writes: >Hi, does anyone know anything about triggerfish? There is currently >some research going on at the New England Aquarium concerning the spawning >of triggerfish. They are observing the triggerfish in captivity and trying >to notice any periodicity. They have come up with some theories, but are >at a loss to explain them. It seems they are on a lunar cycle, but they >don't know how the moon could be having any effect.... The following comment is not precisely about triggerfish, but is a bit of cautionary information about discounting lunar effects in non-obvious cases. One of the most peculiar examples I know of surfaced recently in the research of Ken Lohmann and Dennis Willows (recently or soon-to-be reported in Science). They studied the (neurobiology of) the magnetic orientation response in Aplysia (sea slugs). Their first suspicion that something was bizarre was that they found the Aplysia orienting relative to a magnetic field, but results from replicate experiments were not consistent. Ken was sitting with the data late one night and had a hare-brained idea. Sure enough: Aplysia exhibits magnetotaxis only during half of the lunar cycle. During the other half, it fails to display it. These beasties live in fairly deep, turbid water, and are not noted for their keen eyesight, so visual tracking seems unlikely. They also exhibit the behavior in the (enclosed) lab. Where they're picking up the lunar cues is still (so I understand) mysterious. -Dean (dean@violet.berkeley.edu)