2005 Fiscal Year Final Research Report Summary
Vision and behavior in crustacean decapods
| Project/Area Number |
15580162
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
General fisheries
|
|---|
| Research Institution | Mie University |
|---|
Principal Investigator |
KOIKE Takashi Mie University, Faculty of Bioresources, Professor, 生物資源学部, 教授 (60093126)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | Japanese spiny lobster / rock crab / ethology / light threshold / spectral sensitivity / direction of light / localization / directional sensitivity |
|---|
| Research Abstract |
Diurnal variation of moving activity of Japanese spiny lobsters and rock crabs were investigated in small indoor tanks. We modeled the diurnal of variation of light intensity with step-like brightness variation having 12L12D periods. The lobster and the crab movements were detected by measuring tension of wire which hang lobster and crab cage. When the brightness is higher than threshold value of the lobster and the crab, the activity variation of them occurs just in phase with the brightness variation. When the daytime brightness was changed to lower than the threshold value, the variation pattern was disturbed, and their activity was high even in daytime. The threshold value of the lobster was about 2.3 x 10^<-5> lx, and that of the rock crab was about 5.7 x 10^<-3> lx, respectively. We obtained spectral sensitivity for lobster by using this scheme, high sensibility was between 490-520nm with a sharp fall-off in sensibility in 590 nm.
Light environments, the spectral irradiance and turbidity of water in the habitat of crustacean decapods were measured in Ise Bay and its neighboring waters. The light at the wavelength 565 nm penetrated to the deepest in Ise Bay while that was at the wavelength 490 nm in its neighboring waters (the open coastal waters).
|
