Hammond R D, Fingerman M
Chronobiologia. 1975 Apr-Jun;2(2):119-32.
Locomotor activity rhythms in the crayfish, Faxonella clypeata, were recorded under conditions of controlled light and temperature. In LD 12:12, dark active rhythms with a major activity onset at lights-off, and bimodally active rhythms with onsets at both lights-on and lights-off were recorded. In DD, most of the LD dark active rhythms retained the lights-off activity onset. However, among the majority of the LD bimodally active crayfish, only the lights-on activity peak persisted in DD. A small number of the LD bimodal rhythms remained bimodal in DD. DD records revealed free-running period lengths both greater and less than 24 hrs. An hypothesis stating that the two recorded LD rhythms represent two basically different rhythmic types is presented. The dark active crayfish appear to entrain to the lights-off position, but the bimodally rhythmic crayfish appear to entrain to the lights-on position.
在可控的光照和温度条件下，记录了克氏原螯虾（Faxonella clypeata）的运动活动节律。在12小时光照：12小时黑暗（LD 12:12）条件下，记录到了主要在熄灯时开始活动的暗活动节律，以及在开灯和熄灯时都开始活动的双峰活动节律。在持续黑暗（DD）条件下，大多数在LD 12:12条件下的暗活动节律仍保持在熄灯时开始活动。然而，在大多数LD双峰活动的小龙虾中，只有开灯时的活动高峰在DD条件下持续存在。少数LD双峰节律在DD条件下仍保持双峰。DD记录显示自由运行周期长度既有大于24小时的，也有小于24小时的。本文提出了一个假说，即所记录的两种LD节律代表两种基本不同的节律类型。暗活动的小龙虾似乎被诱导到熄灯位置，但双峰节律的小龙虾似乎被诱导到开灯位置。
