تاثير دوره ي نوري بر رفتار جهت گيري و صدف گزيني خرچنگ منزوي (Diogenes avarus (Heller,1865 خليج فارس

The Effect of Photoperiod on the Orientation and Shell Selection Behavior of the Persian Gulf Hermit Crab, Diogenes avarus (Heller, 1865

در اين تحقيق رفتار جهت­ گيري و صدف­ گزيني خرچنگ ­هاي منزوي Diogenes avarus تحت تاثير رژيم هاي نوري مختلف (D18:L6، D12:L12 و D6:L18) مورد مطالعه قرار گرفت. رفتار سه گروه خرچنگ منزوي كه به مدت 48 ساعت در معرض دوره­ هاي نوري مختلف بودند بررسي گرديد. نتايج نشان داد كه نور بر رفتار جهت­ گيري و صدف­ گزيني خرچنگ منزوي D. avarus موثر است. بدين صورت كه نمونه­ ها در گروه كنترل داراي جهت ­گيري يكنواخت بودند (0/05P) . در تيمار­هاي رژيم نوري، اختلاف معني­ داري بين درصد جهت­ گيري و صدف­ گزيني به سمت هدف در رژيم نوري D18:L6و D12:L12 وجود نداشت (0/05P). نتايج نشان داد كه رفتار جهت­ گيري به سمت صدف و انتخاب آن در خرچنگ منزوي تحت تاثير دوره­ ي نوري است و زماني كه روشنايي كمتر است، خرچنگ به سمت صدف جهت­ گيري مي­ كند و آن را انتخاب مي ­كند.

The aim of this study was to investigate the orientation and shell selection behavior of hermit crab Diogenes avarus under different photoperiod situations (6L: 18D, 12L: 12D, 18L: 6D) after 48 hours. The results showed that the light affected the orientation and shell selection behavior of hermit crab Diogenes avarus. This means that the orientation of the control group were uniform (P >0.05), but their orientation in different lighting regimes compared with control, were non-uniform (P< 0.05). In light treatments, there was not a significant difference between the percentage of orientation towards the target in the light regime 12L: 12D and 6L: 18D (P>0.05). However, by increasing the time of lighting 18L: 6D, hermit crab orientation toward the target was significantly decreased (P<0.05). The results showed that orientation and shell selection behavior were influenced by the optic period, and when the light was less, the hermit crab was more active in orientation behavior and shell selection.