Field and laboratory experiments on the seasonal variation of the locomotor activity patterns in the desert terrestrial isopod Hemilepistus reaumurii

ABSTRACT

The locomotor activity pattern of the desert woodlouse Hemilepistus reaumurii was monitored over the four seasons in nature and in the laboratory.

Results showed that the activity of this species was mostly concentrated during the day in nature as well as under controlled laboratory conditions. Moreover, two main peaks around sunrise and sunset described this activity; this bimodality was clearer in summer and fall than in winter and spring.

Under controlled environmental conditions, the results indicated that individuals exhibited an endogenous rhythm of the locomotor activity with an astronomic and circadian 24 h period. The most clearly defined rhythm was found during the transition seasons in spring and fall whatever the imposed regimen.

KEYWORDS:

• Surface activity
• locomotor rhythm
• entraining conditions
• arid environment

Acknowledgments

We wish to thank Mrs. Sabiha KHIARI-AYARI, Ms. Nada AYARI and Ms. Nabiha AYARI for their important contribution in accomplishing the field work of this study.

Disclosure statement

No potential conflict of interest was reported by the authors.

Complying with ethics of experimentation

Ethical approval

The present study did not involve human participants.

All the applicable institutional guidelines for welfare, care and use of animals were followed.

Additional information

Funding

The present study was supported by the Research Laboratory of Diversity, Management and Conservation of Biological Systems: [Grant Number LR18ES06] and Faculty of Science of Tunis, University of Tunis El Manar.