“…Thus, clock gene transcript level oscillations need to be studied in relation to diurnal and seasonal light and temperature variations to elucidate the zeitgeber mechanisms in P. hirtus. Examples of behavorial or metabolic rhythmicity in subterranean species include blind mole rats, the cavefish genera Astyanax and Nemacheilus, myriapods and crustaceans (Cooper et al, 1993;De La O-Martinez et al, 2004;Erckens and Martin, 1982;Goldman et al, 1997;Jegla and Poulson, 1968;Koilraj et al, 2000;Kumar Pati, 2001) (for a review, see Lamprecht and Weber, 1992). Curiously, while our data represent the first demonstration of the expression of the complete circadian gene network in a troglobiont, no evidence of oscillating behavior or metabolic activities has so far been reported for P. hirtus.…”