Female reproductive responses to photoperiod and male odours in the subterranean rodent Ctenomys talarum

FANJUL, MARÍA SOL; ZENUTO, ROXANA

ACTA THERIOLOGICA

Polish academy of sciences

Lugar: Bialowieza; Año: 2008 vol. 53 p. 73 - 85

0001-7051

The tuco-tuco Ctenomys talarum Thomas, 1898 is a sol i tary sub ter ra nean r o d e n t t h a t b r e e d s s e a s o n a l l y i n c o a s t a l s a n d - d u n e g r a s s l a n d s f r o m Ar gen tina. We as sessed whether short-day photoperiod de ter mines the on set of re pro duc tion by an in crease in fe male’s re cep tiv ity and whether male odour in ter acts with photoperiod as a cue by pro duc ing a greater re sponse in re cep tiv ity. Re cep tiv ity was mea sured by an in crease in the per cent age of vag i nal ep i the lial cells, par tic u larly cornified cells. Fe males were trapped dur ing their non-re pro duc tive season (sum mer-long days) and ran domly as signed to dif fer ent day-length ex per i men tal groups: con stant sum mer (CS), early win ter (EW), and nat u ral (NA) photoperiod. We exam ined the vag i nal ep i the lium us ing vag i nal smears dur ing the first ex per i men tal phase (120 days) to test the ef fect of photoperiod. In the sec ond ex per i men tal phase (15 days), we pre sented the fe males with male-soiled shav ings to test the ef fect of photoperiod and male odor. Ctenomys talarum fe males showed some ev i dence of re pro duc tive re spon sive ness to photoperiodic cu ing. The pro por tion of e p i t h e l i a l c e l l s pe a k e d e a r l i e r i n f e ma l e s wh e n wi nt e r d a y - l e ng t h wa s ad vanced than in fe males un der nat u ral photoper iod. Con t rary to that ex pected, male odours did not stim u late fe male re cep tiv ity. These re sults sug gest that, while photoperiod may par tic i pate in reg u lat ing re pro duc tion, the inte gra tion of other envi ron men tal and so cial fac tors, as well as the iden t i f i ca t ion of bodi ly con di t ions that lead to di f fer ences in in di vid ual re sponse needs fur ther con sid er ation. Key words: Ctenomys, sub ter ra nean ro dents, photoperiod, odours, vag i nal smears