How four sympatric lizard species reproduce in the Wet Chaco of subtropical region of Argentina

ORTIZ, MARTÍN; BORETTO, JORGELINA; IBARGÜENGOYTÍA, NORA R.

Hangzhou

Congreso; The 8th World Congress of Herpetology; 2016

Squamates exhibit a variety of reproductivestrategies within and between lineages that has been assigned to phylogeny,environment factors, or both. Herein, we studied the reproductive cycles offour sympatric South American lizards that inhabit the Wet Chaco of Argentina,the oviparous species Tropidurus catalanensis (Tropiduridae)and Kentropyx viridistriga (Teiidae),and the viviparous species Ophiodes intermedius(Diploglossidae) and Mabuya dorsivittata(Scincidae). The male gonads were removed and processed by histologicaltechniques. In females, we registered the presence and number of vitellogenic follicles,oviductal eggs/embryos, and corpora lutea. We found that the two oviparousspecies showed multiple clutches, but they strongly differ in theirreproductive cycles and activities. Tropidurus catalanensis malesshowed continuous spermatogenesis throughout the year, although the maximumgonadal activity occurs in spring; and females exhibited a seasonalreproductive cycle restricted to spring-summer. In contrast, Kentropyx viridistriga exhibited brumationduring winter and spring, and a synchronous reproductive activity between malesand females from early summer to autumn. The viviparous semifossorial Ophiodes intermedius exhibitedasynchronous reproductive cycles between sexes, with maximum spermatogenicactivity in autumn, and stores sperm in epididymis or deferens duct throughoutthe year. Females ovulatemacrolecithal oocytes in spring, and births occurredbetween late springs to early summer, after 3-4 months of gestation. Mabuya dorsivittata showed a seasonal,annual and associated male and female cycle. Female ovulate microlecithaloocytes in midsummer, and births occurred during the following spring to earlysummer, after 10-11 months of gestation. The maximum spermatogenic activity inmales was observed in late spring, coinciding with the beginning of the time ofbirth. We found different reproductive strategies between the four sympatricspecies studied, but their reproductive cycles are similar to theircounterparts in other regions, suggesting there is a strong phylogenetic componentthat would explain the reproductive phenotypes observed.