Publications

effects of the subterranean herbivorous rodent spalacopus cyanus on herbaceous vegetation in arid coastal chile.	the impact of the subterranean herbivorous rodent spalacopus cyanus molina on the herbaceous vegetation was studied by comparing biomass, species richness and species diversity at the end of the growing season in areas with and without burrows in coastal arid chile. total biomass was 60% higher in areas with burrows. this difference was mainly due to the large increase of mesembryanthemum cristallinum l., a succulent prostrate annual herb. unexpectedly, bulb biomass of geophytes, eaten by spalac ...	1991	28313359
microsatellites from the south american coruro, spalacopus cyanus.		2000	10972791
when nonshivering thermogenesis equals maximum metabolic rate: thermal acclimation and phenotypic plasticity of fossorial spalacopus cyanus (rodentia).	many small mammals inhabiting fluctuating and cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (nst) and thermoregulatory maximum metabolic rate (mmr). however, it is not known how this plasticity remains in a mammal that rarely experiences extreme thermal fluctuations. in order to answer this question, we determined body mass (m(b)), basal metabolic rate (bmr), nst, mmr, and minimum thermal conductance (c) on a chilean fossorial caviomorph (spalacop ...	2001	11331504
gametogenesis and nucleotypic effects in the tetraploid red vizcacha rat, tympanoctomys barrerae (rodentia, octodontidae).	nucleotypic effects link dna content with nuclear size and cell dimensions of reproductive cells in polyploid organisms. we studied the gametogenesis of the allotetraploid rodent tympanoctomys barrerae, aiming to determine these effects in reproductive cells. the species' cofamily members, octodon degus and spalacopus cyanus were used as control. spermatogenesis and oogenesis in t. barrerae follows the pattern of differentiation and sequence of events of the control species, but varied nucleotyp ...	2004	15586825
hearing in coruros (spalacopus cyanus): special audiogram features of a subterranean rodent.	learning curves and behavioural audiograms of subterranean, socially living coruros (spalacopus cyanus) were obtained using a positive reinforcement conditioning procedure. the individually varying audiograms revealed best hearing at frequencies between 1.25 and 1.6 khz, which corresponds with the common pattern established in subterranean rodents studied so far. however, the broad hearing range covering frequencies at least between 0.25 and 20 khz coupled with the high sensitivity (average mini ...	2004	15322848
eye and vision in the subterranean rodent cururo (spalacopus cyanus, octodontidae).	subterranean mammals are generally considered to have reduced eyes and apparent blindness as a convergent adaptation to their lightless microhabitat. however, there are substantial interspecific differences. we have studied the prospect of vision in the chilean subterranean rodent cururo (spalacopus cyanus, octodontidae) by analyzing the optical properties of the eye, the presence and distribution of rod and cone photoreceptors, and their spectral sensitivities. cururo eye size is normal for rod ...	2005	15844175
a test of the thermal-stress and the cost-of-burrowing hypotheses among populations of the subterranean rodent spalacopus cyanus.	subterranean mammals show lower than-allometrically expected-basal metabolic rates (bmr), and several competing hypotheses were suggested to explain how physical microenvironmental conditions and underground life affect subterranean mammalian energetics. two of these are the thermal-stress and the cost-of-burrowing hypotheses. the thermal-stress hypothesis posits that a lower mass-independent bmr reduces overheating in burrows where convective and evaporative heat loss is low, whereas the cost-o ...	2005	15792598
circadian chronotypes among wild-captured west andean octodontids.	rest activity pattern was studied in wild-captured males of octodon degus (n=9), octodon bridgesi (n=3), and spalacopus cyanus (n=6) (rodentia: octodontidae). ten-minute resolution actograms were constructed from data obtained by an automated acquisition system. after two months of habituation to a stable light-dark schedule, recordings were performed in isolation chambers under a 12: 12 light dark schedule. a free-running period (constant darkness) was recorded for o. bridgesi and s. cyanus. o. ...	2006	16874396
acoustic communication and burrow acoustics are reflected in the ear morphology of the coruro (spalacopus cyanus, octodontidae), a social fossorial rodent.	we studied the middle and inner ears of seven adult coruros (spalacopus cyanus), subterranean and social rodents from central chile, using free-hand dissection and routine staining techniques. middle ear parameters that were focused on here (enlarged bullae and eardrums, ossicles of the "freely mobile type") are believed to enhance hearing sensitivity at lower frequencies. the organ of corti was of a common mammalian type and revealed three peaks of higher inner hair cell densities. based on a p ...	2006	16400643
comparative respiratory strategies of subterranean and fossorial octodontid rodents to cope with hypoxic and hypercapnic atmospheres.	subterranean rodents construct large and complex burrows and spend most of their lives underground, while fossorial species construct simpler burrows and are more active above ground. an important constraint faced by subterranean mammals is the chronic hypoxia and hypercapnia of the burrow atmosphere. the traits, regarded as "adaptations of rodents to hypoxia and hypercapnia", have been evaluated in only a few subterranean species. in addition, well-studied subterranean taxa are very divergent t ...	2010	20352232
searching for major urinary proteins (mups) as chemosignals in urine of subterranean rodents.	chemosensory information mediates behavior in many rodent genera. major urinary proteins (mups) facilitate chemical communication in some species of mice. we sought to demonstrate the importance of mups in chemosignaling across a range of rodent genera that live in different habitats and social structures. we analyzed urine from three subterranean rodent genera from different continents, and with diverse social systems: eusocial zambian mole-rats (fukomys), solitary israeli blind mole rats (spal ...	2011	21647723
the evolution of mitochondrial genomes in subterranean caviomorph rodents: adaptation against a background of purifying selection.	south american tuco-tucos (ctenomys) and the related coruro (spalacopus) are two rodent lineages that have independently colonised the subterranean niche. the energetically demanding lifestyles of these species, coupled with the hypoxic atmospheres characteristic of subterranean environments, may have altered the selective regimes on genes encoding proteins related to cellular respiration. here, we examined the molecular evolution of 13 protein-coding genes in the mitochondrial genome of seven c ...	2011	21723951
scaling and adaptations of incisors and cheek teeth in caviomorph rodents (rodentia, hystricognathi).	the south american hystricognath rodents are one of the most diverse mammalian clades considering their occupied habitats, locomotor modes and body sizes. this might have been partly evolved by diversification of their masticatory apparatus' structure and its ecological commitment, for example, chisel-tooth digging. in this phylogeny-based comparative study, we test the relationship between ecological behavior and mechanical features of their incisors and molariforms. in 33 species of nine famil ...	2012	22730038
two mitochondrial genes under episodic positive selection in subterranean octodontoid rodents.	tuco-tucos (ctenomys) and related coruros (spalacopus) are south american subterranean rodents. an energetically demanding lifestyle within the hypoxic, underground atmosphere may change the selective regime on oxidative phosphorylation. we examined whether weak and/or episodic positive directional selection affected the evolution of two mitochondrial genes (cox2, cytb), in a background of purifying selection in these lineages. we estimated rates of synonymous (ds) and non-synonymous (dn) substi ...	2014	24113079
selective binocular vision loss in two subterranean caviomorph rodents: spalacopus cyanus and ctenomys talarum.	to what extent can the mammalian visual system be shaped by visual behavior? here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, spalacopus cyanus and ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. s. cya ...	2017	28150809
molecular adaptive convergence in the α-globin gene in subterranean octodontid rodents.	tuco-tucos (ctenomys) and related coruros (spalacopus) are south american subterranean rodents. an energetically demanding lifestyle within the hypoxic/hypercapnic underground atmosphere may change the selective regime on genes involved in o2 transport in blood. in addition, some species of tuco-tucos may be found at high altitude, thus facing additional reductions in changes o2 availabily. we examined sequence variation in the alpha globin subunit gene of hemoglobine in these lineages, within a ...	2017	28735726
disturbance by an endemic rodent in an arid shrubland is a habitat filter: effects on plant invasion and taxonomical, functional and phylogenetic community structure.	disturbance often drives plant invasion and may modify community assembly. however, little is known about how these modifications of community patterns occur in terms of taxonomic, functional and phylogenetic structure. this study evaluated in an arid shrubland the influence of disturbance by an endemic rodent on community functional divergence and phylogenetic structure as well as on plant invasion. it was expected that disturbance would operate as a habitat filter favouring exotic species with ...	2017	28087661
changes in selection intensity on the mitogenome of subterranean and fossorial rodents respective to aboveground species.	several rodent lineages independently acquired the ability to dig complex networks of tunnels where fossorial and subterranean species spend part or their whole life, respectively. their underground lifestyles imposed harsh physiological demands, presumably triggering strong selective pressures on genes involved in energy metabolism like those coding for mitochondrial proteins. moreover, underground lifestyles must have increased inbreeding and susceptibility to population bottlenecks as well as ...	2018	29777385