Browsing by Author "Ibanez, Christian M."

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    An updated biogeographic evaluation of endemism and conservation of small mammals from Chile
    (2023) Hernandez-Mazariegos, Wendy C.; Ibanez, Christian M.; Palma, R. Eduardo
    Ecological factors such as temperature, precipitation, and vegetation type have been reported to influence biogeographic patterns (e.g., species distribution, richness, and endemism) in mammals. In Chile, these patterns only had been explored in selected mammal groups from certain localities. In this study, we describe and analyze biogeographic patterns for all small mammals (marsupials, armadillos, bats, rodents), reported until 2020, in different climatic and ecological regions from continental Chile. Using a compiled database of 89 species, we estimated their distributional similarity, described and characterized richness and areas of endemism using Bayesian and Parsimony Analysis of Endemism, and linked species distribution with conservation status according to the IUCN Red List. We found three similarity units of species distribution based on climate: Arid, Temperate, and Polar; higher richness and endemism in north and south-central Chile; two areas of endemism, one in north and one in south; and a hotspot in south-central Chile. Finally, species of greater conservation concern showed a similar and small distribution range. The concordance in the distribution of the species with Chilean climatic regions (as determined by precipitation and temperature) suggest that the spatial distribution of Chilean small mammals is influenced strongly by those abiotic factors. This also could explain the patterns of richness and endemism and, therefore species hotspots. Variations of climatic factors therefore should be considered in explaining biogeographic patterns and conservation plans of Chilean small mammal species, because species of greater concern tend to be associated and having similar distributional characteristics.
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    Behavioral and chromatic dynamics describing mating interactions of the south American octopus Robsonella fontaniana (Cephalopoda: Octopodidae)
    (2023) Cifuentes, Victor; Perez-Matus, Alejandro; Fernandez, Miriam; Ibanez, Christian M.; Carrasco, Sergio A.
    Cephalopods are characterized by a substantial behavioral flexibility during reproductive interactions; however, for octopods rather few studies have provided empirical information on the mechanisms operating during male-male and male-female encounters. Using the small south American octopus Robsonella fontaniana (similar to 270 mm total length, similar to 70 mm mantle length), we evaluated the mating behavior based on octopuses from central Chile. Eighteen male-female and five male-male interactions were characterized in laboratory using ethograms divided into precopulatory and copulatory stages. Although subjects' interactions occurred in both treatments, extended mating periods (81-196 min) were only observed in the male-female trials, and specifically, in those involving larger octopuses (39% of the interactions; > 43 mm mantle length). During the precopulatory stage (4-20 min), different behavioral displays were evidenced in 57% of these male-female interactions, including: contact, exhibition of chromatic displays, swimming, and mounting. Larger pairs had longer copulation times, with a maximum of similar to 200 min in octopuses of 50 mm mantle length. The observed mating in adult male-female pairs and the practically null interaction between juveniles suggest that a maturity-conditional reproductive behavior (similar to 43 mm mantle length; similar to 38 gr), could be one of the mechanisms modulating mating interactions of R. fontaniana in the wild, potentially influencing aspects such as mate guarding behavior, possible sperm removal or sperm loading. (c) 2023 Elsevier B.V. All rights reserved.
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    Thorson's rule, life-history evolution, and diversification of benthic octopuses (Cephalopoda: Octopodoidea)
    (2018) Ibanez, Christian M.; Rezende Landaeta, Enrico; Sepulveda, Roger D.; Avaria-Llautureo, Jorge; Hernandez, Cristian E.; Sellanes, Javier; Poulin, Elie; Cecilia Pardo-Gandarillas, M.