Biology subjects

Lima, S. M. Q.

Publications and source records attributed to Lima, S. M. Q..

3 recordsLinked to original sources

bioRxiv2021

Climate change shifts abiotic niche of temperate skates towards deeper zones in the Southwestern Atlantic Ocean

Climatic changes are disrupting distribution patterns of populations through shifts in species abiotic niches and habitat loss. The abiotic niche of marine benthic taxa such as skates, however, may be more climatically stable compared to upper layers of the water column, in which aquatic organisms are more exposed to immediate impacts of warming. Here, we estimate climate change impacts in Riorajini, a tribe of four skates, as a proxy to (1) evaluate the vulnerability of a temperate coastal zone in the Atlantic Southwest, and (2) study niche dynamics in a scenario of environmental changes on this group of threatened species. We modelled each species abiotic niche under present (2000-2014) and future (2100, Representative Concentration Pathway 8.5) climatic scenarios, then measured niche overlap, stability, expansion, and unfilling. Our results reveal an expansion of suitable environment for the occurrence of the tribe in up to 20% towards deeper areas (longitudinal shift), although still within the limits of the continental shelf. We discussed the downfalls of such shift to the species and to the local biota in newly invaded areas, and suggest that even deeper layers of marine temperate zones are vulnerable to dramatic environmental changes as a consequence of global warming.

ecology↗

bioRxiv2020

More than meets the eye: syntopic and morphologically similar mangrove killifish species show different mating systems and patterns of genetic structure along the Brazilian coast

Different mating systems can strongly affect the extent of genetic diversity and population structure among species. Given the increased effects of genetic drift on reduced population size, theory predicts that species undergoing self-fertilization should have greater population structure than outcrossed species, however demographic dynamics may affect this scenario. The mangrove killifish clade is composed of the two only known examples of self-fertilising species among vertebrates (Kryptolebias marmoratus and K. hermaphroditus). A third species in this clade, K. ocellatus, inhabits mangrove forests in southeast Brazil, however its mating system and patterns of genetic structure have been rarely explored. Here, we examined the genetic structure and phylogeographic patterns of K. ocellatus along its distribution, using mitochondrial DNA and microsatellites to compare its patterns of genetic structure with the predominantly selfing and often syntopic, K. hermaphroditus. Our results indicate that K. ocellatus reproduces mainly by outcrossing across much of its known range, with no current evidence of selfing, despite being an androdioecious species. Our results also reveal a stronger population subdivision in K. ocellatus compared to K. hermaphroditus, contrary to the theoretical predictions based on reproductive biology of the two species Our findings indicate that, although morphologically similar, K. ocellatus and K. hermaphroditus had remarkably different evolutionary histories when colonising the same mangrove areas in south-eastern Brazil, with other factors (e. g. time of colonisation, dispersal/establishment capacity) having more profound effects on the current population structuring of those species than differences in mating systems.

evolutionary biology↗

bioRxiv2019

Local parasite pressures and host genotype may modulate epigenetic diversity in a mixed-mating fish

Parasite-mediated selection is one of the main drivers of genetic variation in natural populations. The persistence of asexual reproduction and self-fertilization, however, challenges the notion that low genetic variation and inbreeding compromise the hosts ability to respond to pathogens. DNA methylation represents a potential mechanism for generating additional adaptive variation under low genetic diversity. We compared genetic diversity (microsatellites and AFLPs), variation in DNA methylation (MSAFLPs), and parasite loads in three populations of Kryptolebias hermaphroditus, a unique mixed-mating (partially self-fertilising) fish, to analyse the potential adaptive value of DNA methylation in relation to genetic diversity and parasite loads. We found strong genetic population structuring, as well as differences in parasite loads and methylation levels among sampling sites and selfing lineages. Globally, the interaction between parasites and inbreeding with selfing lineages influenced DNA methylation, but parasites seemed more important in determining methylation levels at the local scale.

zoology↗