Presence of the tunicate on ship hulls and aquaculture facilities in the coast of the Biobío Region, south central Chile.

Non-native ascidians are important members of the fouling community associated with artificial substrata and man-made structures. Being efficient fouling species, they are easily spread by human-mediated transports (e.g.

The variable routes of rafting: stranding dynamics of floating bull kelp Durvillaea antarctica (Fucales, Phaeophyceae) on beaches in the SE Pacific.

Dispersal on floating seaweeds depends on availability, viability, and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°-42°S).

Species replacement along a linear coastal habitat: phylogeography and speciation in the red alga Mazzaella laminarioides along the south east Pacific.

Background: The Chilean shoreline, a nearly strait line of coast expanding across 35 latitudinal degrees, represents an interesting region to assess historical processes using phylogeographic analyses. Stretching along the temperate section of the East Pacific margin, the region is characterized by intense geologic activity and has experienced drastic geomorphological transformations linked to eustatic and isostatic changes during the Quaternary. In this study, we used two molecular markers to evaluate the existence of phylogeographic discontinuities and detect the genetic footprints of Pleistocene glaciations among Patagonian populations of Mazzaella laminarioides, a low-dispersal benthic intertidal red seaweed that inhabits along ~3,700 km of the Chilean coastal rocky shore.

Temperature effects on gametophyte life-history traits and geographic distribution of two cryptic kelp species.

A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors.

THE LESSONIA NIGRESCENS SPECIES COMPLEX (LAMINARIALES, PHAEOPHYCEAE) SHOWS STRICT PARAPATRY AND COMPLETE REPRODUCTIVE ISOLATION IN A SECONDARY CONTACT ZONE(1).

During secondary contact between phylogenetically closely related species (sibling species) having diverged in allopatry, the maintenance of species integrity depends on intrinsic and extrinsic reproductive barriers. In kelps (Phaeophyceae), the observations of hybrids in laboratory conditions suggest that reproductive isolation is incomplete. However, not all interspecific crosses are successful, and very few hybrids have been observed in nature, despite the co-occurrence of many kelp species in sympatry.

SEX RATIO VARIATION IN THE LESSONIA NIGRESCENS COMPLEX (LAMINARIALES, PHAEOPHYCEAE): EFFECT OF LATITUDE, TEMPERATURE, AND MARGINALITY(1).

Little is known about variation of sex ratio, the proportion of males to females, in natural populations of seaweed, though it is a major determinant of the mating system. The observation of sexual chromosomes in kelps suggested that sex is partly genetically determined. However, it is probably not purely genetic since the sex ratio can be modified by environmental factors such as salinity or temperature.

Phylogeographic analyses of the 30 degrees S south-east Pacific biogeographic transition zone establish the occurrence of a sharp genetic discontinuity in the kelp Lessonia nigrescens: vicariance or parapatry?

Phylogeographic studies are lacking in the Southern Hemisphere, and in particular in the south-eastern Pacific. To infer the possible scenario for the debated biogeographic transition zone located at 30-33 degrees S along the Chilean coast, we investigated whether there is a concordance between the phylogeographic pattern and the biogeographic transition in the intertidal kelp Lessonia nigrescens whose distribution is continuous across this transition zone. Using a combination of four makers located in the three genomic compartments (chloroplast, mitochondria and nucleus), we showed the presence of two main divergent lineages, possibly cryptic species.

Development and characterization of nine polymorphic microsatellite markers in the Chilean kelp Lessonia nigrescens.

A total of nine microsatellite loci were isolated and characterized in the Chilean kelp Lessonia nigrescens Bory. Using two different enriched libraries, we observed 1-14 alleles per locus in two samples of 21 kelp individuals each. The observed heterozygosities ranged from 0.