
Gonzalo GajardoUniversidad de Los Lagos · Biological Sciences and Biodiversity
Gonzalo Gajardo
PhD
About
129
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Introduction
Additional affiliations
March 1987 - December 2014
Laboratorio de Genética, Acuicultura & Biodiversity. Universidad de Los Lagos, Osorno
Position
- Principal Investigator
March 1986 - present
Publications
Publications (129)
Exotic salmonids were deliberately introduced to the Southern Hemisphere during the last part of the 20th century, initially to boost sport fishing and later to develop an aquaculture industry. Early introductions were justified by governments on purely utilitarian arguments as it was felt that translocated salmonids would capitalize on otherwise '...
The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological) to the population level. Such conditions are...
Chile is attracting a lot of attention lately as one of the most stable economies in South America, a low-risk country for investment, fully committed to the rules of the market, to economic growth, and to technological improvement. The country expects to be at the front door of development by 2010, on the occasion of the bi-centennial anniversary...
Local adaptations are important in evolution as they drive population divergence and preserve standing genetic diversity essential for resilience under climate change and human impacts. Protecting locally adapted populations is essential for aquaculture species. However, high larval connectivity and frequent translocations challenge this in Chilean...
The brine shrimp Artemia , a crustacean adapted to the extreme conditions of hypersaline environments, comprises nine regionally distributed sexual species scattered (island-like) over heterogeneous environments and asexual (parthenogenetic) lineages with different ploidies. Such sexual and asexual interaction within the genus raises questions rega...
Parthenogenesis is an asexual reproduction mode characterized by the development of a female oocyte without fertilization. From an evolutionary perspective, parthenogenesis seems less successful than the predominant sexual mode, though there are groups in which both reproductive types exist, an example of which is the genus Artemia Leach, 1819. Thi...
Species are fundamental units of nature that need proper identification in order to assess and conserve biodiversity. Artemia is a model crustacean for population analysis and comparison in regionally endemic sexual species and parthenogenetic lineages distributed in hypersaline lakes, lagoons, and solar saltworks scattered in arid and semi-arid ar...
Hypersaline lakes in arid and semi-arid areas are unique ecosystems that harbor unique extremophile organisms, such as Artemia, the paradigmatic example of adaptation to harsh living conditions. We assessed the mitogenomic biodiversity of Artemia species from the Tibetan Plateau, China, a remote and yet minimally disturbed ecosystem with a variety...
Determining molecular markers for parasites provides a useful tool for their identification, particularly for larval stages with few distinguishable diagnostic characters. Avian cestodes play a key role in the food webs and biodiversity of hypersaline wetlands, yet they remain understudied. Using naturally infected Artemia, we identified cestode la...
Epigenetic variation affects gene expression without altering the underlying DNA sequence of genes controlling ecologically relevant phenotypes through different mechanisms, one of which is long non-coding RNAs (lncRNAs). This study identified and evaluated the gene expression of lncRNAs in the gill and mantle tissues of Mytilus chilensis individua...
The blue mussel Mytilus chilensis is an endemic and key socioeconomic species inhabiting the southern coast of Chile. This bivalve species supports a booming aquaculture industry, which entirely relies on artificially collected seeds from natural beds that are translocated to diverse physical–chemical ocean farming conditions. Furthermore, mussel p...
Species of Artemia are regionally endemic branchiopod crustaceans composed of sexual species and parthenogenetic lineages, and represent an excellent model for studying adaptation and speciation to extreme and heterogeneous hypersaline environments. We tested hypotheses of whether populations from the Tibetan Plateau belong to A. tibetiana Abatzopo...
Ecosystems of inland saline waters play a significant role in the biosphere and human life. Various articles of this Special Issue are devoted to a wide range of issues of their study and management. This introductory article gives a general overview of the types of inland waters on the planet, as well as the features of their ecosystems, reflected...
Limited stocking efforts to introduce Atlantic salmon Salmo salar into Chilean rivers and streams were unsuccessful during the 20 th century. Following the arrival of the aquaculture industry during the 1980s, escaped Atlantic salmon have presented an ecological risk to native taxa through predation, competition, and transmission of pathogens or pa...
The blue mussel Mytilus chilensis is a key socioeconomic species inhabiting the southern coast of Chile. This endemic marine mussel supports a booming aquaculture industry, which entirely relies on artificially collected seeds from natural beds that are translocated to diverse physical-chemical ocean farming conditions. Furthermore, mussel producti...
Intraspecies nucleotide sequence variation is a key to understanding the evolutionary history of a species, such as the geographic distribution and population structure. To date, numerous phylogenetic and population genetics studies have been conducted based on the sequences of a gene or an intergenic region on the mitochondrial genome (mtDNA), suc...
We assessed the adaptive contribution of the mitochondrial genes involved with the respiratory chain and oxidative phosphorylation of the blue mussel Mytilus chilensis, a native and heavily exploited species in the inner sea of Chiloé Island, southern Chile. The assembled mitochondrial transcriptome of individuals from two ecologically different fa...
Harmful algae blooms (HABs) monitoring has been implemented worldwide, and Chile, a country famous for its fisheries and aquaculture, has intensively used microscopic and toxin analyses for decades for this purpose. Molecular biological methods, such as high-throughput DNA sequencing and bacterial assemblage-based approaches, are just beginning to...
A correction to this paper has been published: https://doi.org/10.1007/s10592-021-01376-9
Further biogeographical studies of parasites are vital to improve our understanding of biodiversity distribution and predict the impacts of global change. Hypersaline lakes are good laboratories to investigate the avian cestode abundance and species diversity given the abundance of hosts (waterbirds and Artemia) and their broad latitudinal distribu...
The study of adaptive population differences is relevant for evolutionary biology, as it evidences the power of selective local forces relative to gene flow in maintaining adaptive phenotypes and their underlying genetic determinants. However, human-mediated hybridization through habitat translocations, a common and recurrent aquaculture practice w...
The health of the world’s oceans are intrinsically linked to the biodiversity of the ecosystems they sustain. The importance of protecting and maintaining ocean biodiversity has been affirmed through the setting of the UN Sustainable Development Goal 14 to conserve and sustainably use the ocean for society’s continuing needs. The decade beginning 2...
Phytoplankton blooms, including harmful algal blooms (HABs), have serious impacts on ecosystems, public health, and productivity activities. Rapid detection and monitoring of marine microalgae are important in predicting and managing HABs. We developed a toolkit, the Suitcase Lab, to detect harmful algae species in the field. We demonstrated the Su...
Background
Vibrio species display variable and plastic fitness strategies to survive and interact with multiple hosts, including marine aquaculture species that are severely affected by pathogenic Vibrios. The culturable Vibrio sp. strain ArtGut-C1, the focus of this study, provides new evidence of such phenotypic plasticity as it accumulates polyh...
Harmful algae blooms (HABs) cause acute effects on marine ecosystems due to their production of endogenous toxins or their enormous biomass, leading to significant impacts on local economies and public health. Although HAB monitoring has been intensively performed at spatiotemporal scales in coastal areas of the world over the last decades, procedu...
The hypersaline lagoons located in evaporation basins or salars (salt flats) in the Atacama Desert are extreme environments harbouring a specialised biota able to survive harsh conditions for life. The knowledge of the parasitic biodiversity of these extreme habitats is still scarce despite their functional importance in regulating relevant non-eco...
Las comunidades costeras de pesca artesanal (conocidas a pequeña escala como “caletas”) son sistemas socioecológicos complejos que se adaptan a las perturbaciones dependiendo de su complejidad y propiedades inherentes. La capacidad de evaluar y monitorear esta respuesta adaptativa proporciona información sobre la sostenibilidad de las caletas, nece...
The brine shrimp genus Artemia Leach (Crustacea, Branchiopoda), a keystone group in hipersaline wetlands all over the world, offers an excellent model to study species interactions (parasitism) and to explore “hidden fauna” (avian endoparasites). The present study is the first report on the parasite infection of the South American species Artemia p...
Hypersaline lakes or brines are unique ecosystems with unique value and biodiversity that provide economic (mining) and noneconomic services (waterbird habitat). As they are shrinking around the world due to brine diversion and climatic oscillations, this article alerts on the fragility of Andean high‐altitude hypersaline lagoons in Salar de Atacam...
The brine shrimp Artemia is a highly required, convenient and cost‐effective live food used in fish and shellfish larviculture. Its cysts, originating from a limited number of inland salt lakes, are traded worldwide. Over the past decades, Artemia pond production in solar saltworks, integrated with salt production, has emerged as an alternative to...
The brine shrimp Artemia Leach (Crustacea, Branchiopoda), a keystone species in extremely saline wetlands all over the world, offers an excellent model to study species interactions (parasitism) and to elucidate “hidden fauna” (avian endoparasites). The present study is the first report on the parasite infection of the South American species Artemi...
The brine shrimp Artemia Leach (Crustacea, Branchiopoda), a keystone species in extremely saline wetlands all over the world, offers an excellent model to study species interactions (parasitism) and to elucidate “hidden fauna” (avian endoparasites). The present study is the first report on the parasite infection of the South American species Artemi...
This study presents preliminary evaluations for the potential use of Oil Bodies (OBs), spherical intracellular organelles that store lipids in the rapeseed Brassica napus, as a dietary supplement in aquaculture feeds. Objectives are straightforward: to evaluate OBs capacity to microencapsulate the highly valued but liable lipid-soluble pigment asta...
Different pathways of propagation and dispersal of non-native species into new environments may have contrasting demographic and genetic impacts on established populations. Repeated introductions of rainbow trout (Oncorhynchus mykiss) to Chile in South America, initially through stocking and later through aquaculture escapes, provide a unique setti...
Laguna de los Cisnes (53°15’S) is a remote and unusual salty lagoon located in the Chilean Patagonia, declared natural monument to protect bird diversity in the area, which could also serve as a natural laboratory to monitor climate change. This study reports basic water, sediment and plankton characteristics observed during a summer (December) sam...
Abstract The populations of Artemia (or brine shrimp) from the Americas exhibit a wide variation in the amount of interphase heterochromatin. There is interest in understanding how this variation affects different parameters, from the cellular to the organismal levels. This should help to clarify the ability of this organism to tolerate brine habit...
Previous researches have established that the swim speed of some microcrustaceans is influenced by chemical compounds emitted by conspecifics. We examined the hypothesis that cuticular compounds present on the body surface of A. franciscana, the most widespread member of Artemia genus, play a role in the swim speed of conspecific males. The movemen...
The palm ruff, Seriolella violacea (Cojinoba), is a potential new species for Chilean aquaculture. To approach Cojinoba larviculture, an experimental Artemia enrichment emulsion, containing docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) = 2.5, supplemented with vitamin E, astaxanthin, and β-glucan, was evaluated in both Artemia and Cojinoba...
Two behavioral experiments were performed to test that A. franciscana shows specific courtship patterns, which in part, would be governed by semiochemicals released by females. The courtship ethogram, based on 30 adult virgin pairs (1 female v/s 1 male) individually video recorded for 1 hour, revealed that males display four independent activity pa...
Knowledge about the genetic underpinnings of invasions-a theme addressed by invasion genetics as a discipline-is still scarce amid well documented ecological impacts of non-native species on ecosystems of Patagonia in South America. One of the most invasive species in Patagonia's freshwater systems and elsewhere is rainbow trout (Oncorhynchus mykis...
AimThe ecological effects of biological invasions are well documented, but little is known about the effects of invaders on the genetic structure of native species. We examined the phylogeography, genetic variation and population structuring of two galaxiid fishes, Aplochiton zebra and A. taeniatus, threatened by non-native salmonids, and whose con...
The brine shrimp Artemia (Crustacea) and a diversity of halophilic microorganisms coexist in natural brines, salterns and laboratory cultures; part of such environmental microbial diversity is represented in the gut of Artemia individuals. Bacterial diversity in these environments was assessed by 16S rRNA gene denaturing gradient gel electrophoresi...
Table S3. Results of bayescan and lositan programs for outlier detection in (a) brown trout and (b) rainbow trout.
Table S4. (a) Differentiation of brown trout populations expressed as (a) pairwise FST comparisons (below diagonal) and Dest (above diagonal) among Chilean and Falklands populations and (b) as pairwise FST estimated from neutral (below diagonal) and gene-linked (above diagonal) markers.
Table S5. Correlations between PST, FST, PST/FST and geographical distance.
Table S2. Summary genetic statistics for brown trout considering (a) global sample (over all populations) and (b) population-specific.
Figure S2. Relationship between observed (solid line) and neutral (dashed line) PST/FST, for four phenotypic traits of (a) brown trout and (b) rainbow trout.
Figure S1. Individual growth curves, represented as cumulative scale growth profiles (mm) at each growth circulus, among invasive brown trout (n: 5) and rainbow trout (n: 7) populations.
Table S1. Strains of rainbow trout and brown trout introduced in Chile and the Falkland Islands.
Invasion success may be expected to increase with residence time (i.e., time since first introduction) and secondary releases (i.e., those that follow the original introduction), but this has rarely been tested in natural fish populations. We compared genetic and phenotypic divergence in rainbow trout and brown trout in Chile and the Falkland Islan...
Biological invasions create complex eco-logical and societal issues worldwide. Most of the knowledge about invasions comes only from success-ful invaders, but less is known about which processes determine the differential success of invasions. In this review, we develop a framework to identify the main dimensions driving the success and failure of...
The relationship between invaders and the pathogens encountered in their new environment can have a large effect on invasion success. Invaders can become free from their natural pathogens and reallocate costly immune resources to growth and reproduction, thereby increasing invasion success. Release from enemies and relaxation of selective pressures...
The ability of invasive species to adapt to novel conditions depends on population size and environmental mismatch, but also on genetic variation. Away from their native range, invasive species confronted with novel selective pressures may display different levels of neutral versus functional genetic variation. However, the majority of invasion stu...
Biological invasions represent one of the greatest threats to aquatic ecosystems, particularly in locations a high degree of isolation and endemism, such as southern South America. In this region, salmonids are top-level invaders, but information about their dispersal, persistence, and population dynamics is still limited. Here, we used available h...
1. Direct ecological effects of biological invasions have been widely documented, but indirect genetic effects on native species are poorly known. In many cases, this is because of the lack of information on the genetic structure of species affected by invasions.
2. We used microsatellite DNA loci to estimate the genetic structure and gene flow pat...
The conservation of data deficient species is often hampered by inaccurate species delimitation. The galaxiid fishes Aplochiton zebra and Aplochiton taeniatus are endemic to Patagonia (and for A. zebra the Falkland Islands), where they are threatened by invasive salmonids. Conservation of Aplochiton is complicated because species identification is...
Hybrid assignments based on (a) simulated membership proportions of 100 multilocus genotypes per class using HYBRIDLAB and (b) results of admixture analysis using STRUCTURE: A. zebra parentals, A. taeniatus parentals, F1 hybrids, F2 hybrids and backcrosses. Results from the admixture analysis in STRUCTURE are for K = 2, averaged from 20 runs. Each...
Nucleotide sequence alignment of mitochondrial DNA of
Aplochiton zebra
(A) and
Aplochiton taeniatus
(B) according to (a)
COI
haplogroups and (b)
Cyt b
haplogroups.
(DOC)