scholarly journals The Hyalella species flock of Lake Titicaca (Crustacea: Amphipoda): perspectives and drawbacks of dna-based identification

2021 ◽  
pp. 1-54
Author(s):  
Damià Jaume ◽  
Francesco Zapelloni ◽  
Joan Pons ◽  
Carlos Juan ◽  
José A. Jurado-Rivera

Abstract Lake Titicaca, in the High Andes of Perú and Bolivia, harbours the world’s third most speciose ancient-lake amphipod radiation on record. A minimum of nineteen species of Hyalella derived from at least five independent colonization episodes concentrate in this high altitude water body, although the actual species number present has not yet been established and could be much higher. Herein, we take advantage of the description of three new species (H. krolli, H. gonzalezi, and H. hirsuta) and the re-description of other two (H. solida and H. nefrens) to assess the feasibility of adopting a dna-based identification approach to resolve the magnitude of this highly speciose amphipod assemblage. A Bayesian phylogenetic analysis of the evolutionary relationships among South American Hyalella cox1 haplotypes, including those of four out of the five species dealt with herein, shows a great disagreement between taxonomic units delimited under morphological and genetic data, hampering species identification exclusively based on cox1 dna barcode sequences.

2020 ◽  
Vol 89 (4) ◽  
pp. 353-372
Author(s):  
José A. Jurado-Rivera ◽  
Francesco Zapelloni ◽  
Joan Pons ◽  
Carlos Juan ◽  
Damià Jaume

The Hyalella species diversity in the high-altitude water bodies of the Andean Altiplano is addressed using mitochondrial cox1 sequences and implementing different molecular species delimitation criteria. We have recorded the presence of five major genetic lineages in the Altiplano, of which one seems to be exclusive to Lake Titicaca and nearby areas, whereas the rest occur also in other regions of South America. Eleven out of 36 South American entities diagnosed by molecular delimitation criteria in our study are likely endemic to the Titicaca and neighbouring water bodies. We have detected a remarkable disagreement between morphology and genetic data in the Titicacan Hyalella, with occurrence of several cases of the same morpho-species corresponding to several Molecular Operational Taxonomic Units (MOTUs), some even distantly related, and other instances where a particular MOTU is shared by a morphologically heterogeneous array of species, including species with body smooth and others with body heavily armoured. Species diversification and incongruence between morphological and molecular boundaries within this species assemblage may be associated to the sharp changes in hydrological conditions experienced by the water bodies of the Altiplano in the past, which included dramatic fluctuations in water level and salinity of Lake Titicaca. Such environmental shifts could have triggered rapid morphological changes and ecological differentiation within the Hyalella assemblage, followed by phenotypic convergence among the diverse lineages. Factors such as phenotypic plasticity, incomplete lineage sorting or admixture between divergent lineages might lie also at the root of the morphological-genetic incongruence described herein.


Phytotaxa ◽  
2017 ◽  
Vol 316 (2) ◽  
pp. 149 ◽  
Author(s):  
PEDRO LUÍS RODRIGUES DE MORAES ◽  
MATHEUS CARVALHO VERGNE ◽  
HENK VAN DER WERFF

Three South-American new species belonging to Cinnamomum, Mezilaurus, and Williamodendron, are described and illustrated from specimens collected in the Atlantic rainforest of Brazil. The new species are Cinnamomum baitelloanum, Mezilaurus sessiliflora, and Williamodendron itamarajuensis. Their putative relationships within the respective genus are discussed.


2010 ◽  
Vol 7 (11) ◽  
pp. 3387-3402 ◽  
Author(s):  
S. Trajanovski ◽  
C. Albrecht ◽  
K. Schreiber ◽  
R. Schultheiß ◽  
T. Stadler ◽  
...  

Abstract. Ancient Lake Ohrid on the Balkan Peninsula is considered to be the oldest ancient lake in Europe with a suggested Plio-/Pleistocene age. Its exact geological age, however, remains unknown. Therefore, molecular clock data of Lake Ohrid biota may serve as an independent constraint of available geological data, and may thus help to refine age estimates. Such evolutionary data may also help unravel potential biotic and abiotic factors that promote speciation events. Here, mitochondrial sequencing data of one of the largest groups of endemic taxa in the Ohrid watershed, the leech genus Dina, is used to test whether it represents an ancient lake species flock, to study the role of potential horizontal and vertical barriers in the watershed for evolutionary events, to estimate the onset of diversification in this group based on molecular clock analyses, and to compare this data with data from other endemic species for providing an approximate time frame for the origin of Lake Ohrid. Based on the criteria speciosity, monophyly and endemicity, it can be concluded that Dina spp. from the Ohrid watershed, indeed, represents an ancient lake species flock. Lineage sorting of its species, however, does not seem to be complete and/or hybridization may occur. Analyses of population structures of Dina spp. in the Ohrid watershed indicate a horizontal zonation of haplotypes from spring and lake populations, corroborating the role of lake-side springs, particularly the southern feeder springs, for evolutionary processes in endemic Ohrid taxa. Vertical differentiation of lake taxa, however, appears to be limited, though differences between populations from the littoral and the profundal are apparent. Molecular clock analyses indicate that the most recent common ancestor of extant species of this flock is approximately 1.99 ± 0.83 million years (Ma) old, whereas the split of the Ohrid Dina flock from a potential sister taxon outside the lake is estimated at 8.30 ± 3.60 Ma. Comparisons with other groups of endemic Ohrid species indicated that in all cases, diversification within the watershed started ≤2 Ma ago. Thus, this estimate may provide information on a minimum age for the origin of Lake Ohrid. Maximum ages are less consistent and generally less reliable. But cautiously, a maximum age of 3 Ma is suggested. Interestingly, this time frame of approximately 2–3 Ma ago for the origin of Lake Ohrid, generated based on genetic data, well fits the time frame most often used in the literature by geologists.


2021 ◽  
Vol 4 ◽  
Author(s):  
Anna Wysocka ◽  
Michal Grabowski ◽  
Lidia Sworobowicz ◽  
Sasho Trajanovski ◽  
Tomasz Mamos

Lake Ohrid, located on the Balkan Peninsula at the Albanian-Macedonian border, is the oldest European lake (1.3-1.9 My old) and one of the world’s smallest ancient lakes. Taking into account the size of the lake and its biodiversity, it harbors the highest level of endemism, especially within amphipod crustaceans (ca. 90%) with the endemic Gammarus species flock. Our previous studies upon this flock have shown a substantial decoupling between molecular and morphological diversity, existence of cryptic species and puzzling speciation history. In order to explore sources of observed diversity, in the current study we are investigating ecological preferences of the species within the flock, based on their distribution in depth gradient, in relation to molecular diversity based on DNA barcoding. In the study over 200 barcodes were generated and combined with 173 previously published. The specimens were collected from all depth ranges of Lake Ohrid as well as from springs located on or near the banks of the lake. Within the species flock, 13 BIN’s were identified, 12 previously known and one newly recognized, representing separate lineage and putatively a new species. Two of the flock species were found only in the springs: G. sketi and G. cryptosalemaai. G. sketi, previously found only in springs on the southern banks of Lake Ohrid, has now also been discovered in springs in its north-eastern part. Both species show low haplotypic diversity. All remaining species were recorded from the depth between 20 and 60 meters, that is characterized by the highest ecological diversity with different types of substrates: stones, macrophytes, abundant Dreissena shells as well as sand and silt. Among them G. sywulai, G. macedonicus, G. cryptoparechiniformis, G. lychnidensis, G. ochridensis, G. parechinifromis were found exclusively within this depth range. The three latter species represent single BIN and share haplotypes, at the same time this BIN has the highest number of haplotypes in comparison to others. The remaining species found on this depth represent separate BINs with different levels of haplotype diversity. Only G. lychnidensis, G. stankokaramani and G. solidus were found below the depth of 60 meters, in a quite homogenous environment dominated by silt. In the deepest parts of the lake, between 260 and 290 meters, only G. solidus was found. This species is represented only by three haplotypes while G. stankokaramani is characterized by multiple haplotypes partially shared with G. lychnidensis. The shared haplotype represents the only G. lychnidensis occurrences on the depths below 60 meters. Summarizing, the highest abundance of BINs, species and haplotypes was recovered from the most ecologically diversified depth range of the lake (20 to 60 meters). This suggests that ecological heterogeneity could be the main driver of Gammarus species flock diversification in the ancient Lake Ohrid. Due to the complex pattern of morphological diversity, DNA barcoding proved to be the best if not the only method in identification of the species flock diversity.


2021 ◽  
Author(s):  
◽  
Sergio Diaz Martinez

<p>Understanding speciation is one of the great challenges in evolutionary biology as many of the processes involved in speciation, as well as the forces leading to morphological and genetic differentiation, are not fully understood. Three main modes of speciation have been described: allopatric, parapatric and sympatric. Sympatric speciation is the most enigmatic mode because in the absence of physical barriers, disruptive selection, assortative mating and hybridization play central roles in reproductive isolation. Although it is accepted that sympatric speciation is possible, only a few examples of this process exist to date. Another common method of speciation in plants and algae is via polyploidization. Recently, a promising system to study speciation in sympatry was discovered: the endemic Cladophorales species flock in ancient Lake Baikal, Russia. The flock consists of sixteen taxa grouped in four genera: Chaetocladiella, Chaetomorpha, Cladophora and Gemmiphora. In spite of their morphological diversity, recent molecular analyses have shown that this is a monophyletic group with low genetic variation and nested within the morphologically simple genus Rhizoclonium. Due to their high number of species, endemism and sympatric distribution, many interesting questions have arisen such as what processes are involved in speciation, and whether this group might be a novel example of sympatric speciation. In this study, we analysed the population genetics of the endemic Baikalian Cladophorales to infer the processes shaping the evolution of the group. First, a set of microsatellites was designed using high-throughput sequencing data. Second, species delimitation methods based on genetic clustering were performed. Third, the population genetics of three widely distributed species was analysed looking for evidence of panmixia, a common criteria to support sympatric speciation. A total of 11 microsatellites that mostly cross-amplify between most species were obtained. The genotyping revealed that most loci had more than two alleles per individual indicating polyploidy. As such, the analyses required a different approach which consisted in coding the genotypes as ‘allelic phenotypes’, allowing the use of individuals of different ploidy levels in the same data set. The species delimitation of 15 operative morphotaxa and 727 individuals supported reproductive isolation of five morphotaxa and two hypotheses of conspecificity. However, some morphotaxa showed unclear assignments revealing the need of further research to clarify their reproductive limits. Finally, the population genetics of Chaetomorpha moniliformis, Cladophora compacta and Cl. kursanovii revealed patterns of genetic variation and structure that suggest different reproductive strategies and dispersal abilities. This demonstrates that contrasting biological characteristics may arise in closely related lineages: Chaetomorpha moniliformis with dominant asexual reproduction and long dispersal abilities; Cladophora compacta with high genetic diversity, no population structure and likely to reproduce sexually; Cl. kursanovii with a structure congruent with geographic distribution and more restricted dispersal. The results suggest that polyploidy, rather than speciation with gene flow, is the force driving the reproductive isolation and evolution of this flock. Although many questions remain to be studied, this research provides the first insights into the diversification of this Cladophorales species flock and contributes to the understanding of speciation in freshwater algae.</p>


2010 ◽  
Vol 7 (4) ◽  
pp. 5011-5045 ◽  
Author(s):  
S. Trajanovski ◽  
C. Albrecht ◽  
K. Schreiber ◽  
R. Schultheiß ◽  
T. Stadler ◽  
...  

Abstract. Ancient Lake Ohrid on the Balkan Peninsula is considered to be the oldest ancient lake in Europe with a suggested Plio-Pleistocene age. Its exact geological age, however, remains unknown. Therefore, molecular clock data of Lake Ohrid biota may serve as an independent constraint of available geological data, and may thus also help to refine age estimates. Such evolutionary data may also help unravel potential biotic and abiotic factors that promote speciation events. Here, mitochondrial sequencing data of one of the largest groups of endemic taxa in Lake Ohrid, the leech genus Dina, is used to test whether it represents an ancient lake species flock, to study the role of horizontal and vertical barriers in Lake Ohrid for evolutionary events, to estimate the onset of intralacustrine diversification in this group based on molecular clock analyses, and to compare this data with data from other endemic species for providing an approximate time frame for the origin of Lake Ohrid. Based on the criteria speciosity, monophyly and endemicity, it can be concluded that Lake Ohrid Dina, indeed, represents an ancient lake species flock. Lineage sorting of its species, however, does not seem to be complete. Analyses of population structures of Dina spp. in the Ohrid watershed indicate a horizontal zonation of haplotypes from spring and lake populations, corroborating the role of lake-side springs, particularly the southern feeder springs, for evolutionary processes in endemic Ohrid taxa. Vertical differentiation of lake taxa, however, appears to be limited, though differences between populations from the littoral and the profundal are apparent. Molecular clock analyses indicate that the most recent common ancestor of extant species of this flock is approximately 1.99±0.83 Ma old, whereas the split of the Lake Ohrid Dina flock from a potential sister taxon outside the lake is estimated at 8.30±3.60 Ma. Comparisons with other groups of endemic Ohrid species indicated that in all cases, intralacustrine diversification started ≤2 Ma ago. Thus, this estimate may provide information on a minimum age for the origin of Lake Ohrid. Maximum ages are less consistent and generally less reliable. But cautiously, a maximum age of 3 Ma is suggested. Interestingly, this time frame of approximately 2–3 Ma for the origin of Lake Ohrid, generated based solely on evolutionary data, well fits the time frame most often used in the literature by geologists. Future studies must show whether this concurrence holds true.


Phytotaxa ◽  
2021 ◽  
Vol 528 (3) ◽  
pp. 191-201
Author(s):  
MARIA PATRICIA PERALTA ◽  
JOAQUÍN ALIAGA ◽  
OSVALDO DANIEL DELGADO ◽  
JULIA INÉS FARIÑA ◽  
BERNARDO ERNESTO LECHNER

In the context of a bioprospection programme for tyrosinase/L-DOPA- and melanin-producing fungal strains for biotechnological purposes, a hyperproducer isolate was obtained from Las Yungas rainforest, a relevant biodiverse ecoregion in North-Western Argentina. The selected strain was preliminarily identified as Paraboeremia sp. This is, to the best of our knowledge, the first native reported species of this genus in South America. Single-gene and multi-locus analyses of the internal transcribed spacer nuclear ribosomal RNA gene region (ITS), partial large subunit 28S nrDNA region (LSU), RNA polymerase II region (RPB2) and partial β-tubulin gene (TUB2) alignments were carried out to define the phylogenetic identity of this strain. As part of a polyphasic identification approach, these results were combined with morphological studies of active cultures growing on malt extract, oatmeal and potato dextrose agar plates. Incubation was performed under diverse conditions to stimulate sporulation for the subsequent micromorphological analysis. Microphotographs of pycnidia and conidia were taken with a scanning electron microscope. Maximum likelihood and Bayesian Inference analyses supported the location of the strain within the genus Paraboeremia, whilst morphological features allowed distinguishing it from previously described species within this genus. Based on the results herein reported, the new South-American species Paraboeremia yungensis is described and proposed.


Zootaxa ◽  
2004 ◽  
Vol 757 (1) ◽  
pp. 1
Author(s):  
DONALD W. WEBB ◽  
MARK A. METZ

The genus Nigranitida Metz is revised with the description of three new species, N. gibba Webb, N. irwini Webb, and N. margaretae Webb from Argentina. A key to the identification of the four species is included along with illustrations of the genitalia.


2007 ◽  
Vol 68 (3) ◽  
pp. 410-420 ◽  
Author(s):  
Sherilyn C. Fritz ◽  
Paul A. Baker ◽  
Geoffrey O. Seltzer ◽  
Ashley Ballantyne ◽  
Pedro Tapia ◽  
...  

AbstractA 136-m-long drill core of sediments was recovered from tropical high-altitude Lake Titicaca, Bolivia-Peru, enabling a reconstruction of past climate that spans four cycles of regional glacial advance and retreat and that is estimated to extend continuously over the last 370,000 yr. Within the errors of the age model, the periods of regional glacial advance and retreat are concordant respectively with global glacial and interglacial stages. Periods of ice advance in the southern tropical Andes generally were periods of positive water balance, as evidenced by deeper and fresher conditions in Lake Titicaca. Conversely, reduced glaciation occurred during periods of negative water balance and shallow closed-basin conditions in the lake. The apparent coincidence of positive water balance of Lake Titicaca and glacial growth in the adjacent Andes with Northern Hemisphere ice sheet expansion implies that regional water balance and glacial mass balance are strongly influenced by global-scale temperature changes, as well as by precessional forcing of the South American summer monsoon.


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