Cryptic Species in a “Living Fossil” Lineage: Taxonomic and Phylogenetic Relationships within the GenusLepidurus(Crustacea: Notostraca) in North America

King, Jamie L.; Hanner, Robert

doi:10.1006/mpev.1997.0470

Cited by 74 publications

(72 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The existence of sibling species among decapod crustaceans is widely reported in the literature (KNOWLTON, 1986;PALUMBI & BENZIE, 1991;FELDER & STATON, 1994;CUESTA & SCHUBART, 1998;GRANDJEAN et al, 1998;KING & HANNER, 1998;SCHUBART et al, 2000;STANTON et al, 2000). These investigators showed that closely related species are often hardly distinguished using morphologic characters, mainly due to their intraspecific variability.…”

Section: Discussionmentioning

confidence: 93%

Morphometric variability in populations of Palaemonetes spp. (Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin

García-Dávila

Magalhães

Hurtado-Guerrero

2005

Iheringia, Sér. Zool.

View full text Add to dashboard Cite

ABSTRACT. Morphometric variability among shrimp populations of the genus Palaemonetes Heller, 1869 from seven lakes (Huanayo and Urcococha, in Peru; Amanã, Mamirauá, Camaleão, Cristalino e Iruçanga, in Brasil) in the Amazon Basin, presumably belonging to Palaemonetes carteri Gordon, 1935 and Palaemonetes ivonicus Holthuis, 1950, were studied. The morphometric studies were carried out from the ratios obtained from the morphometric characters. Multivariated analysis (Principal Components Analysis-PCA, Discriminant Function Analysis and Cluster Analysis) were applied over the ratios. Intra-and interpopulation variations of the rostrum teeth, and the number of spines in the male appendix, were analyzed through descriptive statistics and bivariate analysis (Spearman Rank Correlation test). Results indicated a wide plasticity and overlapping in the studied ratios between populations. The Principal Components Analysis was not able to separate different populations, revealing a large intrapopulation plasticity and strong interpopulation similarity in the studied ratios. Although the Discriminant Functions Analysis was not able to fully discriminate populations, they could be allocated in three subgroups: 1) Cristalino and Iruçanga; 2) Huanayo, Urcococha and Camaleão and 3) Mamirauá and Amanã. The first two groups were morphometrically separated from each other, whereas the third one presented a strong overlap with the former two. The Cluster Analysis confirmed the first two subgroups separation, and indicated that the first and third groups were closely related. Rostrum teeth and number of spines in the appendix masculina showed a large intrapopulation variation and a strong overlapping among the studied populations, regardless of the species.KEYWORDS. Palaemonetes, morphometry, Amazon Basin, sibling species, freshwater shrimp. Holthuis, 1950. Os estudos morfométricos foram realizados a partir das razões obtidas dos caracteres morfométricos. Análise multivariada (análise de componentes principais, análise de função discriminante e análise de agrupamento hierárquico) foram aplicadas unicamente sobre as razões. Variações intra-e interpopulacionais do número de dentes de rostro, assim como do número de espinhos no apêndice masculino, foram analisadas mediante estatística descritiva e análise bivariada (teste de Spearman). Os resultados indicaram uma grande plasticidade e sobreposição nos caracteres diagnósticos entre as populações. A análise de componentes principais não conseguiu separar as diferentes populações, revelando uma grande plasticidade intrapopulacional e forte semelhança interpopulacional nas razões estudadas. Embora a análise de funções discriminantes não tenha logrado discriminar completamente as populações, estas ficaram alocadas em três subgrupos: 1) Cristalino e Iruçanga; 2) Huanayo, Urcococha e Camaleão e 3) Mamirauá e Amanã. Os primeiros dois grupos ficaram morfologicamente separados entre si, enquanto que o terceiro apresentou uma forte sobreposição com os dois anteriores. A análise de agrupamento hie...

show abstract

Section: Discussionmentioning

confidence: 93%

Morphometric variability in populations of Palaemonetes spp. (Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin

García-Dávila

Magalhães

Hurtado-Guerrero

2005

Iheringia, Sér. Zool.

View full text Add to dashboard Cite

show abstract

“…Over the past couple of decades, the advent of molecular techniques has uncovered a large degree of genetic diversity. Several species that were once considered cosmopolitan are now considered cryptic; in fact, discovery of cryptic species has grown exponentially (21,26,33,49,61). The most common current method of identifying cryptic species is based on the amount of genetic divergence as defined by genetic distances.…”

Section: Discussionmentioning

confidence: 99%

High-Level Genetic Diversity but No Population Structure Inferred from Nuclear and Mitochondrial Markers of the Peritrichous CiliateCarchesium polypinumin the Grand River Basin (North America)

Gentekaki

Lynn

2009

Appl Environ Microbiol

View full text Add to dashboard Cite

Studies that assess intraspecific genetic variation in ciliates are few and quite recent. Consequently, knowledge of the subject and understanding of the processes that underlie it are limited. We sought to assess the degree of intraspecific genetic variation in Carchesium polypinum (Ciliophora: Peritrichia), a cosmopolitan, freshwater ciliate. We isolated colonies of C. polypinum from locations in the Grand River basin in Southwestern Ontario, Canada. We then used the nuclear markers-ITS1, ITS2, and the hypervariable regions of the large subunit rRNA-and an 819-bp fragment of the mitochondrial cytochrome c oxidase I gene (cox-1) to investigate the intraspecific genetic variation of C. polypinum and the degree of resolution of the above-mentioned markers at the population level. We also sought to determine whether the organism demonstrated any population structure that mapped onto the geography of the region. Our study shows that there is a high degree of genetic diversity at the isolate level, revealed by the mitochondrial markers but not the nuclear markers. Furthermore, our results indicate that C. polypinum is likely not a single morphospecies as previously thought.Studies of intraspecific genetic variation in macroorganisms have provided insights into microevolutionary processes and speciation in these organisms. However, our understanding of the intraspecific genetic diversity of microbial eukaryotes and its temporal and spatial distribution is neither deep nor broad due to the limited number of studies that deal with these topics (2,5,7,31).Many of the studies assessing within-species genetic variation and its distribution have used random amplified polymorphic DNA (RAPD) fingerprinting. Typically, the amount of genetic variation is very low within a species (35,36,56), with some exceptions (20, 57). However, there are several problems arising from the use of RAPDs as the sole source of data, including reproducibility and scoring concerns (54).Sequences of the internal transcribed spacers (ITS), namely, ITS1 and ITS2, of the rRNA region have also been used to study the genetic diversity and population structure of protists (2, 6, 44). In several instances, the ITS sequences of populations of ciliates from across the globe have been nearly identical, indicating very low genetic variation (4, 13, 59, 62). On the other hand, the hypervariable regions of the large subunit (LSU) rRNA have revealed moderate genetic diversity in ciliates at the population level (15, 51).Mitochondrial DNA (mtDNA) has been employed only sparingly in population studies of protists, even though it is routinely used in similar studies of metazoans (3,7,8). Of the mitochondrial genes, the apocytochrome b gene (cob) and the cytochrome c oxidase I (cox-1) gene (cox-1) have been used for population-level analyses of ciliates. Estimation of intraspecific nucleotide diversity of the cob gene from three species of the prostome ciliate Coleps showed only minor differences (5). On the other hand, the cox-1 gene revealed genetic diversity that...

show abstract

“…Lynch (1966 redescribed Lepidurus lemmoni Holmes, 1894, treating L. lynchi as a synonym, and redescribed Lepidurus couesii Packard, 1875 (see Lynch, 1972) which had been treated as a synonym of L. apus apus by Longhurst (1955). Based on a preceding molecular study by King and Hanner (1998) and a morphological reinvestigation, Rogers (2001) reinstated Lepidurus packardi Simon, 1886 (treated as a subspecies of L. apus by Longhurst, 1955) and described a new species, Lepidurus cryptus Rogers, 2001. In addition, a new Central Asian species, Lepidurus mongolicus Vekhov, 1992 was discovered, leading to nine currently valid species in the genus Lepidurus.…”

Section: Introductionmentioning

confidence: 99%

Molecular phylogeny of the Notostraca

Korn

Rabet

Ghate³

et al. 2013

Molecular Phylogenetics and Evolution

View full text Add to dashboard Cite

a b s t r a c tWe used a combined analysis of one nuclear (28S rDNA) and three mitochondrial markers (COI, 12S rDNA, 16S rDNA) to infer the molecular phylogeny of the Notostraca, represented by samples from the six continents that are inhabited by this group of branchiopod crustaceans. Our results confirm the monophyly of both extant notostracan genera Triops and Lepidurus with good support in model based and maximum parsimony analyses. We used branchiopod fossils as a calibration to infer divergence times among notostracan lineages and accounted for rate heterogeneity among lineages by applying relaxed-clock models. Our divergence date estimates indicate an initial diversification into the genera Triops and Lepidurus in the Mesozoic, most likely at a minimum age of 152.3-233.5 Ma, i.e., in the Triassic or Jurassic. Implications for the interpretation of fossils and the evolution of notostracan morphology are discussed. We further use the divergence date estimates to formulate a biogeographic hypothesis that explains distributions of extant lineages predominantly by overland dispersal routes. We identified an additional hitherto unrecognised highly diverged lineage within Lepidurus apus lubbocki and three additional previously unknown major lineages within Triops. Within T. granarius we found deep differentiation, with representatives distributed among three major phylogenetic lineages. One of these major lineages comprises T. cancriformis, the T. mauritanicus species group and two hitherto unrecognised T. granarius lineages. Samples that were morphologically identified as T. granarius diverged from the most basal nodes within this major lineage, and divergence dates suggested an approximate age of 23.7-49.6 Ma for T. cancriformis, indicating the need for a taxonomic revision of Triassic and Permian fossils that are currently attributed to the extant T. cancriformis. We thus elevate T. cancriformis minor to full species status as Triops minor Trusheim, 1938 and include in this species the additional Upper Triassic samples that were attributed to T. cancriformis. We further elevate T. cancriformis permiensis to full species status as Triops permiensis Gand et al., 1997.

show abstract

Cryptic Species in a “Living Fossil” Lineage: Taxonomic and Phylogenetic Relationships within the GenusLepidurus(Crustacea: Notostraca) in North America

Cited by 74 publications

References 47 publications

Morphometric variability in populations of Palaemonetes spp. (Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin

Morphometric variability in populations of Palaemonetes spp. (Crustacea, Decapoda, Palaemonidae) from the Peruvian and Brazilian Amazon Basin

High-Level Genetic Diversity but No Population Structure Inferred from Nuclear and Mitochondrial Markers of the Peritrichous CiliateCarchesium polypinumin the Grand River Basin (North America)

Molecular phylogeny of the Notostraca

Contact Info

Product

Resources

About