High-Throughput Sequencing for Life-History Sorting and for Bridging Reference Sequences in Marine Gerromorpha (Insecta: Heteroptera)

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jia Jin Marc Chang ◽  
Yin Cheong Aden Ip ◽  
Lanna Cheng ◽  
Ismael Kunning ◽  
Ralph R Mana ◽  
...  
Keyword(s):  
Life History ◽  
High Throughput Sequencing ◽  
Association Studies ◽  
Morphological Characters ◽  
Adult Males ◽  
Accurate Identification ◽  
Life History Stages ◽  
Coi Sequences ◽  
Primer Sets ◽  
Insect Taxonomy

Abstract Accurate identification and association of larval specimens with adults is a major challenge in insect taxonomy. Fortunately, it is now possible for nonexperts to sort collections of bulk samples with DNA barcodes rapidly and cost-effectively. We demonstrate this process using nanopore barcoding of 757 marine insects (Insecta: Gerromorpha), of which 81% were nymphs and many samples did not have co-occurring adult males for specific identification. We successfully associated 738 specimens (97%) to nine gerromorphan species, which would have been impossible to identify using morphological characters alone. This improved ability to incorporate information from all life-history stages has led to greater precision of species distributional ranges—knowledge that will be crucial for a more complete understanding of marine insects. We also highlighted two distinct, nonoverlapping Gerromorpha COI sequence databases on GenBank—a consequence of using two different primer sets to amplify different regions of COI. This issue inevitably hinders species identification with DNA-based methods, particularly for poorly represented groups such as marine insects. We bridged these databases by analyzing full-length COI sequences. We believe this will inspire future studies to incorporate DNA-based methods for more adult–larval association studies and for enhancing existing genetic resources, especially in understudied groups.

New species and findings of Pagastia Oliver (Diptera: Chironomidae: Diamesinae) from Central Asia, with DNA barcoding of known species of the genus

Zootaxa ◽  
2021 ◽  
Vol 4951 (3) ◽  
pp. 559-570
Author(s):  
EUGENYI A.  MAKARCHENKO ◽  
ALEXANDER A. SEMENCHENKO ◽  
DMITRY M. PALATOV
Keyword(s):  
New Species ◽  
Central Asia ◽  
Cytochrome Oxidase ◽  
Phylogenetic Trees ◽  
Morphological Characters ◽  
Molecular Data ◽  
Adult Males ◽  
Cytochrome Oxidase Subunit ◽  
Oxidase Subunit ◽  
Coi Sequences

Chironomids of the genus Pagastia Oliver (Diamesinae, Diamesini) from the mountains of Central Asia are revised using both morphological characters and molecular data. Illustrated descriptions of the adult male Pagastia (P.) caelestomontana sp. nov. from Kirgizstan and Tajikistan, P. (P.) hanseni sp. nov. from Tajikistan, and record of a finding apparently a new species P. (P.) aff. lanceolata (Tokunaga) from Tajikistan as well as an updated a key to the determination of the adult males of all known species of Pagastia are provided. A phylogenetic framework is reconstructed based on two mitochondrial genes cytochrome oxidase subunit I (COI) sequences of 34 samples belonging to 7 species of the genus Pagastia and cytochrome oxidase subunit II (COII) available for most samples. Phylogenetic trees of some known species of the genus Pagastia were reconstructed using the combined dataset and Bayesian inference (BI) and Maximum Likelihood (ML) methods. The interspecific K2P distances between seven Pagastia species including P. (P.) caelestomontana sp. nov., P. (P.) hanseni sp. nov. and undescribed P. (P.) aff. lanceolata (Tokunaga) are 6.3–13.2 which corresponding to species level. 

scholarly journals Identification of early life-history stages of Caribbean Apogon (Perciformes: Apogonidae) through DNA Barcoding

Zootaxa ◽  
2011 ◽  
Vol 3133 (1) ◽  
pp. 1 ◽  
Author(s):  
CAROLE C. BALDWIN ◽  
BALAM J. BRITO ◽  
DAVID G. SMITH ◽  
LEE A. WEIGT ◽  
ELVA ESCOBAR-BRIONES
Keyword(s):  
Life History ◽  
Early Life ◽  
Early Life History ◽  
Diagnostic Value ◽  
Morphological Characters ◽  
Genetic Lineage ◽  
Diagnostic Features ◽  
Genetic Lineages ◽  
Life History Stages ◽  
Central Atlantic

Early life-history stages of 12 of 17 species of western Central Atlantic Apogon were identified using molecular data. A neighbor-joining tree was constructed from mitochondrial cytochrome oxidase-c subunit I (COl) sequences, and genetic lineages of Apogon in the tree were identified to species based on adults in the lineages. Relevant portions of the tree subsequently were used to identify larvae of Apogon species from Carrie Bow Cay, Belize, and juveniles from Belize and other western Central Atlantic localities. Diagnostic morphological characters of larvae and juveniles were investigated by examining preserved vouchers from which the DNA was extracted and digital color photographs of those specimens taken before preservation. Orange and yellow chromatophore patterns are the easiest and sometimes only means of separating Apogon larvae. Patterns of melanophores and morphometric features are of limited diagnostic value. For juveniles, chromatophore patterns and the developing dark blotches characteristic of adults are the most useful diagnostic features. Larvae were identified for Apogon aurolineatus, A. binotatus, A. maculatus, A. mosavi, A. phenax, A. planifrons, and A. townsendi. Juveniles were identified for those species (except A. planifrons) and for A. pseudomaculatus, A. lachneri, A. pillionatus, A. robbyi, and A. quadrisquamatus. One larval specimen occurs in an unidentified genetic lineage, and five adults occur in another unidentified genetic lineage. Apogon species can be divided into at least four groups based on pigmentation patterns in early life stages. Further investigation is needed to determine if those groups are meaningful in the generic classification of Apogon species.

scholarly journals Overview of the Genetic Diversity of African Macrotermes (Termitidae: Macrotermitinae) and Implications for Taxonomy, Ecology and Food Science

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 518
Author(s):  
Bronwyn Egan ◽  
Zwannda Nethavhani ◽  
Barbara van Asch
Keyword(s):  
Negative Impact ◽  
Phylogenetic Reconstruction ◽  
Morphological Characters ◽  
Food Science ◽  
Cryptic Diversity ◽  
African Species ◽  
Genetic Groups ◽  
Wide Range ◽  
Coi Sequences ◽  
High Level

Macrotermes termites play important ecological roles and are consumed by many communities as a delicacy and dietary complement throughout Africa. However, lack of reliable morphological characters has hampered studies of Macrotermes diversity in a wide range of scientific fields including ecology, phylogenetics and food science. In order to place our preliminary assessment of the diversity of Macrotermes in South Africa in context, we analysed a comprehensive dataset of COI sequences for African species including new and publicly available data. Phylogenetic reconstruction and estimates of genetic divergence showed a high level of incongruity between species names and genetic groups, as well as several instances of cryptic diversity. We identified three main clades and 17 genetic groups in the dataset. We propose that this structure be used as a background for future surveys of Macrotermes diversity in Africa, thus mitigating the negative impact of the present taxonomic uncertainties in the genus. The new specimens collected in Limpopo fell into four distinct genetic groups, suggesting that the region harbours remarkable Macrotermes diversity relative to other African regions surveyed in previous studies. This work shows that African Macrotermes have been understudied across the continent, and that the genus contains cryptic diversity undetectable by classic taxonomy. Furthermore, these results may inform future taxonomic revisions in Macrotermes, thus contributing to advances in termitology.

Baetis majus sp. nov., new species of mayfly (Ephemeroptera: Baetidae) from Far East of Russia

Zootaxa ◽  
2021 ◽  
Vol 4965 (3) ◽  
pp. 541-557
Author(s):  
TATIANA M. TIUNOVA ◽  
ALEXANDER A. SEMENCHENKO ◽  
XIAOLI TONG
Keyword(s):  
New Species ◽  
Russian Far East ◽  
Far East ◽  
Morphological Characters ◽  
Species Group ◽  
Morphological Studies ◽  
Nearest Neighbours ◽  
Differential Identification ◽  
Coi Sequences ◽  
Western Palaearctic

A new species, Baetis majus Tiunova sp. nov., is described and illustrated based on larvae and reared adults discovered in the Russian Far East. The differential identification of this species was determined by the characteristics of other representatives of the genus Baetis Leach, including subgenera Baetis Leach and Tenuibaetis Kang & Yang from Eastern and Western Palaearctic, Nearctic and Oriental regions. In addition to morphological studies, DNA barcoding of the described species with average intraspecific K2P distances to nearest neighbours is documented. We reconstructed the phylogenetic relationships of all available cytochrome c oxidase subunit I (COI) sequences of the subgenera of Baetis and Tenuibaetis from four regions. Bayesian analysis using 47 morphological characters additional to partial COI sequences did not allow to determine the species-group of the Baetis genus to which the described species belongs. 

scholarly journals The movement ecology of seagrasses

2014 ◽  
Vol 281 (1795) ◽  
pp. 20140878 ◽  
Author(s):  
Kathryn McMahon ◽  
Kor-jent van Dijk ◽  
Leonardo Ruiz-Montoya ◽  
Gary A. Kendrick ◽  
Siegfried L. Krauss ◽  
...  
Keyword(s):  
Life History ◽  
Clonal Growth ◽  
Movement Ecology ◽  
Future Research ◽  
The Novel ◽  
Long Distance ◽  
Spatial And Temporal Scales ◽  
Life History Stages ◽  
Research Areas ◽  
Time Movement

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.

Further Observations on the Morphology of Heterodera schachtii, with Remarks on the Bionomics of a strain attacking Mangolds in Britain

1929 ◽  
Vol 7 (3) ◽  
pp. 119-140 ◽  
Author(s):  
Marjorie J. Triffitt
Keyword(s):  
Sugar Beet ◽  
Developmental Stages ◽  
Morphological Characters ◽  
Heterodera Schachtii ◽  
Adult Males ◽  
Morphological Variations ◽  
Size And Shape ◽  
Morphological Studies ◽  
Comparative Survey

In a previous publication the morphological characters of a strain of H. schachtii specialised on the potato in Lincolnshire were discussed. The size and shape of the brown cysts, size of the eggs and first stage larvæ and the general characters of the adult males of this strain were compared with those of a strain attacking potatoes in Rostock, Mecklenburg, for which the specific name H. rostochiensis was suggested by Wollenweber 1923.Considerable dimensional variations were found to exist in the Lincolnshire strain, and a study of the literature on the morphological characters of H. schachtii specialised on sugar-beet and oats, showed equally wide divergencies between the findings of different workers. A certain amount of preserved material of infected roots of beet and oats being available to the writer, as many developmental stages as possible were extracted from these, on which similar morphological studies were carried out. Thus a fairly complete comparative survey of H. schachtii specialised on beet, oats and potatoes was completed, and the morphological variations between the strains were found to be insufficient to justify the separation of the strain specialised on potato from those on beet and oats. The name H. rostochicnsis was, therefore, deemed a synonym for H. schachtii.

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