Gross stomach morphology in akodontine rodents (Cricetidae: Sigmodontinae: Akodontini): a reappraisal of its significance in a phylogenetic context

2020 ◽  
Vol 101 (3) ◽  
pp. 835-857 ◽  
Author(s):  
Ulyses F J Pardiñas ◽  
Carola Cañón ◽  
Carlos A Galliari ◽  
Jorge Brito ◽  
Nuria Bernal Hoverud ◽  
...  

Abstract Akodontini, the second largest tribe within sigmodontine rodents, encompasses several stomach morphologies. This is striking because most sigmodontine groups of comparable taxonomic rank are very conservative in this respect. Based on extensive sampling of newly dissected specimens (213 stomachs representing 36 species), as well as published examples, covering almost all akodontine living genera (15 of 16), we undertook a reappraisal of the gross morphology of this organ. We then mapped this information, together with gallbladder occurrence, in a refined multilocus molecular phylogeny of the tribe. We surveyed three different configurations of stomachs in akodontines, according to the degree of development and location of the glandular epithelium; in addition, two minor variations of one of these types were described. Of the five major clades that integrate Akodontini, four are characterized by a single stomach morphology, while one clade exhibits two morphologies. Mapping stomach type on the phylogeny recovered two configurations for the most recent ancestor of Akodontini. A revised survey of gallbladder evidence also revealed overlooked congruencies. The observed stomach diversity and its arrangement in the phylogeny, along with additional morphological characters and the genetic diversity among the main clades, supports the necessity of changes in the current classification of the tribe. Recognition of subtribes or partitioning of Akodontini into several additional tribes of equal rank could be suitable options.

2016 ◽  
Vol 47 (1) ◽  
pp. 53-82 ◽  
Author(s):  
Werner P. Strümpher ◽  
Martin H. Villet ◽  
Catherine L. Sole ◽  
Clarke H. Scholtz

Extant genera and subgenera of the Trogidae (Coleoptera: Scarabaeoidea) are reviewed. Contemporary classifications of this family have been based exclusively on morphological characters. The first molecular phylogeny for the family recently provided strong support for the relationships between morphologically defined genera and subgenera. On the basis of morphological, molecular and biogeographical evidence, certain taxonomic changes to the genus-level classification of the family are now proposed. The family is confirmed as consisting of two subfamilies, Omorginae Nikolajev and Troginae MacLeay, the former with two genera,OmorgusErichson andPolynoncusBurmeister, and the latter with two genera,TroxFabricius andPhoberusMacLeaystat. rev.Phoberusis restored to generic rank to include all Afrotropical (including Madagascan endemic) species;Afromorgusis confirmed at subgeneric rank within the genusOmorgus; and the monotypic Madagascan genusMadagatroxsyn. n.is synonymised withPhoberus.The current synonymies ofPseudotroxRobinson (withTrox),ChesasBurmeister,LagopelusBurmeister andMegalotroxPreudhomme de Borre (all withOmorgus) are all accepted to avoid creating speculative synonyms before definitive phylogenetic evidence is available. New combinations resulting from restoringPhoberusto a monophyletic genus are listed in Appendix A.


2020 ◽  
Vol 5 (1) ◽  
pp. 17-38 ◽  
Author(s):  
K. Seto ◽  
S. Van Den Wyngaert ◽  
Y. Degawa ◽  
M. Kagami

During the last decade, the classification system of chytrids has dramatically changed based on zoospore ultrastructure and molecular phylogeny. In contrast to well-studied saprotrophic chytrids, most parasitic chytrids have thus far been only morphologically described by light microscopy, hence they hold great potential for filling some of the existing gaps in the current classification of chytrids. The genus Zygorhizidium is characterized by an operculate zoosporangium and a resting spore formed as a result of sexual reproduction in which a male thallus and female thallus fuse via a conjugation tube. All described species of Zygorhizidium are parasites of algae and their taxonomic positions remain to be resolved. Here, we examined morphology, zoospore ultrastructure, host specificity, and molecular phylogeny of seven cultures of Zygorhizidium spp. Based on thallus morphology and host specificity, one culture was identified as Z. willei parasitic on zygnematophycean green algae, whereas the others were identified as parasites of diatoms, Z. asterionellae on Asterionella, Z. melosirae on Aulacoseira, and Z. planktonicum on Ulnaria (formerly Synedra). According to phylogenetic analysis, Zygorhizidium was separated into two distinct order-level novel lineages; one lineage was composed singly of Z. willei, which is the type species of the genus, and the other included the three species of diatom parasites. Zoospore ultrastructural observation revealed that the two lineages can be distinguished from each other and both possess unique characters among the known orders within the Chytridiomycetes. Based on these results, we accommodate the three diatom parasites, Z. asterionellae, Z. melosirae, and Z. planktonicum in the distinct genus Zygophlyctis, and propose two new orders: Zygorhizidiales and Zygophlyctidales.


2019 ◽  
Vol 104 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Mónica M. Carlsen ◽  
Thomas B. Croat

This study presents an evaluation of the currently accepted sectional classification of the genus Anthurium Schott (Araceae) in light of a recently published molecular phylogeny for the group. In general, disagreements between these two occur because many diagnostic morphological characters used in the sectional classification turned out to be highly homoplasious within Anthurium, with multiple independent gains or losses of seemingly similar morphologies in distantly related clades. A new sectional classification of Anthurium that more accurately represents species relationships and the evolutionary history of the genus is much needed, and here we propose the first steps toward it. Results from this study suggest that out of the 18 sections and two series recognized in Anthurium, only seven of these groups are monophyletic (i.e., sections Andiphilum (Schott) Croat, Calomystrium (Schott) Engl., Dactylophyllium (Schott) Engl., Leptanthurium (Schott) Engl., Polyphyllium Engl., Tetraspermium (Schott) Engl., and the newly recognized section Multinervia (Croat) Carlsen & Croat, previously a series within section Pachyneurium (Schott) Engl.). All other sections are either not monophyletic or their monophyly could not be accurately tested. A complete revision of the sectional classification of Anthurium will require a more comprehensive taxon sampling and a better supported molecular phylogeny.


Zootaxa ◽  
2013 ◽  
Vol 3610 (1) ◽  
pp. 1-80 ◽  
Author(s):  
J. K. LOWRY ◽  
A. A. MYERS

The Amphipoda includes a large clade defined by the presence of a previously unrecognised synapomorphy, apical robust setae on the rami of uropods 1–2. We term this clade the Senticaudata subord. nov. (Latin: sentis = thorn). It includes almost all freshwater species as well as a number of marine benthic taxa, formerly part of the ‘Gammaridea’. The phylogeny of the senticaudates was determined by cladistic analysis of morphological characters and character states. Within the suborder Senticaudata there are six infraorders: Carangoliopsida, Talitrida, Hadziida, Corophiida, Bogidiellida and Gammarida. A classification is provided and all the senticaudate families are diagnosed. We introduce for the first time in amphipod classification, the level parvorder between infraorder and superfamily. Four new families are described: Kairosidae; Eriopisidae; Nuuanuidae and Kergueleniolidae.


ZooKeys ◽  
2021 ◽  
Vol 1047 ◽  
pp. 155-198
Author(s):  
Fernando L. Mantelatto ◽  
Leonardo G. Pileggi ◽  
João A. F. Pantaleão ◽  
Célio Magalhães ◽  
José Luis Villalobos ◽  
...  

The freshwater shrimp genus Cryphiops Dana, 1852 has a disjunct distribution in North (Mexico) and South (Brazil, Chile) America, and is composed of only six species. The current classification of genera in the Palaemonidae is controversial, based on variable morphological characters, and still far from a clear definition. Cryphiops differs from the speciose genus Macrobrachium Spence Bate, 1868 only by the absence of the hepatic spines on the carapace. Previous studies with a limited dataset suggested the necessity to link morphology and phylogeny to create an internal rearrangement in the genus to resolve the paraphyletic status. Through a molecular phylogenetic approach, the evolutionary relationships are inferred based on four (mitochondrial and nuclear) genes, among all recognized species of Cryphiops and, in combination with a taxonomic revision, a rearrangement in the systematics of the genus is suggested. The absence of hepatic spines on the carapace, the only character used to separate the genus Cryphiops, is subjective and should be considered as a homoplasy. This implies that Cryphiops and Macrobrachium are subjective synonyms and, because the latter genus is much more diverse and widely known, with several economically important species, to avoid confusion and disturbance in nomenclatural stability and keep universality, a proposal for the priority of the older synonym (Cryphiops) to be partially suppressed in favor of maintaining the prevailing use of the younger synonym (Macrobrachium) is presented. As the species of Cryphiops should be accommodated in the genus Macrobrachium, new names to replace three preoccupied specific names that, by this action, resulted to be secondary homonyms are offered.


2004 ◽  
Vol 59 (7-8) ◽  
pp. 572-578 ◽  
Author(s):  
Arup Kumar Mukherjee ◽  
Laxmikanta Acharya ◽  
Pratap Chandra Panda ◽  
Trilochan Mohapatra ◽  
Premananda Das

AbstractRandom amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers were used to study the genomic relationship among 11 members of Indian Rhizophoraceae represented by nine true mangroves and two non-mangrove species. The AFLP and RAPD bands were scored and analyzed for genetic similarities and cluster analysis was done which separated the 11 species studied into two main groups, the true mangroves and the non-mangroves. The polymorphism observed for these markers showed a high degree of genetic diversity among the constituent taxa of the family. The phylogenetic relationship inferred from molecular marker systems supported the traditional taxonomic classification of the family Rhizophoraceae based on morphological characters at the levels of tribe, phylogeny and delimitation of genera and species, except the intra-generic classification of the genus Bruguiera and the placement of Rhizophora in the family Rhizophoraceae.


Insects ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Petr Kočárek ◽  
Ivona Horká ◽  
Robin Kundrata

Zoraptera is a small and predominantly tropical insect order with an unresolved higher classification due to the extremely uniform external body morphology. We, therefore, conducted a multigene molecular phylogeny of extant Zoraptera and critically re-evaluated their morphological characters in order to propose a natural infraordinal classification. We recovered a highly-resolved phylogeny with two main clades representing major evolutionary lineages in Zoraptera, for which we propose family ranks. The two families exhibit striking differences in male genitalia and reproductive strategies. Each family contains two subclades (subfamilies) supported by several morphological synapomorphies including the relative lengths of the basal antennomeres, the number and position of metatibial spurs, and the structure of male genitalia. The newly proposed higher classification of Zoraptera includes the family Zorotypidae stat. revid. with Zorotypinae Silvestri, 1913 (Zorotypus stat. revid., Usazoros Kukalova-Peck and Peck, 1993 stat. restit.) and Spermozorinae subfam. nov. (Spermozoros gen. nov.), and Spriralizoridae fam. nov. with Spiralizorinae subfam. nov. (Spiralizoros gen. nov., Scapulizoros gen. nov., Cordezoros gen. nov., Centrozoros Kukalova-Peck and Peck, 1993, stat. restit., Brazilozoros Kukalova-Peck and Peck, 1993, stat. restit.), and Latinozorinae subfam. nov. (Latinozoros Kukalova-Peck and Peck, 1993, stat. restit.). An identification key and morphological diagnoses for all supraspecific taxa are provided.


Genome ◽  
2001 ◽  
Vol 44 (6) ◽  
pp. 941-946
Author(s):  
Laurent Marché ◽  
Sylvie Valette ◽  
Eric Grenier ◽  
Didier Mugniéry

Amplified fragment length polymorphism (AFLP) was used to obtain information on the within-species genetic variability of the tobacco cyst – nematode (TCN) complex. AFLP was found to be well suited to this type of study. The current classification of TCN was confirmed. Results indicate that the Globodera tabacum solanacearum group, believed to be restricted to the U.S.A., also occurs in Mexico. The within-species variability of TCN is considerable. Populations from Mexico may form a new subgroup. AFLP group-specific markers were identified for two of the TCN subgroups: Globodera tabacum tabacum and Globodera tabacum solanacearum.Key words: Heteroderinae, classification, markers, genetic diversity, geographic distribution.


Zootaxa ◽  
2018 ◽  
Vol 4474 (1) ◽  
pp. 1 ◽  
Author(s):  
HANS FERY ◽  
IGNACIO RIBERA

The subtribe Deronectina Galewski, 1994 (Dytiscidae, Hydroporinae, Hydroporini) is distributed in the Nearctic, in the north of the Neotropical region, and in the Palaearctic and Afrotropical regions. It is currently composed of 194 species and 13 subspecies in eight genera: Amurodytes Fery & Petrov, 2013, Boreonectes Angus, 2010, Deronectes Sharp, 1882, Nebrioporus Régimbart, 1906, Oreodytes Seidlitz, 1887, Scarodytes Gozis, 1914, Stictotarsus Zimmermann, 1919, and Trichonectes Guignot, 1941. We present a morphological and a molecular phylogeny of the species of the subtribe, and a revision of their taxonomy to accommodate our phylogenetic results. The morphological phylogeny is based on the study of 54 characters of the adults of 189 species and 2 subspecies, of which 114 species and the 2 subspecies were coded in the morphological matrix. For the molecular phylogeny we investigated 115 species and 11 subspecies, using a combination of fragments of four mitochondrial (COI, 16S rRNA, tRNA-Leu and NAD1) and two nuclear genes (18S rRNA and H3), analysed with maximum likelihood and Bayesian methods. For both datasets we included the type species of all genus-group taxa. The morphological, molecular and combined phylogenies mostly agree with the current classification of the group, but in some cases our results are in contradiction with established genera. Most remarkable are the polyphyly of Stictotarsus and Nebrioporus, the low support for the monophyly and internal phylogeny of Oreodytes, and the low support for the monophyly of Deronectina with molecular data. Thus, we introduce some taxonomic changes in the current classification to accommodate the generic concepts to our phylogenetic results. Nine new genera are established: Clarkhydrus n. gen. (type species Hydroporus roffii Clark, 1862), Hornectes n. gen. (type species Hydroporus quadrimaculatus Horn, 1883), Iberonectes n. gen. (type species Deronectes bertrandi Legros, 1956), Larsonectes n. gen. (type species Potamonectes minipi Larson, 1991), Leconectes n. gen. (type species Hydroporus striatellus LeConte, 1852), Mystonectes n. gen. (type species Deronectes neomexicanus Zimmerman & Smith, 1975), Nectoboreus n. gen. (type species Hydroporus aequinoctialis Clark, 1862), Nectomimus n. gen. (type species Oreodytes okulovi Lafer, 1988), and Zaitzevhydrus n. gen. (type species Hydroporus formaster Zaitzev, 1908). Three genera are reinstated as valid: Deuteronectes Guignot, 1945 (stat. rest.) (type species Hydroporus picturatus Horn, 1883), Nectoporus Guignot, 1950 (stat. rest.) (type species Hydroporus abbreviatus Fall, 1923), and Neonectes J. Balfour-Browne, 1940 (stat. rest.) (type species Hydroporus natrix Sharp, 1884). Thirty-six new combinations for species and subspecies thus far treated in the genera Boreonectes, Nebrioporus, Oreodytes and Stictotarsus result from the new classification: Clarkhydrus corvinus (Sharp, 1887) n. comb., C. decemsignatus (Clark, 1862) n. comb., C. deceptus (Fall, 1932) n. comb., C. eximius (Motschulsky, 1859) n. comb., C. falli (Nilsson, 2001) n. comb., C. interjectus (Sharp, 1882) n. comb., C. minax (Zimmerman, 1982) n. comb., C. opaculus (Sharp, 1882) n. comb., C. roffii (Clark, 1862) n. comb., C. spectabilis (Zimmerman, 1982) n. comb., Deuteronectes angustior (Hatch, 1928) n. comb., Hornectes quadrimaculatus (Horn, 1883) n. comb., Iberonectes bertrandi (Legros, 1956) n. comb., Larsonectes minipi (Larson, 1991) n. comb., Leconectes striatellus (LeConte, 1852) n. comb., Mystonectes coelamboides (Fall, 1923) n. comb., M. grammicus (Sharp, 1887) n. comb., M. neomexicanus (Zimmerman & Smith, 1975) n. comb., M. panaminti (Fall, 1923) n. comb., M. titulus (Leech, 1945) n. comb., Nectoboreus aequinoctialis (Clark, 1862) n. comb., N. dolerosus (Leech, 1945) n. comb., N. funereus (Crotch, 1873) n. comb., Nectomimus okulovi (Lafer, 1988) n. comb., Nectoporus angelinii (Fery, 2015) n. comb., N. congruus (LeConte, 1878) n. comb., N. crassulus (Fall, 1923) n. comb., N. obesus obesus (LeConte, 1866) n. comb., N. obesus cordillerensis (Larson, 1990) n. comb., N. rhyacophilus (Zimmerman, 1985) n. comb., N. sanmarkii sanmarkii (C.R. Sahlberg, 1826) n. comb., N. sanmarkii alienus (Sharp, 1873) n. comb., N. sierrae (Zimmerman, 1985) n. comb., N. subrotundus (Fall, 1923) n. comb., Zaitzevhydrus formaster formaster (Zaitzev, 1908) n. comb., and Z. formaster ulanulana (C.-K. Yang, 1996) n. comb. 


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