The bearing of Phoxinus (Cyprinidae) hybridity on the classification of its North American species

1970 ◽  
Vol 48 (6) ◽  
pp. 1167-1177 ◽  
Author(s):  
Pierre Legendre
Keyword(s):  
Chromosome Number ◽  
Discriminant Function ◽  
North American ◽  
Parental Species ◽  
North American Species ◽  
Discriminant Functions

Three populations of Phoxinus eos × P. neogaeus were found to form single Mendelian populations, by comparison with the parental species through a discriminant function. The hybrids of one of these populations were found to be fertile. A fourth hybrid collection, studied by three discriminant functions, was found to contain Semotilus margarita, P. eos × P. neogaeus, and hybrids of S. margarita with at least P. eos, but possibly P. eos × P. neogaeus. The presence of this hybrid, when related to the chromosome number of the species concerned, suggests the transfer of S. margarita to the genus Phoxinus.

A Note on Synchronized Emergence in Gomphus vastus Walsh (Odonata: Gomphidae)

1963 ◽  
Vol 95 (1) ◽  
pp. 69-69 ◽  
Author(s):  
Clifford Johnson
Keyword(s):  
North American ◽  
Adult Emergence ◽  
North American Species ◽  
Ecological Classification ◽  
General Area ◽  
River Bank ◽  
Dragonfly Species

An ecological classification of dragonfly species into spring and summer types was proposed by Corbet (1954). Much of the basis for the classification rests with the pattern and period of adult emergence. Since little information of this type is known for North American species, the following observations are reported.On May 20, 1962, I spent several hours collecting Baisaeschna janata and Didymops transversa along the New River, two miles north of McCoy, Virginia. A search was made at that time for odonate exuviae. None were found. I returned to the site at 9:30 a.m. the following day. The vegetation, tree trunks, rocks and detritus along the river were clustered with exuviae, all apparently of Gomphus vastus. Several thousand individuals must have emerged from that general area of the river. As an example of the density, 230 cast skins were counted along one 20-foot stretch of the river bank. Some individuals had transformed directly on the sand banks and others at a height of seven feet.

A TAXONOMIC STUDY OF WESTERN CANADIAN SPECIES IN THE GENUS BETULA

1966 ◽  
Vol 44 (7) ◽  
pp. 929-1007 ◽  
Author(s):  
Janet R. Dugle
Keyword(s):  
Gene Flow ◽  
Chromosome Number ◽  
North American ◽  
Parental Species ◽  
Environmental Influence ◽  
Taxonomic Study ◽  
Environmental Selection ◽  
First Time ◽  
Lower Chromosome Number

Five western North American birches, Betula fontinalis, B. glandulosa, B. glandulifera, B. resinifera, and B. papyrifera, are studied taxonomically. Four hybrids, B. × winteri, B. × sargentii, B. × arbuscula, and B. × uliginosa, are described for the first time and three others, B. × utahensis, B. × eastwoodae, and B. × sandbergii, are also included. Populations formed when species are in contact have been analyzed and the nature of several hybrid entities determined. B. × uliginosa results from B. resinifera × B. glandulifera. In this population, introgression is toward B. glandulifera, which has the higher chromosome number. B. glandulifera also hybridizes with B. glandulosa producing B. × sargentii. Most gene flow is toward B. glandulifera, which has the higher chromosome number. In B. glandulosa × B. fontinalis (B. × eastwoodae) introgression was little influenced by environmental selection, the hybrid was as common as either parental species, and any gene flow was in either direction. B. × utahensis results from B. papyrifera × B. fontinalis. Introgression is toward B. papyrifera. Hybridization of B. × sargentii and B. papyrifera produces B. × arbuscula, a rare hybrid. Hybridization of B. resinifera and B. papyrifera results in B. × winteri, with introgression in both directions. B. × sandbergii results from B. papyrifera × B. glandulifera. Probably as a result of environmental influence in the analysis area, introgression was toward B. glandulifera, with the lower chromosome number.

The Classification of Larval Tabanidae

1964 ◽  
Vol 96 (1-2) ◽  
pp. 159-159
Author(s):  
H. J. Teskey
Keyword(s):  
Life History ◽  
North American ◽  
Life Histories ◽  
North American Species ◽  
Immature Stages ◽  
Larval Habitats ◽  
The North

Relatively little is known of the life history, ecology and behaviour of most species of Tabanidae. Knowledge of their immature stages is particularly deficient. The larvae of only 46, or about ⅛, of the North American species have been described and many of these descriptions are inadequate. The present research was initiated in 1960 to describe and classify tabanid larvae and to contribute information on larval habitats and life histories.

scholarly journals Phylogeny and classification of the genus-group taxa of Loxandrina (Coleoptera, Carabidae, Abacetini)

2020 ◽  
Vol 67 (2) ◽  
pp. 151-182
Author(s):  
Kipling Will
Keyword(s):  
North American ◽  
Phylogenetic Relationships ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Historical Biogeography ◽  
North American Species ◽  
Diagnostic Features ◽  
Genus Level

Bayesian and parsimony phylogenetic analyses of combined and partitioned datasets of molecular (partial sequences of 28S, wg, COI, and CAD) and morphological (51 characters of adults) data for exemplar taxa of five outgroup and 76 ingroup abacetine carabids resulted in a monophyletic Loxandrina Erwin & Sims, 1984 that is split into Australian and American clades. The genus Loxandrus LeConte, 1853 as previously delimited is not monophyletic relative to numerous genus-level taxa in Abacetini Chaudoir, 1873 and is restricted to a subgenus of North American species. A reclassification and nomenclatural changes for the subtribe that are consistent with the phylogeny are provided. Three genera are removed from Loxandrina: Aulacopodus Britton, 1940 moved to Pterostichini Bonelli, 1810; Cosmodiscus Sloane, 1907 and Tiferonia Darlington, 1962 moved to Abacetina. Based on the phylogenetic relationships and nomenclatural priority only four genera are recognized in Loxandrina: Cerabilia Laporte, 1867, Zeodera Laporte, 1867, Pediomorphus Chaudoir, 1878, and Oxycrepis Reiche, 1843. All other previously recognized genera are treated as subgenera. The classification change created eight secondary homonyms that are resolved by the proposal of the following: Oxycrepis gebi, replacement name for O. balli (Straneo, 1993); O. amatona, replacement name for O. matoana (Straneo, 1993); O. xiproma, replacement name for O. proxima (Straneo, 1993); O. rasutulis, replacement name for O. suturalis (Straneo, 1993); O. laevinota, replacement name for O. laevicollis (Bates, 1871); O. arvulap, replacement name for O. parvula (Straneo, 1951); O. noaffine, replacement name for O. affinis (Straneo, 1991); O. alutona, replacement name for O. notula (Tschitschérine, 1901). An overview of the morphological characteristics and diagnostic features of Loxandrina taxa is provided. A key and habitus images are provided for identification of genera and subgenera. The possible historical biogeography of the group is discussed in light of their phylogenetic relationships and past geological events.

REVISION OF NORTH AMERICAN AGABUS LEACH (COLEOPTERA: DYTISCIDAE): INTRODUCTION, KEY TO SPECIES GROUPS, AND CLASSIFICATION OF THE AMBIGUUS-, TRISTIS-, AND ARCTICUS-GROUPS

1989 ◽  
Vol 121 (10) ◽  
pp. 861-919 ◽  
Author(s):  
D.J. Larson
Keyword(s):  
North America ◽  
North American ◽  
North American Species ◽  
Key To Species ◽  
Diagnostic Characters ◽  
Ecological Information ◽  
The North ◽  
Species Groups ◽  
Diving Beetle

AbstractThe first of a planned series of papers revising the Nearctic species of the predaceous diving beetle genus, Agabus Leach, is presented. The genus is defined in the broad sense of Sharp (1882) and Fall (1922). The North American species are divided into species groups and diagnostic characters for group recognition are summarized in a key. Assignment of species to these groups is indicated in a checklist of North American species. The ambiguus-, tristis-, and arcticus-groups are defined, their relationships discussed, and included species revised. The ambiguus-group, which is restricted to North America, contains the species A. ambiguus (Say), A. strigulosis (Crotch), A. erythropterus (Say), A. austinii Sharp, and A. klamathensis sp.nov. The tristis-group, which has a Holarctic distribution, contains two species in North America, A. tristis Aubé and A. leptapsis (LeConte). The Holarctic arcticus-group is represented by A. arcticus (Paykull) and A. anthracinus (Mannerheim) in North America. For each species, patterns of variation are described, the North American distributions mapped, and ecological information summarized.

BASIC CHROMOSOME NUMBER, CYANOGENETIC GLUCOSIDE VARIATION, AND GEOGRAPHIC DISTRIBUTION OF LOTUS SPECIES

1967 ◽  
Vol 45 (5) ◽  
pp. 639-647 ◽  
Author(s):  
William F. Grant ◽  
B. S. Sidhu
Keyword(s):  
Chromosome Number ◽  
Geographic Distribution ◽  
North American ◽  
New World ◽  
Basic Chromosome Number ◽  
North American Species ◽  
Hydrocyanic Acid ◽  
Basic Chromosome ◽  
Fresh Leaf ◽  
The North

Leaves of 51 species and three varieties of Lotus (Leguminosae) were assessed quantitatively for hydrocyanic acid (HCN) reaction intensity and the data correlated with basic chromosome number and geographic distribution. The presence of HCN was determined from 0.05 grams of fresh leaf samples by the picric acid – filter paper technique. A gradation of 10 different color reactions (−), (±), and (+1 to +8) was used to compare the HCN reaction for each species. On the basis of potassium cyanide equivalents, each gram of fresh leaf material was estimated to contain an amount of HCN which varied between the different plants and accessions from 0.5 mg to 750 mg. Most of the Old World species were positive for HCN, whereas the reverse was true for the North American species. This would favor the previous separation of the North American species into a separate genus Hosackia. All of the n = 7 species have a greater concentration of HCN than the n = 6 species in both the Old and New World. None of the n = 6 species in the New World reacted positively. Therefore, there was a reduction of HCN with evolutionary development. Two colchicine-induced tetraploids (4x = 24, 28) gave a lower HCN reaction than their diploid counterparts. Leaves of L. siliquosus (n = 7) reacted negatively to the HCN test; however, the cotyledons gave a highly positive reaction supporting the retention of the generic name Tetragonolobus (T. siliquosus (L.) Roth.) for this species. Chromosome number determinations are reported for the first time for L. holosericeus Webb and Berth. (2n = 14), L. mascaensis Buchard (2n = 28), L. nevadensis Greene (2n = 14), L. helleri Britton (2n = 14), and L. oblongifolius var. nevadensis (Gray) Munz (2n = 14).

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