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ELLEN M. RASCH GRACE A. WYNGAARD 《Biological journal of the Linnean Society. Linnean Society of London》2006,87(4):625-635
Genome sizes for 36 species of cyclopoid copepods were determined by DNA-Feulgen cytophotometry of nuclei from adults collected from diverse habitats and locales in North America, South America, Europe, and Asia. Genome sizes are small, show a 20-fold range ( C = 0.10–2.02 pg DNA), and vary in a discontinuous fashion. The genomes of cyclopoid copepods are remarkably small and constant within each species, unlike the large and variable genomes of marine calanoid species. These differences may reflect the evolutionary antiquity of marine copepods in relation to marine, brackish, and freshwater copepods, as well as differences in mechanisms used to modulate genome size. The small genome sizes of contemporary cyclopoids provide substantive evidence of evolutionary constraint, possibly favouring small genomes, rapid replication rates and accelerated development as adaptive strategies for survival in often fragmented, stressful, and changing habitats. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 625–635. 相似文献
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Quantitative assessment of species identification in aerial transect surveys for ice‐associated seals
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Brett T. McClintock Erin E. Moreland Joshua M. London Shawn P. Dahle Gavin M. Brady Erin L. Richmond Kymberly M. Yano Peter L. Boveng 《Marine Mammal Science》2015,31(3):1057-1076
Technological advances have facilitated collection of vast quantities of photographic data from aerial surveys of marine mammals. However, when it is difficult to distinguish species from a distance, reliable identification from aerial images can often be challenging. This is the case for ice‐associated seals, species for which global climate change has motivated intensive monitoring efforts in recent years. We assess species and age class identification from aerial images of four ice seal species (bearded seals, Erignathus barbatus; ribbon seals, Histriophoca fasciata; ringed seals, Pusa hispida; spotted seals, Phoca largha) in the Bering Sea. We also investigate the specific phenomenological and behavioral traits commonly associated with species identification and observer confidence. We generally found species and age class misidentification occurred at relatively low levels, but only 83% of spotted seals tended to be correctly identified (with 11% mistaken as ribbon seals). We also found certain traits were strong predictors for observed species, age class, or observer confidence. Our findings add to the growing body of evidence that species misidentification is pervasive in passive sampling of animal populations. Even low levels of misidentification have been demonstrated to induce substantial biases in estimators of species distribution and abundance, and it is important that statistical models account for such errors. 相似文献
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RONG-JING ZHANG REN-ZHANG ZHOU FU-WU XING HONG-FENG CHEN 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(2):289-292
Magnolia polytepala Law, R.Z. Zhou & R.J. Zhang sp. nov. (Magnoliaceae) a new species from Fujian, south-east China, is described and illustrated. The species was found growing only in the evergreen broad-leaved forests of Mount Wuyishan at altitudes of 500–1200 m. Notes are also presented on the phenology and conservation status of the new species. It is closely related to Magnolia liliiflora Desr., but differs from the latter in its stunted habit (less than 2 m tall) and tepals, which are more numerous (12–16) and not contorted at the base. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 289–292. 相似文献
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A new species of the thermophylic Tethyan relict prawn Typhlatya is described from two anchialine caves near Perpignan (southern France). The new species is closely related to a congener known only from a freshwater cave at Castellón (eastern Spain), about 400 km to the south-west, differing apparently only in the size and shape of the rostrum and the armature of the dactylus of the fifth pereiopod. Based on palaeogeographical evidence and assuming a sister-group relationship between both species, we suggest that their common ancestor could not be older than early Pliocene in age, and that it was already a stygobiont taxon adapted to live in shallow-water marine crevicular habitats. This ancestor would have vanished from the western Mediterranean after the cooling associated with the onset of northern Hemisphere glaciation, about 3 Mya, as documented for other Mediterranean marine taxa. Indeed, the genus is completely stygobiont and does not occur in fluvial environments. The Pyrenees represent a watershed boundary that eliminates the possibility of the derivation of one species from the other by active dispersal after establishment in continental waters. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 387–414. 相似文献
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BONAVENTURE SONKÉ CHARLEMAGNE NGUEMBOU K. AARON P. DAVIS 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(3):425-430
A distinctive new species of dwarf monocaulous Coffea (Rubiaceae) from Cameroon is described and illustrated. Coffea mapiana is the second dwarf monocaulous known from Cameroon. Its diagnostic characters are elucidated and its taxonomic affinities are discussed; a conservation assessment is provided. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 425–430. 相似文献
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The origin and genetic relationships of the Baikal seal, Phoca sibirica, by restriction analysis of mitochondrial DNA 总被引:1,自引:0,他引:1
The origin and genetic relationships of the Baikal seal, Phoca sibirica, were studied by restriction fragment length polymorphism analysis of mitochondrial DNA (mtDNA). Using 17 different six-base recognition restriction endonucleases, we examined 98 Baikal seals, and two other related species, the ringed seal, P. hispida, (n=87), and the Caspian seal, P. caspica, (n=94). Analysis revealed the existence of 87 mtDNA haplotypes in the total of 279 specimens. The haplotypes of each species were divided into different clusters on a dendrogram obtained by UPGMA based on haplotype frequency and mtDNA base substitution. No common haplotypes were found among the species examined. The Baikal seal is much more closely related to the ringed seal than the Caspian seal. The amount of divergence suggested that an ancestor of the Baikal seal came down to the lake approximately 0.4 million years ago as was previously indicated by paleontological studies. The seals examined here showed lower variabilities. 相似文献
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QIONG YUAN QIN-ER YANG 《Botanical journal of the Linnean Society. Linnean Society of London》2006,150(3):343-353
Chromosome numbers and morphology in 22 populations belonging to 11 taxa of Aconitum subgenus Lycoctonum (Ranunculaceae) from China were studied. Some taxa were diploid, with 2 n = 16, but four species and two varieties were found to be tetraploid, with 2 n = 32. They are concentrated in the Hengduan Mountains region in south-west China, indicating that polyploidy could have played an important role in the speciation of the subgenus in this region, one of the areas of the world with a high concentration of endemic species. The relationships of some of the species are discussed. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 343–353. 相似文献
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DANIELA MILANO DANIEL E. RUZZANTE VICTOR E. CUSSAC PATRICIO J. MACCHI RICARDO A. FERRIZ JUAN P. BARRIGA JUANA C. AIGO MARIA E. LATTUCA SANDRA J. WALDE 《Biological journal of the Linnean Society. Linnean Society of London》2006,87(1):69-82
We examined the morphological variability (23 morphometric traits) among individual Galaxias platei ( N = 380) collected from 20 postglacial lakes in the southern Andes. The lakes were chosen to cover the latitudinal range of the species in Patagonia. Diet examined for a subset of these fish ( N = 261) collected during the summer months (January through March), differed among river basins but there were no clear latitudinal trends in the consumption of any prey type. Diet may, however, have partially shaped morphology, as pelvic measures were negatively correlated with consumption of amphipods. Substantial differentiation among populations was observed, primarily in the shape and dimensions of the head, in caudal morphology and in fin length. Our results indicate that the morphology of G. platei varies with latitude, and may be related to risk of predation and diet. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 69–82. 相似文献
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Alicia M. Hendrix Kathi A. Lefebvre Lori Quakenbush Anna Bryan Raphaela Stimmelmayr Gay Sheffield Gabriel Wisswaesser Maryjean L. Willis Emily K. Bowers Preston Kendrick Elizabeth Frame Thomas Burbacher David J. Marcinek 《Marine Mammal Science》2021,37(4):1292-1308
Domoic acid (DA) and saxitoxin (STX)-producing algae are present in Alaskan seas, presenting exposure risks to marine mammals that may be increasing due to climate change. To investigate potential increases in exposure risks to four pagophilic ice seal species (Erignathus barbatus, bearded seals; Pusa hispida, ringed seals; Phoca largha, spotted seals; and Histriophoca fasciata, ribbon seals), this study analyzed samples from 998 seals harvested for subsistence purposes in western and northern Alaska during 2005–2019 for DA and STX. Both toxins were detected in bearded, ringed, and spotted seals, though no clinical signs of acute neurotoxicity were reported in harvested seals. Bearded seals had the highest prevalence of each toxin, followed by ringed seals. Bearded seal stomach content samples from the Bering Sea showed a significant increase in DA prevalence with time (logistic regression, p = .004). These findings are consistent with predicted northward expansion of DA-producing algae. A comparison of paired samples taken from the stomachs and colons of 15 seals found that colon content consistently had higher concentrations of both toxins. Collectively, these results suggest that ice seals, particularly bearded seals (benthic foraging specialists), are suitable sentinels for monitoring HAB prevalence in the Pacific Arctic and subarctic. 相似文献
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VLADIMIR VLADIMIROV ZBIGNIEW SZELG 《Botanical journal of the Linnean Society. Linnean Society of London》2006,150(2):261-265
Hieracium petrovae Vladimirov & Szeląg sp. nov. , a new diploid (2 n = 18) species in H. sect. Pannosa Zahn, is described and illustrated from the Rhodope Mountains, South Bulgaria, and compared with related taxa. It grows in relict habitats in crevices of limestone rock together with many Balkan endemics. H. petrovae is morphologically similar to taxa from the H. pannosum , H. pilosissimum and H. heldreichii groups (collective species sensu Zahn) to some of which it is a presumed ancestral species. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 261–265. 相似文献
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ZEKI AYTAÇ BIRGIT NORDT GERALD PAROLLY 《Botanical journal of the Linnean Society. Linnean Society of London》2006,150(3):409-416
Noccaea camlikensis sp. nov. (Brassicaceae) is described and illustrated from a localized serpentine range in southern Turkey. Its close relationship to N. cariensis , from which it differs in leaf and carpological characters, is discussed. The protologue of this fairly unknown species can now be amended to cover better the morphological variability of this taxon. A comparative study of seed-coat anatomy advocates its move from Thlaspi to Noccaea ; the relevant combination N. cariensis (Carlström) Parolly, Nordt & Aytaç is made. The ecology of both vicarious species is discussed and their distribution mapped. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 409–416. 相似文献
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KATJA PUSCH BERNHARD SEIFERT SUSANNE FOITZIK JÜRGEN HEINZE 《Biological journal of the Linnean Society. Linnean Society of London》2006,88(2):223-234
The two sibling ant species Temnothorax nylanderi and Temnothorax crassispinus are widely distributed throughout deciduous forests in Europe. Their resemblance in morphology and similar ecological requirements suggest that they evolved from the same ancestral species in different glacial refugia and re-immigrated into Central Europe after the last ice age. Here, we show that the two species are parapatrically distributed in south-eastern Germany and hybridize along a narrow contact zone close to the continental divide. Phylogeographical data based on the mitochondrial genes cytochrome oxidase subunit I and cytochrome b suggest that the dominant haplotypes for T. nylanderi and T. crassispinus might have diverged already 1.5–2 Mya. Intraspecific variability is extremely low in both species, which might be explained by severe bottlenecks during rapid postglacial expansion into Central Europe. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 223–234. 相似文献
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The genus Borassus (Arecaceae) in West Africa, with a description of a new species from Burkina Faso
ROSS P. BAYTON AMADÉ OUÉDRAOGO SITA GUINKO 《Botanical journal of the Linnean Society. Linnean Society of London》2006,150(4):419-427
Borassus akeassii Bayton, Ouédraogo & Guinko sp. nov. (Arecaceae) is described as a new species from western Burkina Faso in West Africa. It has been confused with the widely distributed African species B. aethiopum and more recently with the Asian B. flabellifer . However, it is distinguished by its glaucous, green leaves with weakly armed petioles and a characteristic pattern of lamina venation. The fruits have a pointed apex and are greenish when ripe, and the flowers of the pistillate inflorescence are arranged in three spirals. The pollen has a reticulate tectum and distinctive ornamentation. The distribution of B. akeassii is discussed and the status of the varieties of Borassus aethiopum (var. bagamojensis and var. senegalensis ) is examined. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 419–427. 相似文献
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MANUEL DE LA ESTRELLA FRANCISCO J. CABEZAS CARLOS AEDO MAURICIO VELAYOS 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(4):541-562
This study provides a checklist of the Caesalpinioideae (Leguminosae) present in Equatorial Guinea, comprising 52 genera and 124 taxa. Seven species are known from Annobón, 33 from Bioko and 109 from Río Muni. The best represented genus is Senna with eight species. In addition, bibliographic references for Caesalpinioideae (Leguminosae) from Equatorial Guinea have been gathered and checked. Fourteen species are included based on literature records, because their distribution ranges suggest they may occur in Equatorial Guinea, 11 introduced species could be naturalized, and 45 taxa are recorded for the first time from the country. This represents an increase of over 35% in the floristic knowledge of Caesalpinioideae from Equatorial Guinea. A statistical summary is presented at the end of the checklist. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 541–562. 相似文献
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RUI JIANG WANG† RICHARD M. K. SAUNDERS 《Botanical journal of the Linnean Society. Linnean Society of London》2006,152(4):513-532
A revised classification of the species of Cyathocalyx (Annonaceae) occurring in western Malesia (Peninsular Malaysia, Sumatra, and Borneo) is presented, with distribution maps. Fifteen species are recognized, including two that are newly described from Borneo ( C. angustipetalus and C. magnifructus ), which are illustrated. Several important nomenclatural changes are validated, including the elevation of Drepananthus carinatus var. deltoideus to specific rank as C. deltoideus , and the transfer of the name Parartabotrys hexagynus to Cyathocalyx as C. hexagynus . Other notable nomenclatural changes include the reduction of the name C. scortechinii to synonymy with C. pubescens . © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 513–532. 相似文献
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XIAO-YUAN HE SHI-JUN WANG JASON HILTON fls YI-LONG ZHOU 《Botanical journal of the Linnean Society. Linnean Society of London》2006,151(2):279-288
Several isolated marattialean synangia and sporangia are reported from coal balls collected from Coal Seam No.1 (C605) in the uppermost Permian Wangjiazhai Formation in Guizhou Province, south-western China. The synangia are radially symmetrical with diameters between 0.8 and 1.2 mm and are 1.7 mm long, consisting of 3–4 elongate sporangia that are fused basally, free distally and possess a pointed apex. The outer-facing sporangial wall is 4–5 cells thick and conspicuously differentiated. Spores are trilete, have a granular ornamentation and are nearly round equatorially with a diameter of 55–60 µm. Comparisons with other anatomically preserved Palaeozoic marattialean synangia from the Euramerican and Cathaysian floras permit their assignment to the genus of Scolecopteris (Zenker) Millay. In this species the thick, outer-facing sporangial walls and large trilete spores are features consistent with those of the Oliveri Group within Scolecopteris , a group that has previously been considered primitive within this genus. Distinctions from all other previously recognized species within the Oliveri Group lead to the creation of a new species, S. guizhouensis sp. nov. This species is the youngest of the reported species of Scolecopteris recognized from the Euramerican and Cathaysian floras, and provides important evidence on the organization of marattialean ferns from the Upper Permian strata of south China. © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 279–288. 相似文献
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