The taxonomic status of the endangered thin-spined porcupine, Chaetomys subspinosus (Olfers, 1818), based on molecular and karyologic data

Background  

The thin-spined porcupine, also known as the bristle-spined rat, Chaetomys subspinosus (Olfers, 1818), the only member of its genus, figures among Brazilian endangered species. In addition to being threatened, it is poorly known, and even its taxonomic status at the family level has long been controversial. The genus Chaetomys was originally regarded as a porcupine in the family Erethizontidae, but some authors classified it as a spiny-rat in the family Echimyidae. Although the dispute seems to be settled in favor of the erethizontid advocates, further discussion of its affinities should be based on a phylogenetic framework. In the present study, we used nucleotide-sequence data from the complete mitochondrial cytochrome b gene and karyotypic information to address this issue. Our molecular analyses included one individual of Chaetomys subspinosus from the state of Bahia in northeastern Brazil, and other hystricognaths.     

Enamel microstructure ofTribosphenomys (Mammalia,glires): Character analysis and systematic implications

Enamel distribution on the upper and lower incisors ofTribosphenomys minutus (from Late Paleocene-Early Eocene of Inner Mongolia of China) is typically rodent-like, i.e., primarily confined to the anterior surface throughout these transversely compressed, evergrowing teeth. AlthoughTribosphenomys incisor enamel is differentiated into two layers, it does not possess Hunter-Schreger bands (HSB). The incisor and molar enamels are radial in type, a condition regarded as either an autapomorph or a primtive retention forTribosphenomys. Character polarities concerning enamel thickness, enamel layer number, HSB, enamel types, and functional and phylogenetic implications of the enamel structures are discussed. Overall, enamel microstructural evolution at high taxonomic levels within Glires displays considerably more homoplasy than generally appreciated. A phylogenetic definition of Rodentia is proposed.Tribosphenomys is the sister-group of a taxon here named Rodentia, and thus is not itself a member of the order, from a systematic viewpoint.     

Diet of the thin-spined porcupine (Chaetomys subspinosus), an Atlantic forest endemic threatened with extinction in southeastern Brazil

Chaetomys is a poorly known, monotypic genus of tree porcupine threatened with extinction due to deforestation and habitat fragmentation. Its nocturnal habit, relatively restricted distribution and low level of activity have conspired for decades against detailed field studies. Here the diet of the species in restinga forests is described for the first time. Restinga is a subtype of lowland Atlantic forest occurring on sandy soils close to the Atlantic littoral in Brazil. Three radio-collared females were monitored for 12 months between March 2005 and February 2006. Leaves were the most heavily consumed dietary item, varying from 71.9% to 75.4% of the diet of each individual, followed by flowers (7.7% - 15.7%) and fruits (0 - 1.4%). Animals fed on 57 trees from 14 species, with a higher concentration on Pera glabrata (49.8%) and Tapiriria guianensis (22.7%). Pera glabrata is locally abundant and widely distributed in the Atlantic forest. Each individual consumed a smaller subset of plant species (4-10 species/individual) and shared only the two most important tree species (P. glabrata and T. guianensis). Results corroborate previous studies indicating that Chaetomys is a folivore, perhaps the most folivorous amongst the Erethizontidae. Since the most consumed plant species are relatively common and widespread, Chaetomys might thrive in a broader range of habitats than previously suspected, including secondary forests.     

Translocation and long-term monitoring of threatened thin-spined porcupines (Chaetomys subspinosus) on the Brazilian coast

With increasing infrastructural development along Brazil’s coast, environmental regulation measures are becoming increasingly necessary in the face of the damage caused by large projects that impact tropical forests. Brazilian legislation supports implementation of translocation programs for impacted fauna, especially threatened species such as the thin-spined porcupine Chaetomys subspinosus (Rodentia, Erethizontidae). Thus, we present a case study of a pioneer translocation program for the thin-spined porcupine in southeastern Brazil. We aimed to analyze the home-range and habitat selection of three translocated porcupines and one resident individual. In addition, we analyzed the success of the translocations. The porcupines were monitored by radiotelemetry for 3–16 months from October 2015 to March 2017 in a mosaic landscape of restinga forests (sandbank forest vegetation) within a eucalyptus matrix. The translocated porcupines had considerably larger home-ranges (14.29–18.36 ha, minimum convex polygon method – MCP) than did the resident animal (1.22 ha – MCP). We observed stabilization in the home-range size curves of the translocated females in the 7th − 9th month of monitoring. All translocated individuals achieved permanence within a preselected area, indicating adaptation to the new area. In addition, individuals showed a clear preference for restinga forests over drained eucalyptus plantations. Thus, our results demonstrate the feasibility of thin-spined porcupine translocations and the importance of maintaining restinga forest remnants outside of protected areas for the conservation and permanence of viable populations of this rodent.     

Macaca fuscata develops thin enamel on lingual sides of lower incisors

Among the cercopithecids, papionins were believed to have unique lower incisors without enamel on the lingual surfaces based on analyses by light microscopy. We examined unerupted lower permanent incisors ofMacaca fuscata with scanning electron microscopy and found a lingual thin enamel layer. This seems to be the case for all papionins. Thus, all cercopithecines can be regarded to share this trait which distinguishes cercopithecines from colobines who have substantial enamel layer on the lingual sides of lower incisors. Further study will support this hypothesis. This trait produces self-sharpening chisel-like edges on lower incisors. And the adaptive significance of this chisel-like edged incisor could be understood for scraping and cutting to prepare foods for consumption.     

Home range,movements and diurnal roosts of the endangered thin-spined porcupine,Chaetomys subspinosus (Rodentia: Erethizontidae), in the Brazilian Atlantic Forest

Chaetomys subspinosus is the sole species within the Chaetomyinae subfamily of Caviomorph rodents. This poorly studied porcupine is restricted to the Atlantic Forest in eastern Brazil, where deforestation and habitat fragmentation threaten its survival. Data on the ranging and roosting behavior of C. subspinosus is fairly scarce as it is difficult to observe these behaviors in nature and, consequently, it is very rarely detected during field surveys. We monitored the home ranges of three radio-tagged females over the course of 1 year (2005–2006) and collected data on several aspects of their natural history including movement patterns and the use of diurnal roosts and latrines. The animals were monitored at Parque Estadual Paulo Cesar Vinha, a nature reserve dominated by restinga forests, a subtype of Atlantic Forest occurring on sandy soil. The estimated home range varied little between individuals and was relatively small (mean = 2.14 ha/individual and 1.09 ha/individual using minimum convex polygon and kernel methods, respectively). The animals travelled an average of 147 m/night (range: 21–324 m/night) between two consecutive day roosts. The day roosts were mostly located on vine and liana tangles in the canopy which also aid in connecting the canopy to adjacent trees or the forest floor. Latrines were mostly located near the ground in places heavily protected by spiny bromeliads or by other tangled vegetation. Our data suggests that C. subspinosus has the smallest range among all Neotropical Erethizontids which is likely due to its small size and strictly folivorous diet. Our data also helps explain why C. subspinosus is so difficult to observe in nature: researchers should focus on arboreal masses of tangled vegetation where individuals will normally rest during the day.     

Enamel Microstructure of Rodent Molars, Classification, and Parallelisms, with a Note on the Systematic Affiliation of the Enigmatic Eocene Rodent Protoptychus

To investigate the diversity of the enamel structures in rodent molars, the schmelzmuster of more than 270 genera from the various fossil and extant groups was investigated. Only three basic types of schmelzmuster were recognized. The most prominent one, the C-type, is characterized by a basal ring of lamellar enamel (BRLE) surrounding the molars at the base of the crown. It occurs in most murids (cricetids) and other Myodonta. It is shared by the Dipodidea, Eomyidae, Geomyidae, and Gliridae. The C-type schmelzmuster was not found in any of the other rodents groups (Sciuromorpha, Anomaluromorpha, Sciuravida, Hystricognathi, Bathyergomorphi, and Caviida). Despite the rare occurrence of the P-type schmelzmuster with radial enamel only, most of these rodents have thick Hunter–Schreger bands (HSB) in their molars (S-type schmelzmuster). Although the C-type schmelzmuster is strictly limited to the Myomorpha (sensu McKenna and Bell), the fossil record shows that this structure does not form a synapomorphy but developed in parallel mostly from the P-type, but in Gliridae from the S-type schmelzmuster. On the basis of molar and incisor enamel the systematic position of Protoptychus can be evaluated.     

光谱和光强度对棕榈蓟马雌成虫行为反应的影响

室内研究了光谱、光强度对棕榈蓟马雌成虫的趋、避光行为的影响。结果显示:在340—605 nm波谱内棕榈蓟马雌成虫对14个单色光刺激的趋光行为反应为多峰型。其中蓝光483 nm处峰最高,趋光反应率达34.96%,其次为绿光498—524 nm、562—582 nm、紫外光340 nm处;其避光行为反应共有3个峰,其中紫外光380 nm处最高,避光率18.08%,另外2个峰分别在橙光605 nm、紫光420 nm处。在趋光率较高的单色光(340、483、524、582 nm)和避光率较高的单色光(380、605 nm)以及白光刺激下,棕榈蓟马雌成虫的趋光率随光强增强的增强而提高,而避光率则随着光强的增强而降低;光强最弱时仍均有一定趋光率,最强时均未出现高端平台。因此:棕榈蓟马雌成虫对不同单色光具有明显的选择性,光谱和光强度对其趋光行为和避光行为有较大影响,光强度的影响作用与波长因素有关。     

Enamel Structure of Cuvieronius hyodon (Proboscidea, Gomphotheriidae) with a Discussion on Enamel Evolution in Elephantoids

Dental material of the South American elephantoid Cuvieronius hyodon from the Late Pleistocene of the Tarija Basin, Bolivia was sampled for a comprehensive analysis of the microstructure of the enamel. To examine variability at the dentition level, enamel samples of the upper incisor, second deciduous premolar, and molars were sectioned. The incisor and cheek teeth enamel is compared to that of other proboscideans in order to reveal phylogenetically and functional informative features useful to reconstruct the evolution of elephantoid enamel. Studies of the adaptations and evolution of proboscidean enamel have focused so far on molars. Nevertheless, given the possibility of an independent evolution of the enamel at different tooth positions, the variation of the enamel throughout the dentition needs to be taken into consideration when using enamel microstructural characters to infer proboscidean diversity and phylogeny. The results obtained from this study demonstrate the generality, among elephantoids, of the basic microstructural features of Cuvieronius hyodon enamel, allowing the characterization of the Elephantoid Enamel (EE). The differentiation between incisor and molar enamel seen in elephantoids is shown to represent a primitive elephantiform trait, as it also occurs in Phiomia. The three-layered enamel of the cheek teeth appears as the sole synapomorphy of the Elephantoidea, though the character might be homoplastic within the Proboscidea. Characters of the prisms cross-section might be used, on the other hand, to define less inclusive clades within the Elephantoidea.     

Effects of selected botanical insecticides on the behaviour and mortality of the glasshouse whitefly Trialeurodes vaporariorum and the parasitoid Encarsia formosa

Toxicity and behavioural bioassays were used to assess the lethal and sub-lethal effects of two naphthoquinones from the Chilean plant Calceolaria andina L. (Scrophulariaceae), two products derived from Azadirachta indica and pyrethrum on the glasshouse whitefly, Trialeurodes vaporariorum Westwood, and the parasitoid Encarsia formosa Gahan. The potential use of these botanicals in an Integrated Pest Management (IPM) programme is discussed. Pyrethrum was the most toxic botanical tested, but it was toxic to both the whitefly and parasitoid. The naphthoquinones showed potential for inclusion into an IPM programme if, by formulation, the toxicity towards the whitefly could be increased and the deterrent activity towards E. formosa adults decreased. Overall, the A. indica-derived products had the most potential for use in an IPM system for the control of whitefly, which includes E. formosa as a biocontrol agent.     

Incisor Schmelzmuster Diversity in South America's Oldest Rodent Fauna and Early Caviomorph History

Investigation of the enamel microstructure of 20 isolated rodent incisors from the ?Eocene Santa Rosa local fauna (Peru) yielded exclusively schmelzmuster with multiserial Hunter–Schreger bands (HSB). All three subtypes of multiserialHSB with parallel, acute angular, and rectangular interprismatic matrix (IPM) that were previously reported for caviomorph rodents are present. Two lower incisors with rectangular IPM can be attributed to the Octodontoidea, a caviomorph superfamily exhibiting this highly derived enamel type. The plesiomorphic pauciserial condition that characterizes early Paleogene rodents such as North American Ischyromyoidea (including “Franimorpha”) has not been detected. It is therefore probable that the founder populations of South American Caviomorpha already possessed a derived incisor schmelzmuster with multiserial HSB that is shared with African Thryonomyoidea. Because on the North American continent a possible stem-lineage representative of Caviomorpha with multiserial HSB has never been detected, incisor enamel microstructure supports the hypothesis of an African origin of Caviomorpha from a common ancestor shared with Thryonomyoidea.     

Tolerances of Old World bluestems to an acid soil high in exchangeable aluminum

Summary Twenty-nine genotypes of Old World bluestems (Bothriochloa intermedia, B. ischaemum andB. caucasica) were screened for Al tolerance in greenhouse pots of acid Tatum subsoil which was unlimed at pH 4.1 and limed at pH 5.3. Three strains of weeping lovegrass (Eragrostis curvula) and El Reno side-oats grama grass (Bouteloua curtipendula) were also included as indicators of acid and alkaline soil tolerance, respectively. At pH 4.1 only 5 of the 29 bluestems and the 3 weeping lovegrasses produced measurable yields of tops or roots. The remaining 24 bluestems and side-oats grama either died or barely remained alive (due to frequent watering) with no appreciable growth. Weeping lovegrass was significantly more tolerant to the acid soil than any of the bluestems; relative top yields (pH 4.1/pH 5.3) were 101, 94 and 79% for the FQ71, common and FQ22 strains, respectively. Among the 5 bluestems that survived at pH 4.1, relative top yields ranged from 19 to 46%. Bluestems PI 300860 and PI 300857 (bothB. intermedia) appeared more tolerant than PI 300886 (B. intermedia) and PI 312442 (B. caucasica) with PI 300858 (B. intermedia) being intermediate; however, all 5 showed promise for use on acid soils that are high in exchangeable Al. Genotypes that failed to grow at pH 4.1 included members ofB. intermedia, B. ischaemum andB. caucasica. Some of these, such as PI 300825 (B. intermedia) and PI 300765 (B. caucasica), were among the highest yielders at pH 5.3. None of the 10 genotypes ofB. ischaemum survived at pH 4.1.     

Abundance and natural control of the woolly aphid <Emphasis Type="Italic">Eriosoma lanigerum</Emphasis> in an Australian apple orchard IPM program

Woolly aphid (Eriosoma lanigerum Hausmann) (Hemiptera: Aphididae), was monitored over three growing seasons (1995--1998) to assess its abundance and management under apple IPM programs at Bathurst on the Central Tablelands of NSW, Australia. Woolly aphid infestations were found to be extremely low in IPM programs utilising mating disruption and fenoxycarb for codling moth Cydia pomonella L. (Lepidoptera: Tortricidae) control. This was the direct result of increased numbers of natural enemies. No insecticides were applied for woolly aphid control. Under the IPM strategies tested the principal control agent was identified as European earwig (Forficula auricularia L.) (Dermaptera: Forficulidae). Earwigs in combination with Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae) reduced woolly aphid infestations below the action threshold set by commercial growers. However, A. mali together with other flying natural enemies, e.g., ladybirds, lacewings and hoverflies, did not provide commercially acceptable control of woolly aphid in the absence of earwigs. Under the conventional spray program, using the broad-spectrum insecticide azinphos-methyl for codling moth control, the level of woolly aphid infestation increased with each successive season and biological control was not established. When azinphos-methyl was withdrawn, natural enemies migrated in and provided control of woolly aphid within one season. This is the first study to show that the biological control of woolly aphid can be achieved in a commercially viable IPM program.     

Variation of the Schmelzmuster and Other Enamel Characters in Molars of the Primitive Pliocene Vole Ogmodontomys from Kansas

Variation in enamel microhistology (the schmelzmuster) and other features were examined in adult Ogmodontomys poaphagus molars from the Meade Basin of southwestern Kansas. Measurements of total enamel thickness and thickness of tangential enamel were taken on individual triangles of first upper molar samples from the superposed Ripley B, Hornet and Rexroad 2A local faunas. Although thickness of total enamel layers and the tangential zone were not statistically different between triangles and sites, the quality of tangential enamel on the trailing edges increased, from incipient tangential and well-developed tangential enamel (Ripley B and Hornet) to solely well-developed tangential enamel (Rexroad 2A). The fundamental schmelzmuster of O. poaphagus is radial enamel on the leading edges and radial plus incipient or well-developed tangential enamel on the trailing edges. These results support the assertion that the schmelzmuster is a consistent and genetically controlled character mosaic, and confirm suggestions in the literature that Ogmodontomys is distinct from Mimomys. Paired sample Student’s t-tests of trailing/leading edge samples for each triangle were used to test for differentiation. Although the molars of Ogmodontomys poaphagus appear undifferentiated under the light microscope, and are indeed separable from the distinctly negatively differentiated molars of Mimomys by this technique, our results show that the M1s of O. poaphagus are slightly negatively differentiated, with various triangles being either undifferentiated or negatively differentiated. O. sawrockensis has a more primitive schmelzmuster than O. poaphagus, and the presence of discrete (primitive) lamellar enamel on the apices of at least one triangle in 55% of the sample from Fallen Angel B, combined with the absence of lamellar enamel in molars of O. poaphagus from Fox Canyon and all subsequent Ogmodontomys samples, conclusively demonstrates that the Fallen Angel B population of O. sawrockensis was not ancestral to O. poaphagus in the Meade Basin. A unique mosaic of dental and size features indicates that the early Blancan O. pipecreekensis from Indiana is a sister species to O. sawrockensis and not ancestral to O. poaphagus.     

The Enamel Microstructure of the Early Eocene Pantodont Coryphodonand the Nature of the Zigzag Enamel

An additional method for the investigation of the microstructure of enamel is described using the teeth of Coryphodon, Uintatherium, Entelodon, and Crocuta. Under low magnification natural surfaces or sections of teeth display details of the enamel microstructure when the light guide effect of prisms is used. Under the same low magnification even more details were obtained from sputter-coated surfaces of sections. The method is of particular significance for the investigation of large teeth with thick enamels when structures are somewhat irregular. The new method provides a better general survey, where scanning electron microscope images often show confusing details. The enamel of Coryphodon shows oblique lines of nested chevrons that are similar, to some degree, to the zigzag enamel in Crocuta, but a distinct asymmetry between ascending and descending lineaments was observed. This specific Coryphodon -enamel was also found in Uintatherium and Entelodon. This enamel type, which evolved several times in parallel, cannot be attributed to a specific diet, but must be regarded as one of the several ways to strengthen the enamel against breakage.     

Incisor microwear of Sumatran anthropoid primates

Several studies have suggested that incisor microwear reflects diet and feeding adaptations of anthropoids. However, such studies have been largely qualitative, and interpretations have relied on anecdotal references to diet and tooth use reported in the socioecology literature. The current study relates incisor microwear in four anthropoid primates to specific ingestive behaviors and food types. Central incisor casts of wild-shot museum specimens of Hylobates lar, Macaca fascicularis, Pongo pygmaeus, and Presbytis thomasi were examined by scanning electron microscopy, and analyzed using a semiautomated image analysis procedure. Microwear patterns were used to generate predictions regarding diet and anterior tooth use. These predictions were evaluated using data collected during a 1 year study of feeding behavior of these same taxa in the wild (Ungar, 1992, 1994a, b). Results suggest that (1) enamel prism relief is associated with the effectiveness of etching reagents in foods, (2) dental calculus buildup results from a lack of incisor use and perhaps the ingestion of sugar-rich foods, (3) striation density varies with degree of anterior tooth use in the ingestion of abrasive food items, (4) striation breadth is proposed to relate to the ratio of exogenous grit to phytoliths consumed; and (5) preferred striation orientation indicates the direction that food items are pulled across the incisors during ingestion. It is concluded that incisor microwear studies can contribute to the understanding of diets and feeding behaviors of extinct primates. © 1994 Wiley-Liss, Inc.     

Electron probe analysis of maturation ameloblasts of the rat incisor and calf molar

Summary Rapidly frozen upper incisor teeth of rats and molar teeth of calves were freeze fractured, freeze dried and dry dissected in preparation for energy dispersive x-ray emission microanalysis in the scanning electron microscope.Successive zones of ameloblasts adjacent to maturing rat incisor enamel were examined, beginning with cells adjacent to the least mature enamel and progressing to cells over increasingly more mature enamel. Pronounced K _{1, 2}, x-ray peaks were obtained for P, S, Cl, K and Fe but not for Ca. Ca levels were also very low compared with P, S, Cl and K in calf molar maturation ameloblasts, whereas they were high in the distal poles of the secretory odontoblasts in the same specimens.The findings indicate that both intra- and extracellular Ca levels are extremely low in maturation ameloblasts. It is concluded that Ca is neither stored nor concentrated in large amounts by the maturation ameloblasts prior to its entry into the enamel. The suggestion is made that the maturation ameloblasts might regulate entry of calcium into enamel by serving as a selective barrier.     

Sterilization effects of a TiO<Subscript>2</Subscript> photocatalytic film against a<Emphasis Type="Italic">Streptococcus mutans</Emphasis> culture

Streptococcus mutans is one of the more significant pathogens involved in the development of dental caries in humans. The purpose of this research was to design a TiO₂-coated dental instrument and to determine the bactericidal effects of the instrument onS. mutants. TiO₂ photocatalytic films were prepared by the low-pressure metal-organic chemical vapor deposition (LPMOCVD) method using titanium tetraisopropoxide (TTIP) as precursor. The photocatalytic reaction was carried out on a TiO₂-coated pyrex petri dish with an ultraviolet (UV) light emitting diode (LED) illuminator or a fluorescent lamp light source. Our data indicates that the relative survival ratio ofS. mutans when plated onto TiO₂ photocatalytic films and under exposure to UV-A light for 15 min was 0.01%. In addition, a fluorescent lamp light source also had bactericidal effects on theS. mutans plated TiO₂ photocatalytic films. These results indicate that TiO₂-coated dental materials or devices may be useful in dental treatments for the prevention of carious or enamel demineralization.     

Using DNA Barcodes to Identify Road-Killed Animals in Two Atlantic Forest Nature Reserves,Brazil

Road mortality is the leading source of biodiversity loss in the world, especially due to fragmentation of natural habitats and loss of wildlife. The survey of the main species victims of roadkill is of fundamental importance for the better understanding of the problem, being necessary, for this, the correct species identification. The aim of this study was to verify if DNA barcodes can be applied to identify road-killed samples that often cannot be determined morphologically. For this purpose, 222 vertebrate samples were collected in a stretch of the BR-101 highway that crosses two Discovery Coast Atlantic Forest Natural Reserves, the Sooretama Biological Reserve and the Vale Natural Reserve, in Espírito Santo, Brazil. The mitochondrial COI gene was amplified, sequenced and confronted with the BOLD database. It was possible to identify 62.16% of samples, totaling 62 different species, including Pyrrhura cruentata, Chaetomys subspinosus, Puma yagouaroundi and Leopardus wiedii considered Vulnerable in the National Official List of Species of Endangered Wildlife. The most commonly identified animals were a bat (Molossus molossus), an opossum (Didelphis aurita) and a frog (Trachycephalus mesophaeus) species. Only one reptile was identified using the technique, probably due to lack of reference sequences in BOLD. These data may contribute to a better understanding of the impact of roads on species biodiversity loss and to introduce the DNA barcode technique to road ecology scenarios.