Great Intraspecific Variability Research Articles

Morphometrics of the mandible of Metoposaurus krasiejowensis Sulej, 2002 and its ecological implications

Amphibians, due to their ecological plasticity, are some of the best environmental indicators among vertebrates nowadays and in the fossil record. One such example is the extinct family Metoposauridae Watson, 1919. Metoposaurids were abundant amphibians in Late Triassic Pangea. The remains of the genus Metoposaurus Lydekker, 1890 have been found in Germany, Poland and Portugal with three species, respectively Metoposaurus diagnosticus (Meyer, 1842), Metoposaurus krasiejowensis Sulej, 2002 and Metoposaurus algarvensis Brusatte, Butler, Mateus and Steyer, 2015. Since the majority of studies concern the skull and the pectoral girdle, in this work M. krasiejowensis has been analysed through a morphometric study of the mandible. This was made possible by the high abundance of fossils found in Krasiejów (SW Poland) in the last 20 years. The characteristics considered are the morphology of the mandible corpus and its most relevant bones, the adaptation to stress during biting and the dermal ornamentation. The results reveal that not only do these characters have great intraspecific variability, but that at least two groups of a single population of M. krasiejowensis probably had different lifestyles, one more aquatic and the other more terrestrial.

Distinguishing Amazonian ipê species (Handroanthus, Bignoniaceae) using macroscopic wood anatomy and leaf morphology

Summary The ipê trees belonging to the genus Handroanthus are among the most exploited species in the Amazon Forest. However, limitations in the wood identification processes can lead to an overexploitation of a single species. We compare, macroscopically, the wood anatomy of five Amazon Handroanthus species (H. barbatus, H. capitatus, H. impetiginosus, H. incanus and H. serratifolius–Bignoniaceae). Except for H. barbatus the species are trees over 20 m tall and are used commercially. We compared leaf morphology of the two most commercially used species (H. impetiginosus and H. serratifolius), aiming to separate them in the field with identification keys. For wood macroscopical analyses, 55 samples were used; the specimens were obtained in the field and from wood collections. The dichotomous key, preferable to be used in a laboratory, enables the distinction of the five species. However, the use of this key requires more knowledge about wood anatomy, since it was necessary to use more quantitative characteristics, due to the great intraspecific variation in Handroanthus woods, also reflected in the PCA (principal components analysis) and grouping analysis. To identify the plant species H. impetiginosus and H. serratifolius, the use of axial parenchyma type and vessel characteristics were important distinguishing factors, while in leaves, the most significant features were characteristics such as leaf margin, trichomes and domatia. In addition, by focusing on these key features, a multiple access identification key was created, which simplified the identification by reducing the number of characteristics necessary for the identification, facilitating its use in the field.

Applying an internal transcribed spacer as a single molecular marker to differentiate between Tetraselmis and Chlorella species.

In the realm of applied phycology, algal physiology, and biochemistry publications, the absence of proper identification and documentation of microalgae is a common concern. This poses a significant challenge for non-specialists who struggle to identify numerous eukaryotic microalgae. However, a promising solution lies in employing an appropriate DNA barcoding technique and establishing comprehensive databases of reference sequences. To address this issue, we conducted a study focusing on the molecular characterization and strain identification of Tetraselmis and Chlorella species, utilizing the internal transcribed spacer (ITS) barcode approach. By analyzing the full nuclear ITS region through the Sanger sequencing approach, we obtained ITS barcodes that were subsequently compared with other ITS sequences of various Tetraselmis and Chlorella species. To ensure the reliability of our identification procedure, we conducted a meticulous comparison of the DNA alignment, constructed a phylogenetic tree, and determined the percentage of identical nucleotides. The findings of our study reveal the significant value of the ITS genomic region as a tool for distinguishing and identifying morphologically similar chlorophyta. Moreover, our results demonstrate that both the ITS1 and ITS2 regions are capable of effectively discriminating isolates from one another; however, ITS2 is preferred due to its greater intraspecific variation. These results underscore the indispensability of employing ITS barcoding in microalgae identification, highlighting the limitations of relying solely on morphological characterization.

The biology of an isolated Mashona mole-rat population from southern Malawi, with implications for the diversity and biogeography of the genus Fukomys

The Mashona mole-rat, Fukomys darlingi (Thomas, 1895), is a little studied social African mole-rat (Bathyergidae) from south-astern Africa. Here, we present an integrative study characterizing the genetic diversity of populations assigned to F. darlingi with special focus on animals from Nsanje, southern Malawi. These mole-rats show pronounced differences in body mass and general appearance compared to nominate F. darlingi from Zimbabwe and Mozambique, but their taxonomic status has so far remained unclear. A genetic analysis encompassing all major lineages of the genus Fukomys suggests that this population indeed represents a deeply nested lineage within the F. darlingi clade. The karyotype of the Nsanje mole-rats also corresponds to that of the nominate form, being 2n = 54. While both nuclear and mitochondrial data agree about the assignment of the Nsanje mole-rats to F. darlingi, our analyses revealed substantial mitonuclear discordance for other branches within the Fukomys phylogenetic tree. Nsanje mole-rats are significantly larger than nominate F. darlingi and their ontogeny and reproduction closely resemble similar-sized congeneric species rather than the nominate population. The somatic growth of the Nsanje form is the slowest of all African mole-rats. The maximum life span of F. darlingi is at least 19 years. The observed differences between nominate F. darlingi and mole-rats from Nsanje may be attributed mainly to their different body mass. Our study highlights the advantages of an integrative approach for understanding the diversity of African mole-rats and emphasizes the great intraspecific variability that may be encountered in these underground-dwelling rodents.

Cousteaudinium aubryae (Dinophyceae, Cribroperidinioideae) from the lower to middle Miocene of the Pelotas Basin, southern Brazil: Morphology, biochronostratigraphy and paleobiogeography

In this paper, we present a detailed morphological study of Cousteaudinium aubryae (de Verteuil and Norris, 1996) from Miocene deposits of the Pelotas Basin, southern Brazil. C. aubryae is a cyst of an autotrophic dinoflagellate with a great intraspecific morphological variability, evidenced by cavation type and degree, perforations and wall projections. Four morphotypes were identified, which are comparable with specimen records from other continents (e.g. North America and Europe). C. aubryae last occurred in the Pelotas Basin at levels chronocorrelated to the Helicosphaera ampliaperta calcareous nannofossil zone (N-570), suggesting age between Burdigalian and Langhian for the deposits of the Imbé and Cifreira formations. Integration of species records from different latitudes shows a paleobiogeographic distribution pattern predominantly in mid-latitudes, suggesting that C. aubryae was better adapted to non-tropical and no-polar climatic conditions during the early to mid Miocene.

Establishment of mountain birch (Betula pubescens ssp. tortuosa) on a glacial outwash plain: Spatial patterns and decadal processes.

Most of the Earth's surface has now been modified by humans. In many countries, natural and semi‐natural ecosystems mostly occur as islands, isolated by land converted for agriculture and a variety of other land‐uses. In this fragmented state, long‐distance dispersal may be the only option for species to adapt their ranges in response to changing climate. The order of arrival of species may leave a lasting imprint on community assembly. Although mostly studied at and above the species level, such priority effects also apply at the intraspecific level. We suggest that this may be particularly important in subarctic and arctic ecosystems. Mountain birch (Betula pubescens ssp. tortuosa) is characterized by great intraspecific variation. We explored spatio‐temporal patterns of the first two mountain birch generations on a homogeneous, early successional glacial outwash plain in SE Iceland that was the recipient of spatially extensive long‐distance dispersal ca. 30 years ago. We evaluated the decadal progress of the young population by remeasuring in 2018, tree density and growth form, plant size, and reproductive effort on 30 transects (150 m2) established in 2008 at four sites on the plain and two adjacent sites ca. 10 km away. All measured variables showed positive increases, but contrary to our predictions of converging dynamics among sites, they had significantly diverged. Thus, two of the sites (only 500 m apart) could not be distinguished in 2008, but by 2018, one of them had much faster growth rates than the other, a higher growth form index reflecting more upright tree stature, greater reproductive effort, and much greater second‐generation seedling recruitment. We discuss two hypotheses that may explain the diverging dynamics, site‐scale environmental heterogeneity, and legacies of intraspecific priority effects.

Monogeneans from Catfishes in Lake Tanganyika. I: Two new species of Bagrobdella (Dactylogyridae) from Auchenoglanis occidentalis (Siluriformes: Claroteidae)

In the framework of the study of Siluriform fish monogeneans of Lake Tanganyika, we described two new species of Bagrobdella Paperna, 1969 from Auchenoglanis occidentalis (Valenciennes, 1840). Bagrobdella vanhovei sp. nov. is characterized by the morphology of its MCO which is unique among its congeners, presenting a non-terminal opening, whereas the other species have a terminal opening, and Bagrobdella vansteenbergei sp. nov. characterized by the size of its hooks, which are almost all of the same size, and its male copulating organ with a unique shape: a sub-terminal opening and no membrane surrounding. The Multivariate analysis done on morphometrical characters shows that the new and already described species are well individualized, except for Bagrobdella parauchenoglanii Akoumba, Pariselle, Tombi & Bilong Bilong, 2017 and Bagrobdella fraudulenta Euzet & Le Brun, 1990 (but these two species are easily distinguishable by their morphology), and that B. vanhovei sp. nov. has a great intra-specific morphometrical variation.

Intraspecific variation in leaf traits facilitates the occurrence of trees at the Amazonia–Cerrado transition

The ability of plant species to adjust key functional traits through intraspecific variation may determine their success in persisting on our planet in the future, especially in unstable habitats, such as the Amazonia–Cerrado transition zone. We assessed intraspecific variation in 12 leaf morphological and anatomical traits for four tree species along a savanna–forest gradient, including rocky cerrado, typical cerrado and woodland savanna. Generally, all evaluated species showed great intraspecific variation. Our findings demonstrate that trees occurring in the woodland savanna are potentially more vulnerable to climate change, while in the cerrado the individuals presented higher tolerance to water deficit and high temperatures. Trees occurring in open-canopy habitats showed smaller stomata, higher stomata and trichome densities, compared to the same species growing in the woodland savanna. In contrast, the individuals in the woodland savanna shift leaf traits to increase resource acquisition (e.g. light), showing higher specific leaf area and larger stomata, compared to cerrado individuals. We have shown that vegetation-induced shifts in leaf morphological and anatomical traits are a major effect in within-species variability, with consequences for persistence and tolerance of species under future climatic conditions.

AREOLE SPACING AND NUMBERS ON OPUNTIA LITTORALIS CLADODES ARE NOT ASSOCIATED WITH ENVIRONMENTAL CONDITIONS

Opuntia species express great intraspecific morphological variability. All reproductive structures, cladodes (stem segments), and spines respond to macroenvironmental and microenvironmental variation and all of these form from areoles (axillary buds). However, little is known about areole response to light and temperature differences. In this study, I determined whether Opuntia areole numbers and spacing respond to environmental conditions. Terminal cladodes of Opuntia littoralis (Cactaceae) were sampled in Southern California. Data were collected for pad length, pad width, number of areoles on one pad face, number of areoles on the other pad face, and the distances to the nearest areole from the center one on one pad face and on the other for each pad for each of the four orientation groups (N-S, E-W, NW-SE, or NE-SW) for a total of 24 variables. Two-way analysis of variance, related-samples Wilcoxon signed rank tests, and Pearson product-moment correlation identified relationships across and between variables. Results show that areoles are a rather stable feature with regard to environmental variation; there were only small differences on cladode faces oriented in opposite directions. Areoles do not show the more dramatic responses to environmental variation typically seen on the structures borne from those areoles (such as cladodes and spines).

Intraspecific variations in cadmium tolerance and phytoaccumulation in giant duckweed (Spirodela polyrhiza)

Duckweeds are widely recognized for the heavy metal phytoremediation. However, the intraspecific variations in biological responses of duckweeds to heavy metal remain largely unknown. Here, the toxicity and phytoaccumulation of cadmium (Cd) were synchronously evaluated in 30 accessions of giant duckweed (Spirodela polyrhiza) collected from different provenances in Southern China. Exposure to 1 μM Cd decreased relative growth rates of dry weight, fronds number and fronds area, as well as photosynthetic pigment contents, while it increased H2O2 accumulation, lipid peroxidation and activities of anti-oxidant enzymes in the majority of accessions. Cd treatment led to remarkable Cd accumulation but little changes in the starch content in giant duckweed. The biological responses to Cd varied among the accessions. Further correlation analysis indicated that growth traits and Cd concentration were positively correlated with Cd accumulation, while the contents of chlorophyll, H2O2 and MDA were negatively associated with Cd accumulation. Our results proved the great intraspecific variation in Cd tolerance of giant duckweed, suggesting a valuable natural resource for Cd phytoremediation. Moreover, different mechanisms may be exploited by S. polyrhiza for phytoaccumulation, but growth maintenance, Cd uptake and antioxidative enzyme-independent ROS-scavenging under Cd exposure are the common mechanisms contributing to Cd accumulation ability.

Variación intraespecífica de rasgos funcionales de Cedrela odorata L. en la Península de Nicoya, Costa Rica

El cambio climático modificará el régimen hidrológico global a causa de alteraciones en la magnitud de la precipitación y temperatura, y su interacción con las condiciones físicas y de vegetación de cada lugar; esto representa un gran riesgo para la conservación de las especies, ya que implica variaciones en las condiciones que les son cruciales para su desarrollo. En respuesta a los factores abióticos y bióticos del hábitat, las plantas muestran gran variabilidad intraespecífica de rasgos, esta habilidad les permite sobrevivir, crecer y reproducirse en diversos escenarios. Estudiar la variabilidad intraespecífica de caracteres morfológicos conlleva a entender el potencial de respuesta de las especies a factores de alteración, como el cambio climático. El objetivo del presente estudio fue evaluar la variabilidad intraespecífica del área foliar (mm2), el área foliar específica (mm-2 mg), contenido de materia seca foliar (mg-1 g), densidad de madera (g cm-3) y grosor de corteza (cm) de 90 individuos de Cedrela odorata en tres bosques naturales con distintos regímenes de precipitación anual. A partir de la hipótesis de que C. odorata podría modular la magnitud de expresión de los caracteres morfológicos antes mencionados, de acuerdo con las diferentes condiciones de precipitación. Los resultados demostraron que los valores de los atributos funcionales variaron significativamente entre las poblaciones estudiadas; además, se evidenció que el taxón expresó sus rasgos en un eje de especialización adquisitivo-conservativo en el uso de los recursos. La variabilidad intraespecífica de rasgos en C. odorata podría ser un mecanismo de resiliencia ante el cambio climático.

ЧАСТОТА ВСТРЕЧАЕМОСТИ ПОТЕНЦИАЛЬНО ОПАСНЫХ РАС В РЕГИОНАЛЬНЫХ ПОПУЛЯЦИЯХ ZIMOSEPTORIA TRITICI НА ПОСЕВАХ ПШЕНИЦЫ

The causative agent of Septoria leaf spot of wheat - Zimoseptoria tritici is one of the most harmful and common Septoria pathogens in Russia. Its great intraspecific variability provides the potential for selection of races with increased virulence to resistant varieties. The aim of the research was to reveal the frequency of occurrence of potentially dangerous races in the regional Z. tritici populations on wheat. The investigations were conducted from 2003 to 2018 on the basis of All-Russian Research Institute of Phytopathology. 304 monospores isolates from 7 regions of Russia were tested. The analysis of combinations of the interaction cultivar-isolate and of the diversity of morphological types of colonies of the fungus was discovered 260 races. The potential danger of the race was determined by the aggressiveness degree and the virulence genes spectrum. On these characteristic Z. tritici races were divided into 6 groups. The proportion of potentially dangerous races in regional populations ranged from 5.4 to 16.9%. The highest frequency of potentially dangerous races was observed in the North Caucasus and Central-Chernozem regions. The Volga region was the second most likely to detect such races. In other regions, the numbers of such races was 2-3 times lower, and in Siberia were not observed. The races, virulent to effective resistance Stb-genes, were discovered in all regions, except West-Siberian. Their share in populations was 16-28.6%, and they were more common among races with a wide range of virulence genes. These studies have concluded that the greatest probability of occurrence of potentially dangerous races Z. tritici exists in regions where favorable conditions and this species dominate in the Septoria complex. Expansion of the Z. tritici areal due to changing climatic conditions may lead to an increase in the proportion of aggressive and widely virulent races in other regions.

First molecular identification of Euphlyctis ehrenbergii (Anura: Amphibia) inhabiting southwestern Saudi Arabia

The dicroglossid Euphlyctis ehrenbergii inhabiting southwestern Saudi Arabia has been identified morphologically and molecularly in this study. The morphometric measurements and their indices indicate that females are slightly bigger than males in some characters. Approximately 550 nucleotides of 16S rDNA gene were compared to the Yemeni haplotype available in the GenBank database. The phylogenetic inference revealed a strong sister relationship between the two haplotypes [bootstrap = 100% for maximum parsimony (MP), neighbor joining (NJ) and maximum likelihood (ML)]. The intra-specific genetic distance (D = 0.9%) was lower than the observed variation between southern and northern haplotypes of E. cyanophlyctis (D = 4.6%) currently ascribed to distinct lineages. Nonetheless, results suggest great intra-specific variation within E. ehrenbergii, deserving further investigation. The genetic distance between Yemeni and Saudi haplotypes of E. ehrenbergii (D = 0.9%) resembles intra-specific distances between haplotypes of E. cyanophlyctis ascribed to the same cryptic lineages (e.g. as observed within the lineages including haplotypes from southern India and Sri Lanka). More samples and molecular data from both haplotypes are needed to better clarify their phylogenetic relationships. This study adds a clue for forensic herpetology by highlighting the efficiency of 16S rDNA gene in animal barcoding.

Trabecular bone patterning in the hominoid distal femur.

BackgroundIn addition to external bone shape and cortical bone thickness and distribution, the distribution and orientation of internal trabecular bone across individuals and species has yielded important functional information on how bone adapts in response to load. In particular, trabecular bone analysis has played a key role in studies of human and nonhuman primate locomotion and has shown that species with different locomotor repertoires display distinct trabecular architecture in various regions of the skeleton. In this study, we analyse trabecular structure throughout the distal femur of extant hominoids and test for differences due to locomotor loading regime.MethodsMicro-computed tomography scans of Homo sapiens (n = 11), Pan troglodytes (n = 18), Gorilla gorilla (n = 14) and Pongo sp. (n = 7) were used to investigate trabecular structure throughout the distal epiphysis of the femur. We predicted that bone volume fraction (BV/TV) in the medial and lateral condyles in Homo would be distally concentrated and more anisotropic due to a habitual extended knee posture at the point of peak ground reaction force during bipedal locomotion, whereas great apes would show more posteriorly concentrated BV/TV and greater isotropy due to a flexed knee posture and more variable hindlimb use during locomotion.ResultsResults indicate some significant differences between taxa, with the most prominent being higher BV/TV in the posterosuperior region of the condyles in Pan and higher BV/TV and anisotropy in the posteroinferior region in Homo. Furthermore, trabecular number, spacing and thickness differ significantly, mainly separating Gorilla from the other apes.DiscussionThe trabecular architecture of the distal femur holds a functional signal linked to habitual behaviour; however, there was more similarity across taxa and greater intraspecific variability than expected. Specifically, there was a large degree of overlap in trabecular structure across the sample, and Homo was not as distinct as predicted. Nonetheless, this study offers a comparative sample of trabecular structure in the hominoid distal femur and can contribute to future studies of locomotion in extinct taxa.

Captive breeding reveals larval performance and adult body size differences between two geographical populations of the stag beetle Aegus chelifer chelifer (Coleoptera: Lucanidae)

Stag beetles usually have great intraspecific variation in their body sizes, which can be affected by both environmental and genetic factors. However, direct studies on wild-caught specimens may be insufficient to clarify such variation due to the confounding effects of ecological variance in natural habitats. To evaluate this, the stag beetle Aegus chelifer chelifer MacLeay, 1819 was collected from within two localities (Bangkok metropolitan area and Chanthaburi province) in Thailand and then reared under the same condition to investigate the differences in morphological characteristics between the wild-caught and captive-bred beetles and between the two geographical populations. Narrow-sense heritabilities (h2) of the observed traits in adults were not significant. Variation in the body size of captive-bred specimens was less than in the wild-caught specimens and the overlap of the body size variation between the two populations was lower in the captive-bred beetles. The Chanthaburi population had a significantly larger body size than the Bangkok population. Allometric slopes and intercepts were also significantly different between the two geographic populations. Captive-bred larvae showed similar relative growth rates, but male larvae from the Chanthaburi population had a longer feeding period, and so a larger adult body size, than those from the Bangkok population. The differences between the two populations could be explained by adaptation through larval performances and body size in order to respond to their habitats.

Effects of benzo[a]pyrene on the blood and liver of Physalaemus cuvieri and Leptodactylus fuscus (Anura: Leptodactylidae)

Benzo[a]pyrene (BaP) is a bio-accumulative toxic compound found in the atmosphere, water, and soil that may affect the life cycle of amphibians. In this study, a few contamination biomarkers, such as hepatic melanomacrophages (MMs), mast cells, erythrocyte micronuclei (MN) and white blood cells were used to determine how BaP acts in these cells in the anurans Physalaemus cuvieri and Leptodactylus fuscus. Animals of both species were divided into three treatment groups: 1 day, 7 days and 13 days, subcutaneously injected 2 mg/kg BaP diluted in mineral oil and control group with only mineral oil. After 7 days, BaP caused the frequency of MN to increase in both species while reducing melanin area. The micronucleus frequency increased due to the genotoxicity of BaP, while the decreasing melanin area may be related to the inhibition of tyrosinase activity, an enzyme responsible for regulating melanogenesis, decreasing the synthesis of melanin. The mast cell density increased in all groups and in both species as a response to the inflammatory action of BaP. These cells respond to nonspecific inflammatory effects leading, therefore, to this response in all treatments. The percentage of leukocytes remained unchanged probably due to great intraspecific variability. Additionally, the leukocyte profiles of both species were characterized and the differences were attributed to extrinsic factors. In short, BaP can affect the integrity of several organs and tissues, and cell functions leading to the conclusion that this compound is hepatotoxic, genotoxic and immunotoxic for anurans.

Synonymy of Dinoflagellates with basket-like endoskeletons: Monaster, Amphilothus and Achradina (Amphilothales, Dinophyceae)

The basket-like skeleton-bearing dinoflagellates have been divided into three genera: the little-known Monaster as having a skeleton with longitudinal ribs in the epitheca, Amphilothus with a dense and geometric skeletal tessellation in the epitheca, and Achradina with characteristics intermediate between the other two genera. Cells of different sizes and morphologies corresponding to these genera co-occurred within the same samples from the Mediterranean Sea and South Atlantic Ocean. During cell division, a bigger daughter cell kept the endoskeleton, while the smaller daughter cell formed a new skeleton, beginning with the formation of the hypotheca. The different degree of maturation of the skeleton explained the great intraspecific variability in skeletal morphology. These forms share a distinctive crest-like apical structure with several internal radiating slits. These evidences indicate that the genus Monaster corresponds to immature cells with incomplete developed endoskeleton in the epitheca; Amphilothus corresponds to the mature cells with more developed epithecal endoskeleton, while Achradina shows intermediate morphologies and it is the most common form in the plankton samples. The genera Achradina, Amphilothus and Monaster correspond to a single species, with the name Monaster rete having priority.

Systematics of the Ceracis furcifer Species-Group (Coleoptera: Ciidae): The Specialized Consumers of the Blood-Red Bracket Fungus Pycnoporus sanguineus.

The Ceracis furcifer species-group (Coleoptera: Ciidae) originally comprised nine species names: Ceracis cornifer (Mellié, 1849); C. cylindricus (Brèthes, 1922); C. furcifer Mellié, 1849; C. hastifer (Mellié, 1849); C. monocerus Lawrence, 1967; C. ruficornis Pic, 1916; C. simplicicornis (Pic, 1916); C. semipallidus Pic, 1922 and C. unicornis Gorham, 1898. Ceracis semipallidus was synonymised with C. furcifer and then no further changes were made to the composition of the group. Here, we provide a taxonomic revision of the Ceracis furcifer species-group and new data on the geographic distribution and host fungi of the included species. Lectotypes are designated for C. cornifer, C. furcifer, C. hastifer, C. ruficornis, C. semipallidus and C. unicornis. As results we: (i) synonymise C. cylindricus, C. monocerus, C. simplicicornis, C. unicornis with C. cornifer; (ii) confirm the synonymy of C. semipallidus with C. furcifer; (iii) redescribe C. cornifer, C. hastifer, C. furcifer and C. ruficornis; and (iv) provide an identification key for species in the furcifer group. The frontoclypeal horn and body coloration showed great intraspecific variation. We show that species in the furcifer group have distributions wider than previously known and use mainly Pycnoporus sanguineus as host fungus. Species of the furcifer group are the only animals specialized in feeding on basidiomes of P. sanguineus.

Redescription of two species and proposal of a new synonym in the genus Mycotretus Lacordaire, 1842 (Coleoptera: Erotylidae: Tritomini)

Mycotretus Lacordaire, 1842 is a Neotropical genus of beetles, being the second most speciose genus within Erotylidae. The older descriptions of Mycotretus species are anecdotal and none include information on male and female genitalia, which can have great taxonomic value. Our objective in the present work is to redescribe Mycotretus chilensis Crotch, 1876 and Mycotretus trifasciatus Guérin, 1956 providing the first descriptions of their mouthparts, metendosternite, male and female terminalia, as well as new data on their geographic distribution and host fungi. Additionally, the lectotype of M. chilensis is designated and Mycotretus bicinctus Guérin, 1949 is proposed as a new junior synonym of M. chilensis. Both M. chilensis and M. trifasciatus have great intraspecific variation and are sympatric or syntopic in a few localities. We conclude that morphological differences of the penial flagellum and the metendosternite can be used to diagnose species and may also have phylogenetic signal for Mycotretus species. The present work is our first step in an ongoing taxonomic revision of the genus Mycotretus.

Comparative Morphometry of Bactrian Camel and Dromedary

There are two living species of Old World camelids (Camelidae, Artiodactyla): the Bactrian camel (Camelus bactrianus) and the dromedary (Camelus dromedarius). Differences in osteology between them are poorly known, and this lack of knowledge hinders archaeological and paleontological research. Previous comparative studies have focused on subtle qualitative differences, which are subject to great intraspecific variation and interspecific overlap. In this study, we use simple morphometric methods and statistical analyses to compare the skeleton of Old World camels. Over the entire skeleton we were able to find several consistent differences, some univocal and highly diagnostic, others only slightly significant and noticeable only at a population level. Some of the distinctive traits are suggestive of previously unknown biological adaptations. In particular, the cranial anatomy of Bactrian camels shows characters correlated with increased grazing, while its limb muscle attachments may indicate additional need for lateral stability in a heavier animal. The presence and number of humps is reflected in the vertebral column, with several differences that will be helpful in the reconstruction of fossil species.