Heterodera longicolla,n. sp. (Nematoda: Heteroderidae) from Buffalo-grass (Buchlo? dactyloides) in Kansas

Heterodera longicolla n. sp., a member of the H. goettingiana group, is described and illustrated from roots of buffalo-grass, Buchloë dactyloides (Nutt.) Engelm., in Manhattan, Kansas. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau & Cobb, 1962, but differs particularly in having a shorter stylet in larvae, males and females; in possessing only three annules on the head of larvae and males; in having a shorter tail in larvae; and by the presence on cysts of a small anus without a circum-anal pattern.     

Heterodera achilleae n. sp. (Nematoda: Heteroderidae) from Yarrow in Yugoslavia

Heterodera achilleae n. sp., a member of the H. rostochiensis group, is described and illustrated from roots of yarrow, Achillea millefolium L. in Sarajevo, Yugoslavia. This new, round-cyst species differs from closely related species especially as follows: (1) from H. leptonepia, by having stouter larvae (a = 21), with longer styler (25 μ), and with outlet of dorsal esophageal gland averaging 5.7 μ from base o f styler; (2) from H. millefolii, in having excretory pore at base of neck and small, straight vulval slit of 5 μ; (3) from H. rostochiensis, in having a B/A ratio (Granek''s ratio) of 1.6 ; (4) from H. tabacum, by longer female stylet, two annules on female head, and males with outlet of dorsal esophageal gland further back (5.7 μ). In addition, H. achilleae n. sp. differs from the latter three species in having prominent longitudinal striae on the anterior half, or more, of cysts and females.     

Heterodera raskii n. sp. (Heteroderidae: Tylenchina), a Cyst Nematode on Grass, from Hyderabad,India

Heterodera raskii n. sp. is described and illustrated from specimens collected from roots of bulb grass, Cyperus bulbosus, in Hyderabad, India. The new species belongs to the ''goettingiana'' group and differs from closely related H. cyperi by the elongate ovoid shaped cysts and females, greater fenestral length, width, vulval slit, and absence of egg sac. The stylet knob shape was round in second-stage juveniles and posteriorly sloping in females and males of H. raskii n. sp., while it was anteriorly directed in second-stage juveniles and spherical in females and males of H. cyperi.     

Four new species of the genus Hymenoscyphus (fungi) based on morphology and molecular data

Four new species of Hymenoscyphus (H. brevicellulus, H. hyaloexcipulus, H. microcaudatus, and H. subsymmetricus) and a new Chinese record (H. subpallescens) are described. These five species share common characteristics: small apothecia (<3mm in diameter); hymenium whitish, pale yellow, to yellow in color; ectal excipulum of textura prismatica; asci arising from simple septa; ascospores scutuloid and guttulate; saprophytic nutrition; and leaf habitats, except for H. subsymmetricus, which grows on herbaceous stems. Phylogenetic analyses of internal transcribed spacer nuclear ribosomal DNA sequences, the universal DNA barcode for fungi, for 16 species in the genus indicated that these taxa were closely related to H. microserotinus, in accordance with their morphological features, but represented independent species. The distinguishing features of each new species from its relatives are discussed, and their phylogenetic relationships explored.     

Arginine vasotocin and androgen pathways are associated with mating system variation in North American cichlid fishes

Neuroendocrine pathways that regulate social behavior are remarkably conserved across divergent taxa. The neuropeptides arginine vasotocin/vasopressin (AVT/AVP) and their receptor V1a mediate aggression, space use, and mating behavior in male vertebrates. The hormone prolactin (PRL) also regulates social behavior across species, most notably paternal behavior. Both hormone systems may be involved in the evolution of monogamous mating systems. We compared AVT, AVT receptor V1a2, PRL, and PRL receptor PRLR1 gene expression in the brains as well as circulating androgen concentrations of free-living reproductively active males of two closely related North American cichlid species, the monogamous Herichthys cyanoguttatus and the polygynous Herichthys minckleyi. We found that H. cyanoguttatus males bond with a single female and together they cooperatively defend a small territory in which they reproduce. In H. minckleyi, a small number of large males defend large territories in which they mate with several females. Levels of V1a2 mRNA were higher in the hypothalamus of H. minckleyi, and PRLR1 expression was higher in the hypothalamus and telencephalon of H. minckleyi. 11-ketotestosterone levels were higher in H. minckleyi, while testosterone levels were higher in H. cyanoguttatus. Our results indicate that a highly active AVT/V1a2 circuit(s) in the brain is associated with space use and social dominance and that pair bonding is mediated either by a different, less active AVT/V1a2 circuit or by another neuroendocrine system.     

The genus Hyalomma Koch, 1844. IX. Redescription of all parasitic stages of H. (Euhyalomma) impeltatum Schulze & Schlottke, 1930 and H. (E.) somalicum Tonelli Rondelli, 1935 (Acari: Ixodidae)

The ticks Hyalomma (Euhyalomma) impeltatum Schulze &; Schlottke, 1930 and H. (E.) somalicum Tonelli Rondelli, 1935 [a species resurrected for “Hyalomma ? species” of Hoogstraal (1956) and H. erythraeum of Kaiser &; Hoogstraal (1968)] are tentatively considered to belong to the H. (E.) asiaticum group of closely related species. Amongst other features that are fairly similar, males of H. impeltatum can be distinguished from those of H. somalicum by the oval posterior margin of the conscutum, a narrow, subtriangular parma, the lack of ventral sclerotised plaques on median, paramedian and 4th festoons, and an incomplete to complete ivory-coloured stripe on the dorsal aspect of the leg segments; whereas males of H. somalicum have a broad but only slightly convex posterior conscutal margin, in most cases no parma, well-developed sclerotised ventral plaques on all festoons, and only a small ivory-coloured spot on the dorsal aspect of the leg segments. Females of H. impeltatum can be distinguished from those of H. somalicum by the bulging rather than flat preatrial fold of the genital aperture. All parasitic stages of both ticks are illustrated and redescribed, and the characteristics that distinguish the adults from those of other closely related species are detailed. Larger domestic and wild ungulates are the principal hosts of the adults of both ticks. Nymphs and larvae of H. impeltatum parasitise rodents, leporids, birds and lizards, whereas the hosts of the immature stages of H. somalicum are unknown. H. impeltatum is widely distributed in Africa north of the equator, Arabia, the Near East and south-western part of Central Asia; in contrast, H. somalicum has a more limited distribution in East Africa and possibly the Arabian Peninsular. Data on their possible disease relationships are also provided.     

A new Habenaria (Orchidaceae) from Belize and Mexico

The new species,Habenaria brownelliana, is described. It is closely related toH. entomantha andH. guadalaharana with regard to overall appearance, and flower size and morphology, but differs from them in its linear-lanceolate leaves, broadly ovate dorsal sepal 6–7 mm wide and longer pedicillate ovary 15–21 mm long.     

New Species of Cyst Nematode Heterodera pakistanensis (Nematoda: Heteroderidae) Attacking Wheat in Pakistan

Heterodera pakistanensis n. sp., described and illustrated from roots of common wheat (Triticum aestivum) from Sukkur, Sind, Pakistan, belongs to the goettingiana group. It is most closely related to H. cyperi Golden, Rau &Cobb, 1962, H. raskii Basnet & Jayaprakash, 1984, and H. mothi Khan &Husain, 1965. Second-stage juveniles (J2) can be distinguished from H. cyperi J2 by an areolated lateral field with four incisures and shorter stylet, whereas cysts are separated by a more elongated vulva slit and the conspicuous structure of the underbridge. It differs from H. raskii by having four areolated lateral lines in J2, smaller female lemon-shaped cyst, shorter fenestra length and width, conspicuous underbridge, and distinct anus with a high cuticular pattern 40-45 μm from posterior end. It also differs from H. mothi by the presence of four areolated lateral lines in J2 and absence of vulva denticles and bullae.     

Delineation of the Species Haemophilus influenzae by Phenotype,Multilocus Sequence Phylogeny,and Detection of Marker Genes

To obtain more information on the much-debated definition of prokaryotic species, we investigated the borders of Haemophilus influenzae by comparative analysis of H. influenzae reference strains with closely related bacteria including strains assigned to Haemophilus haemolyticus, cryptic genospecies biotype IV, and the never formally validated species “Haemophilus intermedius”. Multilocus sequence phylogeny based on six housekeeping genes separated a cluster encompassing the type and the reference strains of H. influenzae from 31 more distantly related strains. Comparison of 16S rRNA gene sequences supported this delineation but was obscured by a conspicuously high number of polymorphic sites in many of the strains that did not belong to the core group of H. influenzae strains. The division was corroborated by the differential presence of genes encoding H. influenzae adhesion and penetration protein, fuculokinase, and Cu,Zn-superoxide dismutase, whereas immunoglobulin A1 protease activity or the presence of the iga gene was of limited discriminatory value. The existence of porphyrin-synthesizing strains (“H. intermedius”) closely related to H. influenzae was confirmed. Several chromosomally encoded hemin biosynthesis genes were identified, and sequence analysis showed these genes to represent an ancestral genotype rather than recent transfers from, e.g., Haemophilus parainfluenzae. Strains previously assigned to H. haemolyticus formed several separate lineages within a distinct but deeply branching cluster, intermingled with strains of “H. intermedius” and cryptic genospecies biotype IV. Although H. influenzae is phenotypically more homogenous than some other Haemophilus species, the genetic diversity and multicluster structure of strains traditionally associated with H. influenzae make it difficult to define the natural borders of that species.Bacterial diversity is usually expected to be organized into phenotypic and genetic clusters recognized as species. The diversity within species is thought to be confined by natural forces, although uncertainty exists as to the nature of the cohesion that constrains this diversity. There is increasing evidence that recombination occurs between distantly related bacteria and that barriers to this process, which could be used to define species naturally, are not always apparent (7, 11). As the bacterial species concept is central to taxonomy and evolutionary biology and has consequences for other disciplines such as the discrimination of pathogens from related bacteria with no pathogenic potential, there is a need to reevaluate to what extent accepted species are indeed coherent units.The gram-negative, nonmotile, facultatively anaerobic bacterium Haemophilus influenzae is a commensal organism of the pharynx frequently involved in localized infections of the respiratory tract, middle ear, and conjunctiva and sometimes in invasive infections such as meningitis or bacteremia. Presumptive identification is based on inability to synthesize NAD (V factor dependence) and porphyrin/hemin (X factor dependence). The latter characteristic is particularly notable as it is shared with few other microorganisms. Further metabolic characteristics of H. influenzae include fermentation of d-xylose, d-ribose, and d-galactose but not sucrose or d-mannose (17). By DNA analysis the X-factor-dependent species H. influenzae, Haemophilus aegyptius, and Haemophilus haemolyticus constitute a closely related group (4, 5, 14, 35), and housekeeping gene nucleotide dissimilarities between these species are exceeded by intraspecific nucleotide dissimilarities within the commensal species Haemophilus parainfluenzae (33).H. aegyptius was conceived as a species distinct from H. influenzae with a particular propensity to cause conjunctivitis (37). However, the existence of H. aegyptius as a separate species is controversial (5), and the designation H. influenzae biogroup aegyptius has been proposed to include traditional H. aegyptius and the closely related clones responsible for the invasive infection known as Brazilian purpuric fever (3), although formally the epithet aegyptius has priority. H. haemolyticus is distinguished from H. influenzae primarily by its hemolytic action on erythrocytes. A recent characterization of a large number of presumptive H. influenzae isolates from the respiratory tract of patients with chronic obstructive airway disease demonstrated that 102 of 258 strains clustered with the type strain of H. haemolyticus by 16S rRNA gene sequence, although many of the isolates were nonhemolytic. In contrast to H. influenzae, the atypical isolates were not associated with exacerbations of the disease (31), emphasizing the need to discriminate between the two species.Genetic methods have identified unnamed taxa of Haemophilus related to H. influenzae. Variant strains isolated from the genitourinary tract were first reported from Canada (1) and have been further studied by Quentin and coworkers (13, 39). These “cryptic genospecies biotype IV” strains (negative for tryptophanase/indole production and positive for urease and ornithine decarboxylase) are distinguishable from typical strains of H. influenzae by multilocus enzyme electrophoresis, 16S rRNA gene sequence, and DNA hybridization. However, only some biotype IV strains belong to the cryptic genospecies, and the lack of phenotypic characters enabling discrimination from H. influenzae has been an obstacle to the formal validation as a species. Another taxon, “Haemophilus intermedius,” was suggested (but never validly published) by Burbach (4). By DNA hybridization and by selected phenotypic traits, these strains take up an intermediate position between H. influenzae and H. parainfluenzae. Two subspecies were described, “Haemophilus intermedius subsp. intermedius,” capable of synthesizing porphyrin from δ-aminolevulinic acid and of fermenting sucrose, and “Haemophilus intermedius subsp. gazogenes,” characterized by the fermentation of mannose and the production of gas from glucose.A number of investigations have addressed the population structure of H. influenzae with assessment of particular virulence traits associated with specific subgroups or clades (9, 26, 32, 41). In the present study we attempted to define the borders of the species by performing phenotypic characterization, 16S rRNA sequence comparison, multilocus housekeeping gene sequence phylogeny, and detection of putative virulence and marker genes on a collection of 42 strains of H. influenzae and representatives of the above-mentioned closely related bacteria.     

Description of a new soldier-fly species of the genus <Emphasis Type="Italic">Adoxomyia</Emphasis> Kertész, 1907 (Diptera,Stratiomyidae), based on adults and larva from Azerbaijan

A new species of the soldier-fly genus Adoxomyia Kertesz, 1907, A. variabilis sp. n., is described from Azerbaijan. The larvae were found in the Astragalus roots damaged by larvae of the buprestid genus Sphenoptera. The adults (males and females) are proved to belong to a species closely related to A. transcaucasica Nartshuk, 2004 but differing in the structure and coloration of the antennae, in the pubescence of the eye of the female, in details of the pubescence of the head in the male, and in the structure of the male genitalia. Differences of the adults and the larva from those of the closely related species are listed.     

<Emphasis Type="Italic">Helicocollum</Emphasis>, a new clavicipitalean genus pathogenic to scale insects (Hemiptera) in Thailand

A new genus pathogenic to scale insects (Coccidae, Hemiptera), Helicocollum, is described from Thailand. It includes the three species, H. chanthaburiensis, H. krabiensis and H. surathaniensis. Phylogenetic inferences on the basis of partial sequences of the large subunit of the nuclear ribosomal DNA, translation elongation factor 1-α and RNA polymerase II subunit 1 place the new genus in the Clavicipitaceae, although morphological features of the phialides resemble Hirsutella in the Ophiocordycipitaceae. Within the Clavicipitaceae, Helicocollum is closely related to Aschersonia, Moelleriella, Regiocrella, and Samuelsia, all known as pathogens of scale insects. Helicocollum differs from other scale insect pathogens in having phialides with helical necks and synnematous or sporodochial conidiomata, but pycnidia. Morphological characteristics are evaluated and compared with other asexual morphs producing twisted, undulated phialidic necks or occurring on scale insects.     

A new species of the chironomid genus <Emphasis Type="Italic">Chaetocladius</Emphasis> (Diptera,Chironomidae) from the Novaya Zemlya Archipelago

The new species Chaetocladius makarchenkovi, subfamily Orthocladinae, is described on the basis of examination of adult males found on the Novaya Zemlya Archipelago (Yuzhnyi Island, Pankov Peninsula, Gribovaya Bay). According to the structure of the head, thorax, and anal point of the hypopygium, the species is closely related to Ch. perennis (Meigen), but differs from it in the form and structure of the lower inner volsella, gonostylus, virga of the hypopygium, in the presence of shortened setae on the antennal flagellum, in the lower antenna index AR, and in the smaller number of Ac and Dc setae on the mesonotum.     

Two new species of the Heterobasidion insulare complex based on morphology and molecular data

Two new species of Heterobasidion, H. amyloideum and H. tibeticum, are described and illustrated from eastern Himalayas. Both species are closely related to the Heterobasidion insulare complex in morphology, but they differ in presence of cystidia and amyloid skeletal hyphae in the context. Phylogenetically, the combined RPB1 and RPB2 sequence data supports H. amyloideum and H. tibeticum as two distinct species within the H. insulare complex.     

Heterakis fieldingi n. sp. (Nematoda: Heterakoidea) from the Australian water-rat, with a review of heterakids occurring in mammals

Heterakis fieldingi n. sp. is described from Hydromys chrysogaster. It can be distinguished from Heterakis spumosa, the species it most closely resembles, in that both males and females are much smaller (4.4 and 5.1 mm, versus 9 and 13 mm, respectively for Australian specimens) and males have shorter tails (178 versus 345 m) with 9 pairs of caudal papillae compared with 10 pairs for H. spumosa. Of the species of Heterakis previously described from mammals three, H. spalacis, H. macrospiculum and H. verrucosa, are presently considered incertae sedis, a fourth has been referred to the genus Gireterakis and a fifth, H. pandei, described almost simultaneously with H. yamaguti, is considered to be synonymous with it. The remaining species are H. spumosa, H. inglisi and H. yamaguti. The presence of these four species in mammalian hosts, when all other representatives of the genus occur in grain-eating birds, cannot be explained at present.     

Description and Larval Heteromorphism of Hoplolaimus concaudajuvencus,n. sp. (Nematoda: Hoplolain-lidae)

Hoplolaimus concaudajuvencus n. sp., of the genus Hoplolaimus Daday, 1905, characterized by larval heteromorphism, is described and illustrated as recovered from ryegrass/bermudagrass golf green turf in Florida. Females and males are closely related to H. galeatus (Cobb, 1913) Thorne, 1935, but have longer stylets with more definitely tulip-shaped stylet knobs which anteriorly tend to close upon the stylet shaft more than in H. galeatus. First and second-stage larvae have a conically-pointed tail unlike any known species of the genus. Subsequent stages, including females, have rounded tails essentially similar to other species of the genus and males possess the typical hopolaimid tail and bursa. The first molt was found to occur within the egg.     

Asymmetric reproductive isolation between two sympatric annual killifish with extremely short lifespans

Background

Interspecific reproductive isolation is typically achieved by a combination of intrinsic and extrinsic barriers. Behavioural isolating barriers between sympatric, closely related species are often of primary importance and frequently aided by extrinsic factors causing spatial and temporal interspecific separation. Study systems with a severely limited role of extrinsic factors on reproductive isolation may provide valuable insights into how reproductive isolation between sympatric species is maintained. We used no-choice experimental set-up to study reproductive barriers between two closely related sympatric African killifish species, Nothobranchius furzeri and Nothobranchius orthonotus. These fish live in small temporary savannah pools and have complete spatial and temporal overlap in reproductive activities and share a similar ecology.

Principal Findings

We found that the two species display largely incomplete and asymmetric reproductive isolation. Mating between N. furzeri males and N. orthonotus females was absent under standard experimental conditions and eggs were not viable when fish were forced to mate in a modified experimental setup. In contrast, male N. orthonotus indiscriminately mated with N. furzeri females, the eggs were viable, and offspring successfully hatched. Most spawnings, however, were achieved by male coercion and egg production and embryo survival were low. Behavioural asymmetry was likely facilitated by mating coercion from larger males of N. orthonotus and at relatively low cost to females. Interestingly, the direction of asymmetry was positively associated with asymmetry in post-mating reproductive barriers.

Significance

We showed that, in fish species with a promiscuous mating system and multiple matings each day, selection for strong mate preferences was relaxed. This effect was likely due to the small proportion of resources allocated to each single mating and the high potential cost to females from mating refusal. We highlight and discuss the fact that males of rarer species may often coercively mate with females of a related, more abundant species.     

On the genus Thaumatoconcha Kornicker and Sohn (Halocyprida) with description of two new species from Southern Ocean deep sea

Two new Thaumatoconcha Kornicker and Sohn, 1976a species, T. dandani n. sp. and T. quasiporosa n. sp., have been described in the present paper. Both species have been collected during two expeditions to the Southern Ocean and are found in the deep sea. The first species is most closely related to T. caraionae Kornicker and Sohn, 1976a, but it has a very specific appearance of copulatory organ, anterior part being covered in small spines. The second species is most closely related to T. porosa Kornicker, 1985, and they differ in the carapace shape and morphology, while they have almost identical appearance of the male copulatory organ. A list of Thaumatocyprididae species and a key to the species of Thaumatoconcha are also presented in this paper.     

Complete Genome Sequence of Macrococcus caseolyticus Strain JSCS5402, Reflecting the Ancestral Genome of the Human-Pathogenic Staphylococci

We isolated the methicillin-resistant Macrococcus caseolyticus strain JCSC5402 from animal meat in a supermarket and determined its whole-genome nucleotide sequence. This is the first report on the genome analysis of a macrococcal species that is evolutionarily closely related to the human pathogens Staphylococcus aureus and Bacillus anthracis. The essential biological pathways of M. caseolyticus are similar to those of staphylococci. However, the species has a small chromosome (2.1 MB) and lacks many sugar and amino acid metabolism pathways and a plethora of virulence genes that are present in S. aureus. On the other hand, M. caseolyticus possesses a series of oxidative phosphorylation machineries that are closely related to those in the family Bacillaceae. We also discovered a probable primordial form of a Macrococcus methicillin resistance gene complex, mecIRA_m, on one of the eight plasmids harbored by the M. caseolyticus strain. This is the first finding of a plasmid-encoding methicillin resistance gene. Macrococcus is considered to reflect the genome of ancestral bacteria before the speciation of staphylococcal species and may be closely associated with the origin of the methicillin resistance gene complex of the notorious human pathogen methicillin-resistant S. aureus.Among various bacterial genera, Macrococcus is the most closely related to the genus Staphylococcus. Historically, it had been included in the staphylococcal family until it was reassigned to an independent genus because of its distinctively smaller genome size than that of staphylococci (19). Currently, seven species are included in genus Macrococcus: Macrococcus bovicus, M. carouselicus, M. caseolyticus, M. equipercicus, M. brunensis, M. hajekii, and M. lamae (26). Unlike staphylococcal species, macrococci do not cause human or animal diseases and are typically isolated from animal skin and food such as milk and meat. The physiological features of this organism are, however, largely unknown, and only a small number of reports on macrococci have been published.M. caseolyticus, previously classified as Staphylococcus caseolyticus (34), was reportedly isolated from cow''s milk, bovine organs and food-processing factories. Phylogenetic relationship analysis based on 16S rRNA sequences revealed that, in addition to Staphylococcus, Bacillus species are also closely related to M. caseolyticus. The morphology of this organism is globular; however, the cell size is larger than for staphylococci.Since the genomes of macrococci are much smaller than those of staphylococci (34), we considered that knowledge of the macrococcal genome would be important in elucidating the evolution of staphylococci along with its acquisition of pathogenic potential to humans. We describe here a unique metabolic feature of M. caseolyticus as inscribed in its genome and the discovery of a primordial form of a mecA gene complex, the causative genetic determinant of the notorious hospital pathogen methicillin-resistant S. aureus (MRSA).     

Complex adaptive traits between mating behaviour and post-copulatory sperm behaviour in squids

Emergence of male dimorphism within a species is the evolutionary process of disruptive selection. In squids, two types of male mating behaviour, known as alternative reproductive tactics (ARTs), are causally associated with adult body size. Males inseminate promiscuously with the same females; large “consort” males internally, and small “sneaker” males externally. Previously we found that in Heterololigo bleekeri, sneaker (but not consort) spermatozoa are able to swarm by sensing self-emitted CO₂. This suggests that a swarming trait might have arisen in sneakers as a “sperm cooperation” strategy among sibling sperm in order to compete with consort males, or as a consequence of adaptation to external fertilization. To address these possibilities, we examined six species where three patterns of insemination are present, namely, only internal, only external, or both ARTs. In three species that employ both ARTs (H. bleekeri, Loligo reynaudii and Uroteuthis edulis), sneaker spermatozoa always exhibited self-swarming capacity. In Idiosepius paradoxus and Todarodes pacificus, which use only external insemination, spermatozoa formed a swarm. However, in Euprymna morsei, which use only internal insemination, sperm were unable to swarm. These results suggest that the self-swarming trait is likely to be linked to the mode of insemination rather than the alternative strategy used by sneaker males. Thus we propose a new hypothesis in which cooperative sperm behaviour has evolved not only through kin selection against sperm competition risks, but also through adaptation to the insemination/fertilization environment.