Description of the male of Sclerocypris tuberculata (Methuen, 1910) (Crustacea,Ostracoda, Megalocypridinae)

The male of Sclerocypris tuberculata (Methuen), thus far unknown, is here described. Relying on the morphology of the copulatory appendages and of the prehensile palps, it appears that this taxon belongs to a separate species group, together with S. zelaznyi and perhaps also S. sarsi. There are some interesting sexual dimorphic characters in the valve morphology: males have shorter valves with a dorsal margin which runs nearly parallel to the ventral one (more elongated valves with sloping dorsal margin in females) and there is lobe-like projection of the valve margin on the ventro-caudal corner of the LV in females which is lacking in the male. Furthermore, the female genital region has a very aberrant morphology, and all specimens from the present collection possess the tuberculated and noded valves.     

Species Diversity,Phylogeny and Large Scale Biogeographic Patterns of the Genus Padina (Phaeophyceae,Dictyotales)

The brown algal genus Padina (Dictyotales, Phaeophyceae) is distributed worldwide in tropical and temperate seas. Global species diversity and distribution ranges, however, remain largely unknown. Species‐level diversity was reassessed using DNA‐based, algorithmic species delineation techniques based on cox3 and rbcL sequence data from 221 specimens collected worldwide. This resulted in estimates ranging from 39 to 61 putative species (ESUs), depending on the technique as well as the locus. We discuss the merits, potential pitfalls, and evolutionary and biogeographic significance of algorithmic species delineation. We unveil patterns whereby ESUs are in all but one case restricted to either the Atlantic or Indo‐Pacific Ocean. Within ocean basins we find evidence for the vast majority of ESUs to be confined to a single marine realm. Exceptions, whereby ESUs span up to three realms, are located in the Indo‐Pacific Ocean. Patterns of range‐restricted species likely arise by repeated founder events and subsequent peripatric speciation, hypothesized to dominate speciation mechanisms for coastal marine organisms in the Indo‐Pacific. Using a three‐gene (cox3, psaA and rbcL), relaxed molecular clock phylogenetic analysis we estimated divergence times, providing a historical framework to interpret biogeographic patterns.     

TRIGONOBALANUS (FAGACEAE): TAXONOMIC STATUS AND PHYLOGENETIC RELATIONSHIPS

The fagaceous genus Trigonobalanus as recently treated includes 3 species, two in Malaysia and Southeast Asia and a single species in Colombia, South America. Character analysis suggests that the genus as currently circumscribed is paraphyletic, without synapomorphies to unite the three species. Each of the three species is a morphologically distinct relict of a group that probably was ancestral to the modern genera Quercus and Fagus. Each of the three species also has at least one autapomorphy which is unique within Fagaceae. Analysis of cupule morphology in Fagaceae provides an interpretation of evolution in cupules which differs substantially from Forman's interpretation. We interpret trigonobalanoid cupules as indicative of an ancestral type of inflorescence within Fagaceae. This inflorescence type is a dichasial structure in which the outermost axes are cupular valves, but the degree of branching and subsequent number of fruits are variable. Following this model, a strict relationship exists between valve number and fruit number as seen in cupules of Trigonobalanus (valves = fruits + 1). Fossil evidence is consistent with our interpretation of the phylogenetic position of the trigonobalanoids. We propose to segregate the three species of Trigonobalanus as three monotypic genera; two of these require names which we provide here: Formanodendron and Colombobalanus.     

Two new species of the diatom genusChaetoceros (Bacillariophyta)

Two new planktonic diatom species of the genusChaetoceros are described herein:Ch. octagonus andCh. rectus, from material of Baja California coasts and the Gulf of California, respectively;Ch. rectus was also found in a sample from Australian waters.Ch. octagonus is a robust species, with a characteristic pyramidal valve shape, heavily silicified valves and setae, and one central rimoportula on every valve in the chain; it is compared with related species, which show a similar morphology, especially by electron microscopy. It belongs into subg.Chaetoceros, sect.Borealia. Ch. rectus is placed in subg.Hyalochaete, and provisionally within sect.Anastomosantia. Its major characters are: chains, cells, and setae are delicate and fragile, cells are joined in the chain by a bridge which connects sibling intercalary setae, valves and setae are weakly silicified, and one rimoportula is present on terminal valves only. Comparison is made with another species of the same section.Ch. rectus shows a different manner of chain-forming within the genus than previously described in the literature.     

Fish conservation in the land of steppe and sky: Evolutionarily significant units of threatened salmonid species in Mongolia mirror major river basins

Mongolia's salmonids are suffering extensive population declines; thus, more comprehensive fisheries management and conservation strategies are required. To assist with their development, a better understanding of the genetic structure and diversity of these threatened species would allow a more targeted approach for preserving genetic variation and ultimately improve long‐term species recoveries. It is hypothesized that the unfragmented river basins that have persisted across Mongolia provide unobstructed connectivity for resident salmonid species. Thus, genetic structure is expected to be primarily segregated between major river basins. We tested this hypothesis by investigating the population structure for three salmonid genera (Hucho, Brachymystax and Thymallus) using different genetic markers to identify evolutionarily significant units (ESUs) and priority rivers to focus conservation efforts. Fish were assigned to separate ESUs when the combined evidence of mitochondrial and nuclear data indicated genetic isolation. Hucho taimen exhibited a dichotomous population structure forming two ESUs, with five priority rivers. Within the Brachymystax genus, there were three B. lenokESUs and one B. tumensisESU, along with six priority rivers. While B. tumensiswas confirmed to display divergent mtDNA haplotypes, haplotype sharing between these two congeneric species was also identified. For T. baicalensis,only a single ESU was assigned, with five priority rivers identified plus Lake Hovsgol. Additionally, we confirmed that T. nigrescens from Lake Hovsgol is a synonym of T. baicalensis. Across all species, the most prominent pattern was strong differentiation among major river basins with low differentiation and weak patterns of isolation by distance within river basins, which corroborated our hypothesis of high within‐basin connectivity across Mongolia. This new genetic information provides authorities the opportunity to distribute resources for management between ESUs while assigning additional protection for the more genetically valuable salmonid rivers so that the greatest adaptive potential within each species can be preserved.     

Sense organs on the ovipositor of Macrocentrus cingulum Brischke (Hymenoptera: Braconidae): their probable role in stinging,oviposition and host selection process

Parasitoid wasps from the insect order Hymenoptera can be deployed successfully as biological control agents for a number of pests, and have previously been introduced for the control of corn pest insect species from the Lepidopteran genus Ostrinia. Organs on the ovipositor of parasitoid wasps have mechanical and tactile senses that coordinate the complex movements of egg laying, and the ovipositor of Hymenopteran insects have evolved associated venom glands as part of their stinging defense. The ovipositor of parasitic wasps has evolved an additional function as a piercing organ that is required for the deposition of eggs within suitable host larvae. The morphology and ultrastructure of sense organs on the ovipositor and sheath of Macrocentrus cingulum Brischke (Hymenoptera: Braconidae) are described using scanning and transmission electron microscopy. Three types of sensilla trichodea were shown to be abundant on the outer sheath of the ovipositor, with types II and III being most distal, and the inner surface of the ovipositor covered with microtrichia, more densely near the apex. Sensilla coeloconica are distributed on both ventral and dorsal valves, while campaniform sensilla and secretory pores are only located on the dorsal valve. The olistheter-like interlocking mechanism, as well as the morphology of the ventral and dorsal valve tips and the ventral valve seal may be important in stinging, oviposition and in the host selection process.     

STRUCTURE,LIFE HISTORY AND SYSTEMATICS OF RHOICOSPHENIA (BACILLARIOPHYTA). I. THE VEGETATIVE CELL OF RH. CURVATA1

Rhoicosphenia Grun. has been placed by some authors in the monoraphid group with Achnanthes Bory and Cocconeis Ehrenb., and by others near Gomphonema Ehrenb. In order to clarify the systematic position of the genus, the morphology and anatomy of the vegetative cells of Rh. curvata (Kütz.) Grun. were investigated using light and electron microscopy. The structure and formation of the two types of valve are described, and the heterovalvy shown to be of a different type from that of the monoraphids; on the basis of raphe, valve and girdle structure a close relationship between these and Rhoicosphenia is unlikely. Rhoicosphenia shows many resemblances to Gomphonema but the types of pore occlusion present, coupled with apparently slight differences in the mucilage-secreting structures and the girdle, suggest that classification in the same family is unwise. The cryptic asymmetry of the valves, and in particular of the raphe system, is noted and explained with reference to their formation; with respect to this asymmetry two configurations of the valves can occur (named cis and trans types) and the distribution of these in raphid genera is discussed briefly. In view of the lack of evidence in raphid diatoms supporting a classification of bands into copulae and pleurae, it is recommended that this practice be suspended.     

MOLECULAR AND MORPHOMETRIC DATA PINPOINT SPECIES BOUNDARIES IN HALIMEDA SECTION RHIPSALIS (BRYOPSIDALES,CHLOROPHYTA)1

Molecular systematic studies have changed the face of algal taxonomy. Particularly at the species level, molecular phylogenetic research has revealed the inaccuracy of morphology‐based taxonomy: Cryptic and pseudo‐cryptic species were shown to exist within many morphologically conceived species. This study focused on section Rhipsalis of the green algal genus Halimeda. This section was known to contain cryptic diversity and to comprise species with overlapping morphological boundaries. In the present study, species diversity within the section and identity of individual specimens were assessed using ITS1–5.8S–ITS2 (nrDNA) and rps3 (cpDNA) sequence data. The sequences grouped in a number of clear‐cut genotypic clusters that were considered species. The same specimens were subjected to morphometric analysis of external morphological and anatomical structures. Morphological differences between the genotypic cluster species were assessed using discriminant analysis. It was shown that significant morphological differences exist between genetically delineated species and that allocation of specimens to species on the basis of morphometric variables is nearly perfect. Anatomical characters yielded better results than external morphological characters. Two approaches were offered to allow future morphological identifications: a probabilistic approach based on classification functions of discriminant analyses and the classical approach of an identification key.     

Comparative egg morphology of six Meccus species and Triatoma recurva (Stål, 1868) Hemiptera: Reduviidae

We investigated the morphology and morphometry of eggs from the colonies of the Entomology Laboratory at ENCB‐IPN belonging to six species of the genus Meccus and Triatoma recurva, using both light and scanning electron microscopy. Egg ornamentation is an important parameter to consider in the differentiation of species. Samples were observed under a scanning electron microscope. Measurements of fifty eggs per species included length, width, and opercular diameter, which were used for the morphometric analysis. The results showed that the seven species display a polygonal ornamentation dominated by hexagons; the operculum shows also a polygonal ornamental characteristic in each species. Morphometry provided valuable information for discriminating between closely related species of the genus Meccus and Triatoma recurva, a species akin to this group, thereby facilitating the complete discrimination of these species.     

Morphological phylogeny of <Emphasis Type="Italic">Geusibia</Emphasis> Jordan, 1932 (Siphonaptera: Leptopsyllidae) and the host–parasite relationship with pikas

Thirteen species of fleas of the genus Geusibia Jordan, 1932 were included in a cladistic analysis based on morphological characters. The results support Geusibia as a monophyletic group within Ctenophyllus Wagner, 1927 (sensu lato) and there are five diagnostic characters that distinguish Geusibia from related genera of Ctenophyllus (s. l). There is no evidence to support a subgeneric classification. We propose that G. ochotona Zhan, Cai & Wu, 1997 and G. lacertosa(Smit, 1975) are junior synonyms of G. torosa Jordan, 1932. After a reconciliation analysis, only two co-speciation events were found in the host–parasite association between Geusibia and pikas (Ochotona:Ochotonidae: Lagomorpha). Therefore, there are no co-evolutionary relationships between them, although a high host preference of Geusibiaspp. is recorded. The distribution and host selection of Geusibia, relative to host associations, are also discussed. Although most specimens of Geusibia are found on pikas, the host is not the definitive factor in the distribution of the genus. Some environmental factors and some host behaviors also determine the presence of Geusibia. Therefore, Geusibia is defined as a host-habitat-dependent flea     

Monster or multiplacophoran: A teratological specimen of the chiton Acanthopleura granulata (Mollusca: Polyplacophora) with a valve split into independent and symmetrical halves

Teratological specimens deviate from the conserved form of their species. In doing so, they serve as natural experiments that refine our knowledge of developmental mechanisms and the natural limits of phenotypes. Here, we describe a specimen of the West Indian Fuzzy Chiton Acanthopleura granulata (Gmelin, 1791) with a fifth valve split into two halves. Using micro-CT to non-invasively visualize the external and internal morphology of this specimen, we find that the half valves are symmetrical and independent from each other and from any of the other valves. The presence of girdle-like tissue between the split valves suggests that this shell abnormality arose in early development and was not the product of damage to the adult animal. While the present specimen of A. granulata is clearly abnormal for its species, its split valve may provide some insights into the developmental pathways that would underlie macroevolutionary transitions to multi-plated chiton forms known from the fossil record.     

DIVERSITY AND HOST SPECIFICITY OF AZOLLA CYANOBIONTS1

A unique, hereditary symbiosis exists between the water fern Azolla and cyanobacteria that reside within a cavity in the dorsal leaf‐lobe of the plant. This association has been studied extensively, and questions have frequently been raised regarding the number and diversity of cyanobionts (cyanobacterial symbionts) among the different Azolla strains and species. In this work, denaturating gradient gel electrophoresis (DGGE) and a clone library based on the 16S rRNA gene were used to study the genetic diversity and host specificity of the cyanobionts in 35 Azolla strains covering a wide taxonomic and geographic range. DNA was extracted directly from the cyanobacterial packets, isolated after enzymatic digestion of the Azolla leaves. Our results indicated the existence of different cyanobiont strains among Azolla species, and diversity within a single Azolla species, independent of the geographic origin of the host. Furthermore, the cyanobiont exhibited host‐species specificity and showed most divergence between the two sections of genus Azolla, Azolla and Rhizosperma. These findings are in agreement with the recent redefinition of the taxon Azolla cristata within the section Azolla. With regard to the taxonomic status of the cyanobiont, the genus Anabaena of the Nostocaceae family was identified as the closest relative by this work.     

Taxonomy and paleobiogeographic implication of Glabrobournonia Morris and Skelton (Hippuritida,Radiolitidae) from the Late Cretaceous Yigeziya Formation,southwestern Tarim Basin

A re-examination of the specimens that were identified as Biradiolites minor Pojarkova from the late Campanian to early Maastrichtian middle member of the Yigeziya Formation of southwestern Tarim Basin reveals that they should be assigned to the genus Glabrobournonia Morris and Skelton. Glabrobournonia is a genus of radiolitids characterized by indented radial bands, salient ridges on the shell margins and absence of fine ribs on the surface of the right valve. Apart from southwestern Tarim Basin, Glabrobournonia minor (Pojarkova) has also been recorded from the late Campanian of Fergana and Alai basins. The central Asian, late Campanian to early Maastrichtian G. minor differs from the late Campanian to Maastrichtian, eastern Arabian type species Glabrobournonia arabica Morris and Skelton in the flat left valve and an additional fourth ridge on the junction of the dorsal and posterior sides of the right valve. Biradiolites ingens (Des Moulins) could be the direct ancestor of Glabrobournonia. The paleogeographic distribution of Glabrobournonia suggests that this genus dispersed to central Asia from the late Campanian time, becoming widely distributed in the eastern Tethyan region rather than endemic to eastern Arabia. Correspondingly, specimens belonging to Gyropleura yielded from the same bed as G. minor in southwestern Tarim Basin, are similar to the specimens which were attributed to the eastern Arabian Gyropleura sp.; Campanian to early Maastrichtian Osculigera specimens described from the Yigeziya Formation are comparable with those known from the Campanian–Maastrichtian of Iran, Afghanistan and eastern Arabia. The similarity of the rudist assemblages between central Asia and eastern Arabia suggests a faunal connection and affinity between the north and south margins of the eastern Tethyan realm during Campanian to early Maastrichtian times.     

Evolutionarily significant units of the critically endangered leaf frog Pithecopus ayeaye (Anura,Phyllomedusidae) are not effectively preserved by the Brazilian protected areas network

Protected areas (PAs) are essential for biodiversity conservation, but their coverage is considered inefficient for the preservation of all species. Many species are subdivided into evolutionarily significant units (ESUs) and the effectiveness of PAs in protecting them needs to be investigated. We evaluated the usefulness of the Brazilian PAs network in protecting ESUs of the critically endangered Pithecopus ayeaye through ongoing climate change. This species occurs in a threatened mountaintop ecosystem known as campos rupestres. We used multilocus DNA sequences to delimit geographic clusters, which were further validated as ESUs with a coalescent approach. Ecological niche modeling was used to estimate spatial changes in ESUs’ potential distributions, and a gap analysis was carried out to evaluate the effectiveness of the Brazilian PAs network to protect P. ayeaye in the face of climate changes. We tested the niche overlap between ESUs to gain insights for potential management alternatives for the species. Pithecopus ayeaye contains at least three ESUs isolated in distinct mountain regions, and one of them is not protected by any PA. There are no climatic niche differences between the units, and only 4% of the suitable potential area of the species is protected in present and future projections. The current PAs are not effective in preserving the intraspecific diversity of P. ayeaye in its present and future range distributions. The genetic structure of P. ayeaye could represent a typical pattern in campos rupestres endemics, which should be considered for evaluating its conservation status.     

Integrative taxonomy of Peniculus,Metapeniculus, and Trifur (Siphonostomatoida: Pennellidae), copepod parasites of marine fishes from Chile: species delimitation analyses using DNA barcoding and morphological evidence

Pennellidae is a family of copepod parasites of widely distributed marine fishes. The pennellid species are usually morphologically differentiated by cephalothorax, neck, trunk, and abdomen shape. These characters, however, show high polymorphism and therefore using only this type of data, delimitation at species level of this genus is difficult. In this study, we explored the genetic distances calculated from sequences of a DNA barcoding marker (COI mt) (678 base pairs). We also explored the genetic distances of 25 Peniculus specimens associated within nine marine fish species, four Metapeniculus specimens associated within one marine fish species, and four Trifur specimens associated within one marine fish species. All specimens were collected in Antofagasta Bay, Chile and were calculated from sequences of a DNA barcoding marker (COI mt) (678 base pairs). The genetic distance among the Peniculus specimens was 0.95% from the different host species, the Metapeniculus specimens distance was 0.44% and the Trifur specimens was 2.25%. Genetic difference between Peniculus and Metapeniculus was 17.86% and Peniculus differ from T. tortuosus by 18.16%. We analysed the barcoding gene fragment using Bayesian Inference (BI) for phylogenetic reconstruction using three outgroups. Based on the phylogenetic analysis an ultrametric tree was built and a general mixed Yule-coalescent (bGMYC) model was conducted for species delimitation. Morphometrics analyses were made with Bayesian statistics. Mean and credibility limit (95%) for each parameter was calculated. Results show that based on morphology the individuals collected can be assigned to P. cf. fistula von Nordmann, 1832, Metapeniculus antofagastensis Castro-Romero & Baeza-Kuroki, 1985, and Trifur cf. tortuosus Wilson, 1917. High morphological polymorphism was observed for the lineage of Peniculus associated to several host species of marine fishes. Similar results were obtained for Trifur cf. tortuosus parasites on Chilean marine fishes.     

On the anatomy and zoogeography of Tritoniella belli Eliot, 1907 (Opisthobranchia,Nudibranchia) and the synonymy of T. sinuata Eliot, 1907

Summary Rich material of the genus Tritoniella (Opisthobranchia, Nudibranchia) from the Atlantic sector of the Antarctic Ocean demonstrates that the features of the internal anatomy are fairly constant in contrast to those of the external morphology and the cuticularized structures (radula and jaws). There are specimens intermediate between the two known species of the genus: T. belli Eliot, 1907 and T. sinuata Eliot, 1907. These specimens either show a combination of features characteristic for T. belli and T. sinuata, or of features which lie in between. Therefore T. sinuata is considered to be synonymous with T. belli. The monotypic genus Tritoniella has a circumpolar distribution with an extension of its range to the Subantarctic (South Georgia).     

The diversity of arbuscular mycorrhizas of selected Australian Fabaceae

Abstract

Members of the Australian native perennial Fabaceae have been little explored with regard to their root biology and the role played by arbuscular mycorrhizal (AM) fungi in their establishment, nutrition and long-term health. The ultimate goal of our research is to determine the dependency of native perennial legumes on their co-evolved AM fungi and conversely, the impact of AM fungal species in agricultural fields on the productivity of sown native perennial legume pastures. In this paper we investigate the colonisation morphology in roots and the AMF, identified by spores extracted from rhizosphere soil, from three replicate plots of each of the native legumes, Cullen australasicum, C. tenax and Lotus australis and the exotic legumes L. pedunculatus and Medicago sativa. The plants were grown in an agricultural field. The level and density of colonisation by AM fungi, and the frequency of intraradical and extraradical hyphae, arbuscules, intraradical spores and hyphal coils all differed between host plants and did not consistently differ between native and exotic species. However, there were strong similarities between species in the same genus. The three dominant species of AM fungi in rhizosphere soil also differed with host plant, but one fungus (Glomus mosseae) was always the most dominant. Sub-dominant AM species were the same between species in the same genus. No consistent differences in dominant spores were observed between the exotic and native Fabaceae species. Our results suggest that plant host influences the mycorrhizal community in the rhizosphere soil and that structural and functional differences in the symbiosis may occur at the plant genus level, not the species level or due to provenance.     

Morphological investigations of the frustule, perizonium and initial valves of the freshwater diatom Achnanthes crenulata Grunow (Bacillariophyceae)

The present study clarifies the fine structure of the vegetative frustules, initial valves and perizonium of Achnanthes crenulata Grunow. The valves of the vegetative cell are distinctly linear‐lanceolate with an undulate margin. The valve face is quite flat and in girdle view is smoothly curved as in species of Gephyria (Bacillariophyceae). However, the valve face of the initial cells is slightly rounded and does not have an undulate margin. Furthermore, the rapheless sternum is centrally positioned along the apical axis of the araphid initial valve. As this taxon develops from auxospore to initial valve, it forms only longitudinal perizonial bands; no transverse bands arise. The perizonium consists of three silicified bands: one large, central longitudinal plate and two bands that underlie this plate; these two bands are either open or closed. This taxon has several conspicuous structures compared to other marine species of Achnanthes, but the structure of the perizonium supports the position of A. crenulata within Achnanthes sensu stricto.