Putative speciation events in Lamellodiscus (Monogenea: Diplectanidae) assessed by a morphometric approach

In the present study, we used morphometry as a proxy to study the microevolution of generalist Lamellodiscus (Monogenea, Diplectanidae) species, comprising gill parasites of sparid fish. We investigated 147 individuals, belonging to nine described species, regrouped in four morphotypes. Morphometric measurements were taken on sclerotized parts of the attachment organ. The formation of groups on the basis of the global morphometry within a host species, or between several host species, was assessed using both exploratory analyses (principal component analysis and clustering analysis) and statistical tests. We showed that: (1) for three out of four morphotypes, the global morphometry was significantly different according to host species used, and (2) the coexistence of two populations of Lamellodiscus elegans on Diplodus sargus could reflect an ongoing intra‐host speciation event. We suggest that generalist Lamellodiscus are undergoing specialization on their different hosts, which may lead to speciation. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 559–569.     

Morphotype analysis of the sibling vole (Microtus rossiaemeridionalis) casually introduced to the Russian Far East

Here, we present the morphotypic variety of the m1 and M3 teeth diagnostics for the recently formed isolated population of the sibling vole in Far Eastern Russia. In the Far Eastern population, the prevalence of the individuals with m1 with a complicated crown of the forward unpaired loop of the paraconid is characteristic. Namely, m1 in these individuals shows well-expressed sixth exterior and fifth interior salient angles. The structure of the M3 morphotypes is also unique in the sibling voles in Far Eastern Russia. The dominant morphotypes were typica (47 %) and simplex (45 %), whereas the abundance of the duplicata morphotype was 0.08 %. The frequencies of various m1 and M3 morphotypes found in casually introduced sibling voles in the Far East are not typical of any previously studied Microtus rossiaemeridionalis population.     

Grooming as a secondary behavior in the shrimp Macrobrachium rosenbergii (Crustacea,Decapoda, Caridea)

The giant freshwater prawn, Macrobrachium rosenbergii, is a large shrimp extensively used in aquaculture whose grooming behaviors were analyzed in this study. Macrobrachium rosenbergii exhibits three unique male morphotypes that differ in their behavior, morphology and physiology: small-clawed males (SM), orange-clawed males (OC) and blue-clawed males (BC). The largest and most dominant males, BC males, are predicted to have significantly different grooming behaviors compared to females and the other two male morphotypes. These BC males may be too large and bulky to efficiently groom and may dedicate more time to mating and agonistic interactions than grooming behaviors. Observations were conducted to look at the prevalence of grooming behaviors in the absence and presence of conspecifics and to determine if any differences in grooming behavior exist among the sexes and male morphotypes. Significant differences in the grooming behaviors of all individuals (females and male morphotypes) were found. BC males tended to have the highest grooming time budget (percent of time spent grooming) while SM males had a relatively low grooming time budget. The grooming behaviors of the male morphotypes differed, indicating while these males play distinct, separate roles in the social hierarchy, they also have different grooming priorities. The conditions in which Macrobrachium rosenbergii are cultured may result in increased body fouling, which may vary, depending on the grooming efficiencies and priorities of these male morphotypes. Overall, grooming behaviors were found to be a secondary behavior which only occurred when primary behaviors such as mating, feeding or fighting were not present.     

Description and genetic characterisation of Hysterothylacium (Nematoda: Raphidascarididae) larvae parasitic in Australian marine fishes

Nematodes belonging to the genus Hysterothylacium (family Raphidascarididae) infect various species of marine fish in both the larval and adult stages. Humans can be accidentally infected upon eating infected seafood. In spite of their importance, relatively little is known of their occurrence and systematics in Australia. An examination of various species of marine teleosts in Australian waters revealed a high prevalence of Hysterothylacium larval types. In the present study, seven previously undescribed Hysterothylacium larval morphotypes (V to VII and IX to XII) were discovered. In total we found 10 different morphotypes and we genetically characterised nine morphotypes identified. A morphological dichotomous identification key has been established to differentiate these morphotypes. Since some larvae of Hysterothylacium from marine fishes cannot be differentiated morphologically from other nematode larvae, such as Paraheterotyphlum, Heterotyphlum, Iheringascaris and Lapetascaris, the first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA) of these larvae were characterised to confirm their taxonomic status. This genetic characterisation implied that some distinct morphotypes belong to different developmental stages of the same species. In addition, it revealed that some morphotypes can comprise distinct genotypes. No match was found between ITS-1 and ITS-2 sequences obtained from larvae in the present study and those from adults available in the GenBank, highlighting the lack of knowledge on occurrence of adult nematodes infecting Australian fish.     

Molecular identification of a cryptic species in the Amazonian predatory catfish genus Pseudoplatystoma (Bleeker, 1962) from Peru

Pseudoplatystoma species are highly prized South American Pimelodid migratory catfishes. Until recently, their taxonomy was not clearly established, with discrepancies between morphological and molecular analyses. Here, Pseudoplatystoma species from the Peruvian Amazon were characterized at the molecular level from a sample representing the observed range of their color pattern variations in the study area. Analyses were performed using seven microsatellite loci for 103 specimens and, for part of them (52), using sequences of two regions of their mitochondrial genome [Cytochrome Oxidase subunit I (COI) and Control Region (CR)]. Factorial correspondence analysis and assignment tests based on microsatellite polymorphism showed that the specimens originally identified as P. punctifer belonged to two different gene pools highly differentiated from P. tigrinum. Morphological examination identified two different morphotypes (with and without black stripes), suggesting the existence of two distinct taxa within P. punctifer. This result was corroborated by the ML tree based on CR sequences, where all individuals but four clustered in a similar way as in the FCA and Bayesian assignment tests. For these four individuals, mitochondrial introgression or retention of ancestral polymorphism was likely. In contrast, the ML tree based on COI sequences showed that reciprocal monophyly was not yet achieved for this marker for the two P. punctifer taxa. The existence of three sympatric species of Pseudoplatystoma in the Peruvian Amazon is discussed in relation to their molecular characteristics, color patterns and ecology. Evolutionary scenarios regarding their divergence are hypothesized.     

Description of raabeia,synactinomyxon and neoactinomyxum developing stages of myxosporeans (Myxozoa) infecting Isochaetides michaelseni Lastočkin (Tubificidae) in Lake Balaton and Kis-Balaton Water Reservoir,Hungary

Molecular and morphometric investigations were conducted on the actinosporean morphotypes of myxosporeans surveyed in oligochaetes of Lake Balaton and Kis-Balaton Water reservoir. Oligochaetes belonging to the species Isochaetides michaelseni Lasto?kin and Branchiura sowerbyi Beddard as well as to the genera Nais Dujardin, Dero Müller and Aeolosoma Ehrenberg were studied during an 18-month period. Actinosporeans were obtained exclusively from I. michaelseni (7,818 specimens) with very low prevalence (0.01–0.06%). Four new actinosporean morphotypes of the collective groups raabeia (2 types), synactinomyxon (1 type) and neoactinomyxum (1 type) were found and described, including the first synactinomyxon collective group from Hungarian biotopes and a new raabeia morphotype. Except for Synactinomyxon type 1, the 18S rDNA analysis revealed that the spores did not match any myxospore entity found in the GenBank.     

Morphological variation of Keratella cochlearis (Gosse) in Lake Biwa,Japan

The length of the lorica (LL) of Keratella cochlearis cochlearis and of K. cochlearis tecta and the length of posterior spine (PSL) of the latter morphotype were measured in the strongly eutrophic basin and also in the mesotrophic basin of Lake Biwa, Japan, from September to December, 1980. In the population from the mesotrophic basin, the individuals with longer PSL prevail and the tecta forms are extremely rare. The LL values of both morphotypes from one sample do not differ. In December the LL increased to 95 µm in both morphotypes from 80 µm observed in September, while the PSL values decreased abrubtly in both basins in the middle of this period. It is suggested that the observed increase of LL could be related to the thermic factor, i.e. a steady decrease of water temperature, and the changes of PSL are correlated with the increase of nannoplankton and detritus aggregates noted in November. In this month an increase in fecundity and in the total numbers of rotifers took place as well (Hillbricht-Ilkowska, in press).     

Taxonomic Implications of a Field Study of Morphotypes of Hanuman Langurs (<Emphasis Type="Italic">Semnopithecus entellus</Emphasis>) in Peninsular India

The Hanuman langur is one of the most widely distributed and morphologically variable non-human primates in South Asia. Even though it has been extensively studied, the taxonomic status of this species remains unresolved due to incongruence between various classification schemes. This incongruence, we believe, is largely due to the use of plastic morphological characters such as coat color in classification. Additionally these classification schemes were largely based on reanalysis of the same set of museum specimens. To bring greater resolution in Hanuman langur taxonomy we undertook a field survey to study variation in external morphological characters among Hanuman langurs. The primary objective of this study is to ascertain the number of morphologically recognizable units (morphotypes) of Hanuman langur in peninsular India and to compare our field observations with published classification schemes. We typed five color-independent characters for multiple adults from various populations in South India. We used the presence-absence matrix of these characters to derive the pair-wise distance between individuals and used this to construct a neighbor-joining (NJ) tree. The resulting NJ tree retrieved six distinct clusters, which we assigned to different morphotypes. These morphotypes can be identified in the field by using a combination of five diagnostic characters. We determined the approximate distributions of these morphotypes by plotting the sampling locations of each morphotype on a map using GIS software. Our field observations are largely concordant with some of the earliest classification schemes, but are incongruent with recent classification schemes. Based on these results we recommend Hill (Ceylon Journal of Science, Colombo 21:277-305, 1939) and Pocock (Primates and carnivora (in part) (pp. 97–163). London: Taylor and Francis, 1939) classification schemes for future studies on Hanuman langurs.     

Taxonomy of the Solidago virgaurea Group (Asteraceae) in Poland,with Special Reference to Variability along an Altitudinal Gradient

The morphological differentiation and taxonomic treatment of lowland and high-mountain morphotypes within the Solidago virgaurea group are controversial. To clarify the taxonomic status of these taxa, we conducted a morphometric analysis of 1,746 individuals from 80 localities along an altitudinal gradient from the lowlands of northern Poland to the Carpathians and Sudetes of southern Poland. Multivariate morphometric analyses, cluster analyses and principal component analyses, were used to examine the morphological differentiation within the S. virgaurea group in Poland. Canonical discriminant analysis was applied to determine the morphological characters that best discriminate among the taxa. The stability of the high-mountain Solidago minuta morphotype was tested in an experimental field established in lowland Poland; individuals transplanted from various mountain sites were cultivated at this site, and the morphotypes remained stable in terms of their floral and vegetative characters. Multivariate analyses revealed two morphologically distinct taxa in the S. virgaurea group, which correspond to lowland S. virgaurea s. str. and high-mountain S. minuta as recognised in some European floras. The most important morphological characters for distinguishing the taxa are the number of tubular florets per capitulum, inner involucral bract width and involucre height. Vegetative and inflorescence characters appear to have less taxonomic value because they changed continuously with altitude. A key for identifying S. virgaurea and S. minuta in Poland is presented.     

Sexuality and Genetic Identity in the Agaricus Section Arvenses

Twelve wild collections and one commercial strain were used to characterize breeding systems and to develop molecular identities in the Arvenses section of the genus Agaricus, which includes the “horse mushroom” A. arvensis. Two morphotypes were identified based on macro- and micromorphological features. However, not all collections could be delimited by conventional taxonomic characters. Sequencing of the small subunit intergenic spacer (ITS) region (368 to 370 bp) of the rRNA genes clearly resolved the 13 collections into two clusters consistent with the identified morphotypes. Single-spore progenies and mating type testers were established and used to test intra- and interstock compatibility. The two compatibility groups identified were consistent with ITS clusters. Compatibility group I stocks readily interbred within the constraints of a unifactorial heterothallic system with a multiallelic mating type factor. Compatibility group II had a more restricted breeding pattern, and interactions were difficult to predict on the basis of mating type. Morphological data, ITS sequences, and the ability to interbreed suggest that these collections are part of a complex of interrelated species. Single-spore, homokaryotic isolates from both compatibility groups were able to fruit in compost culture, and two of the collections may represent natural homokaryotic fruiting. We conclude that species from the section Arvenses have versatile unifactorial heterothallic life cycles that permit both interbreeding and homokaryotic fruiting.     

Taxonomy and palaeobiology of the Bathonian (Middle Jurassic) tulitid ammonite Morrisiceras

Taxonomic revision of a number of species belonging to the Middle Bathonian tulitid genus Morrisiceras (Morrisiceras Buckman - macroconchs and Holzbergia Torrens - microconchs) from the Polish Jura (south-central Poland) and England, shows that the genus is in fact represented by one, albeit morphologically very plastic (especially macroconchs), species Morrisiceras morrisi (Oppel). In the Polish Jura area, all of the previously described morphotypes of the macroconch, along with its microconch Holzbergia, are characterized by their identical stratigraphic ranges, both being confined to the Middle Bathonian Morrisi Zone. Much smaller microconchs (males) may have attained maturity earlier than their macroconchs (females). Morphologically very plastic macroconchs seem to have attained full maturity at various shell diameters. Such phenomenon is known in recent coleoids and similarly may be the result of changing environmental conditions. Palaeobiogeographically, the main area occupied by the species was confined to the epicratonic seas, which spread across what is now present-day central and North-West Europe, with some occurrences in western Asia (Turkmenistan/Uzbekistan) and sporadic occurrence in a deep-water facies of Apulia (Italy). Taphonomical observations suggest that Morrisiceras shells have not undergone significant post-mortem drifting or transport after deposition. The preservation of some of the Morrisiceras morphotypes, occurring as dorso-ventrally flattened specimens in the host clays, may indicate that they were quickly buried in life position after they have landed on the sea-floor.     

Genetic structure among morphotypes of the endangered Brazilian palm Euterpe edulis Mart (Arecaceae)

Euterpe edulis (Arecaceae) Mart has high ecological and economic importance providing food resources for more than 58 species of birds and 20 species of mammals, including humans. E. edulis is the second most exploited nontimber product from Brazilian Atlantic Forest. Due to overexploitation and destruction of habitats, E. edulis is threatened by extinction. Euterpe edulis populations have large morphological variations, with individuals having green, red, or yellow leaf sheath. However, no study has related phenotypic distinctions between populations and their levels of genetic structure. Thus, this study aimed to evaluate the diversity and genetic structure of different E. edulis morphotypes. We sampled 250 adult individuals in eight populations with the different morphotypes. Using 14 microsatellite markers, we access genetic diversity through population genetic parameters calculated in the GenAlex program and the diveRsity package in R. We used the Wilcoxon test to verify population bottlenecks and the genetic distance of Nei and Bayesian analysis for genetic clusters. The eight populations showed low allele richness, low observed heterozygosity, and high inbreeding values (f). In addition, six of the eight populations experienced genetic bottlenecks, which would partly explain the low genetic diversity in populations. Cluster analysis identified two clusters (K = 2), with green morphotype genetically distinguishing from yellow and red morphotypes. Thus, we show, for the first time, a strong genetic structure among E. edulis morphotypes even for geographically close populations.     

Small theropod teeth from the Upper Jurassic coal mine of Guimarota (Portugal)

Isolated teeth of small theropod dinosaurs from the Upper Jurassic lignite coal mine of Guimarota (near Leiria, Portugal) are described and illustrated. The well known Upper Jurassic theropods from Europe,Archaeopteryx andCompsognathus, are the most common taxa in the Guimarota assemblage. One morphotype is closely related to an allosaurid theropod. Six further morphotypes of theropod teeth are also described, which are closely related to Cretaceous theropods such as dromaeosaurids, troodontids, tyrannosaurids,Richardoestesia andParonychodon. A Late Jurassic origin of these groups of theropods, which is very often postulated, is discussed.     

Comparative analysis of some biochemical parameters of argan pulp morphotypes (<Emphasis Type="Italic">Argania spinosa</Emphasis> (L) Skeels) during maturity and according to the continentality in Essaouira region (Morocco)

Argania spinosa (L.) Skeels is an endemic forest tree for Morocco. The phytochemical compounds evaluation of four different morphotypes of their fruit pulps was investigated. The total content of sugar, protein and phenolic compounds were monitored during three different stages of maturation in the semi-continental (Mejji) and littoral regions (R’zwa). Total sugars, proteins, phenolics increased up to the ripe stage of all argan fruit morphotypes in the two regions. Spherical shape had higher sugar and protein content than other morphotypes. A significant difference (p < 0.05), was demonstrated by Pearson’s test, between the different morphotypes at three stages studied for all the phytochemicals compounds. Likewise, ANOVA test established that the variation of this compounds was influenced by the stage of maturation and/or region of development and/or their interaction according to fruit shape. Results from this study revealed that the increase of these parameters level take place for the most part during the last stages of maturity which synchronize with fruit softening. Furthermore, our results showed information about the richness of argan fruit pulp in carbohydrates compounds and secondary metabolites as the possibility of their contribution in nutritive forage value especially at ripe stage.     

Morphometric analysis of Tremadocian (earliest Ordovician) kirkocystid mitrates (Echinodermata, Stylophora) from the Taebaeksan Basin, Korea

Abundant isolated remains of stylophoran echinoderms (cornutes and mitrates) are reported for the first time in the late Tremadocian (Asaphellus Zone) Tumugol Formation of Korea. Mitrate remains include numerous adorals of Kirkocystidae. Several new important anatomical features have been observed on these adorals, as an internal calcitic layer that is associated to s₂ and possibly also to the palmar complex. This observation suggests that the palmar complex would be present not only in mitrocystitid mitrates, but also in peltocystitids. For the first time, several morphometric analyses have been undertaken based on isolated kirkocystid adorals, so as to explore the morphological diversity displayed by Korean adorals, but also in order to compare their morphology with that of other Gondwanan kirkocystids. Morphometric analyses indicate the occurrence of two contrasted morphologies within Korean adorals (morphotypes A and B), and of three distinct morphologies within European and North African forms (“Anatifopsis”, “Balanocystites”, and “escandei” morphotypes). Comparison of Korean adorals with those from Europe and North Africa shows that: (1) morphotypes B and “Anatifopsis” are equivalent; consequently, the two Korean specimens referred to morphotype B are assigned to the genus Anatifopsis; (2) morphology of most Korean adorals, which belong to morphotype A, is clearly distinct from that of all other described kirkocystids from Europe and North Africa. The small size, juvenile morphology, and great morphological variability observed in the morphotype A of the Korean adorals are suggestive of possible heterochronic processes (peramorphosis).     

Taxonomie der gattungchiropteridium gocht (dinophyceae) im rupelium des mainzer beckens (mitteloligozän,SW-Deutschland)

Five morphotypes of the dinoflagellate cyst genusChiropteridium Gocht from Middle Oligocene sediments in the Mainz Basin (SW-Germany) are described. Two of the morphotypes are grouped with the speciesChiropteridium aspinatum and C.lobospmosum. For another morphotype the new speciesChiropteridium brevifolium is proposed.     

Identity and Ecophysiology of Uncultured Actinobacterial Polyphosphate-Accumulating Organisms in Full-Scale Enhanced Biological Phosphorus Removal Plants

Microautoradiography combined with fluorescence in situ hybridization (MAR-FISH) was used to screen for potential polyphosphate-accumulating organisms (PAO) in a full-scale enhanced biological phosphorus removal (EBPR) plant. The results showed that, in addition to uncultured Rhodocyclus-related PAO, two morphotypes hybridizing with gene probes for the gram-positive Actinobacteria were also actively involved in uptake of orthophosphate (P_i). Clone library analysis and further investigations by MAR-FISH using two new oligonucleotide probes revealed that both morphotypes, cocci in clusters of tetrads and short rods in clumps, were relatively closely related to the genus Tetrasphaera within the family Intrasporangiaceae of the Actinobacteria (93 to 98% similarity in their 16S rRNA genes). FISH analysis of the community biomass in the treatment plant investigated showed that the short rods (targeted by probe Actino-658) were the most abundant (12% of all Bacteria hybridizing with general bacterial probes), while the cocci in tetrads (targeted by probe Actino-221) made up 7%. Both morphotypes took up P_i aerobically only if, in a previous anaerobic phase, they had taken up organic matter from wastewater or a mixture of amino acids. They could not take up short-chain fatty acids (e.g., acetate), glucose, or ethanol under anaerobic or aerobic conditions. The storage compound produced during the anaerobic period was not polyhydroxyalkanoates, as for Rhodocyclus-related PAO, and its identity is still unknown. Growth and uptake of P_i took place in the presence of oxygen and nitrate but not nitrite, indicating a lack of denitrifying ability. A survey of the occurrence of these actinobacterial PAO in 10 full-scale EBPR plants revealed that both morphotypes were widely present, and in several plants more abundant than the Rhodocyclus-related PAO, thus playing a very important role in the EBPR process.