Phylogeography and cryptic species structure of a locally adapted parasite in New Zealand.

The phylogeographic patterns of many taxa on New Zealand's South Island are characterized by disjunct distributions that have been attributed to Pleistocene climatic cycles and the formation of the Southern Alps. Pleistocene glaciation has been implicated in shaping the contemporary genetic differentiation between populations of the aquatic snail Potamopyrgus antipodarum. We investigated whether similar phylogeographic patterns exist for the snail's locally adapted trematode parasite, Atriophallophorus winterbourni. We found evidence for a barrier to gene-flow in sympatry between cryptic, but ecologically divergent species. When focusing on the most common of these species, disjunct geographic distributions are found for mitochondrial lineages that diverged during the Pleistocene. The boundary between these distributions is found in the central part of the South Island and is reinforced by low cross-alpine migration. Further support for a vicariant origin of the phylogeographic pattern was found when assessing nuclear multilocus SNP data. Nuclear and mitochondrial population differentiation was concordant in pattern, except for populations in a potential secondary contact zone. Additionally, we found larger than expected differentiation between nuclear- and mitochondrial-based empirical Bayes FST estimates (global FST : 0.02 vs. 0.39 for nuclear and mitochondrial data, respectively). Population subdivision is theoretically expected to be stronger for mitochondrial genomes due to a smaller effective population size, but the strong difference here, together with mitonuclear discordance in a putative contact zone, is potentially indicative of divergent gene flow of nuclear and mitochondrial genomes.

Random Tanglegram Partitions (Random TaPas): An Alexandrian Approach to the Cophylogenetic Gordian Knot.

Symbiosis is a key driver of evolutionary novelty and ecological diversity, but our understanding of how macroevolutionary processes originate extant symbiotic associations is still very incomplete. Cophylogenetic tools are used to assess the congruence between the phylogenies of two groups of organisms related by extant associations. If phylogenetic congruence is higher than expected by chance, we conclude that there is cophylogenetic signal in the system under study. However, how to quantify cophylogenetic signal is still an open issue. We present a novel approach, Random Tanglegram Partitions (Random TaPas) that applies a given global-fit method to random partial tanglegrams of a fixed size to identify the associations, terminals, and nodes that maximize phylogenetic congruence. By means of simulations, we show that the output value produced is inversely proportional to the number and proportion of cospeciation events employed to build simulated tanglegrams. In addition, with time-calibrated trees, Random TaPas can also distinguish cospeciation from pseudocospeciation. Random TaPas can handle large tanglegrams in affordable computational time and incorporates phylogenetic uncertainty in the analyses. We demonstrate its application with two real examples: passerine birds and their feather mites, and orchids and bee pollinators. In both systems, Random TaPas revealed low cophylogenetic signal, but mapping its variation onto the tanglegram pointed to two different coevolutionary processes. We suggest that the recursive partitioning of the tanglegram buffers the effect of phylogenetic nonindependence occurring in current global-fit methods and therefore Random TaPas is more reliable than regular global-fit methods to identify host-symbiont associations that contribute most to cophylogenetic signal. Random TaPas can be implemented in the public-domain statistical software R with scripts provided herein. A User's Guide is also available at GitHub.[Codiversification; coevolution; cophylogenetic signal; Symbiosis.].

Conspecific migration and environmental setting determine parasite infracommunities of non-migratory individual fish.

Parasite infracommunities tend to be stochastic in nature, although environmental characteristics such as the type of water source in streams and host traits can have an effect on the biotic assemblages and by extension the parasite fauna. We examined the effect of water source and the rate of adult fish migration on the metazoan parasite infracommunities of conspecific juvenile brown trout, Salmo trutta L. among streams flowing into Lake Lucerne (Switzerland). Juvenile (1 to 2-year old) fish harboured higher parasite species richness in groundwater-fed than in surface water-fed streams, whereas the rate of fish migration did not affect infracommunity richness. Heteroxenous species were more common in groundwater-fed streams with high and medium rates of trout migration, whereas infracommunities in surface water-fed streams and streams with low rates of fish migration were dominated by one monoxenous parasite or lacked infections. Similarity in the parasite infracommunity composition of juvenile trout across streams was explained by the interaction between type of water source and adult migration rates. Our conclusions support that similarity in the parasite composition of resident freshwater conspecifics can be predicted by the local environmental settings and host migratory behaviour, whereas parasite richness is mainly influenced by the environmental characteristics.

Microphallus ochotensis sp. nov. (Digenea, Microphallidae) and relative merits of two-host microphallid life cycles.

A new digenean species, Microphallus ochotensis sp. nov., was described from the intestine of Pacific eiders (Somateria mollissima v-nigrum) from the north of the Sea of Okhotsk. It differs from other microphallids in the structure of the metraterm, which consists of two distinct parts: a sac with spicule-like structures and a short muscular duct opening into the genital atrium. Mi. ochotensis forms a monophyletic clade together with other congeneric species in phylograms derived from the 28S and ITS2 rRNA gene. Its dixenous life cycle was elucidated with the use of the same molecular markers. Encysted metacercariae infective for birds develop inside sporocysts in the first intermediate host, an intertidal mollusc Falsicingula kurilensis. The morphology of metacercariae and adults was described with an emphasis on the structure of terminal genitalia. Considering that Falsicingula occurs at the Pacific coast of North America and that the Pacific eider is capable of trans-continental flights, the distribution of Mi. ochotensis might span the Pacific coast of Alaska and Canada. The range of its final hosts may presumably include other benthos-feeding marine ducks as well as shorebirds. We suggest that a broad occurrence of two-host life cycles in microphallids is associated with parasitism in birds migrating along sea coasts. The chances that migrating birds would stop at a site where both first and second intermediate hosts occur are relatively low. The presence of a single molluscan host in the life cycle increases the probability of transmission.

Molecular characterisation of four echinostomes (Digenea: Echinostomatidae) from birds in New Zealand, with descriptions of Echinostoma novaezealandense n. sp. and Echinoparyphium poulini n. sp.

Morphological and molecular characterisation of echinostome specimens (Digenea: Echinostomatidae) recovered in one Anas platyrhynchos L. and one Cygnus atratus (Latham) (Anseriformes: Anatidae) from New Zealand revealed the presence of two known species, Echinostoma miyagawai Ishii, 1932 and Echinoparyphium ellisi (Johnston & Simpson, 1944) and two species new to science. Comparative morphological and phylogenetic analyses supported the distinct species status of Echinostoma novaezealandense n. sp. ex Branta canadensis (L.), A. platyrhynchos and C. atratus, and Echinoparyphium poulini n. sp. ex C. atratus. Echinostoma novaezealandense n. sp., a species of the "revolutum" species complex characterised by the possession of a head collar armed with 37 spines, keyed down to E. revolutum but was distinguished from the latter in having a much narrower body with almost parallel margins, longer oesophagus, wider cirrus-sac, larger seminal vesicle, much smaller ventral sucker, ovary, Mehlis' gland and testes, more anteriorly located ovary and testes, and distinctly smaller eggs (81-87 × 42-53 vs 106-136 × 55-70 µm). This new species appears similar to Echinostoma acuticauda Nicoll, 1914 described in Australia but differs in having a longer forebody, more posteriorly located ovary and testes, and much smaller eggs (81-87 × 42-53 vs 112-126 × 63-75 µm). Echinoparyphium poulini n. sp. is differentiated from the four species of Echinoparyphium possessing 37 collar spines considered valid as follows: from E. chinensis Ku, Li & Chu, 1964 in having a much smaller body, four (vs five) angle spines and simple seminal vesicle (vs bipartite); from E. schulzi Matevosyan, 1951 in having a less robust body at a comparable body length, much smaller ventral sucker, ovary and testes, and longer but narrower eggs (87-109 × 50-59 vs 70-85 × 60-84 µm); and from the two smaller forms, E. serratum Howell, 1968 and E. aconiatum Dietz, 1909, in a number of additional metrical features correlated with body size and especially in the possession of much larger collar spines. Partial fragments of the mitochondrial nad1 and 28S rRNA genes were amplified for representative isolates of the four species and analysed together with sequences for Echinostoma spp. and Echinoparyphium spp. available on GenBank. Phylogenetic analyses based on the mitochondrial nad1 gene revealed congruence between the molecular data and species identification/delineation based on morphology; this was corroborated by the 28S rDNA sequence data.

Improving detection of avian malaria from host blood: a step towards a standardised protocol for diagnostics.

Avian malaria, caused by Plasmodium spp., has been linked to the mortality and population-level declines in native birds in some regions. While molecular diagnostic methods have greatly improved our ability to detect infections of both human and bird malaria, failing to identify false negatives remains an important handicap, particularly for avian malaria due to host DNA presence in the bird blood cells. In an attempt to improve the accuracy of diagnostics by PCR, we evaluated the performance of a commercial silica-membrane-based DNA extraction kit by modifying the protocol with four unpooled elution volume alternatives. Our results suggest that the best template is the DNA extract obtained from the second eluate of a first 50 µL elution step. In one case, the only band visible was from this second eluate and, thus, may not have been identified as positive for Plasmodium spp. if a different elution protocol had been followed. Our results are likely explained by the concept of size exclusion chromatography by which particles of different sizes will elute at different rates. Overall, first elution templates may consist of a lower ratio of parasite to host DNA, while second eluates may contain a higher parasite to host DNA ratio. A low ratio of parasite to host DNA is a concern in detecting chronic infections, in which birds typically carry low levels of parasitemia, making accurate diagnostics imperative when identifying reservoirs of disease that could lead to spillback events.

Species of Apatemon Szidat, 1928 and Australapatemon Sudarikov, 1959 (Trematoda: Strigeidae) from New Zealand: linking and characterising life cycle stages with morphology and molecules.

Species of Apatemon Szidat, 1928 and Australapatemon Sudarikov, 1959 are reported from New Zealand for the first time, and their life cycles are resolved using molecular sequence data (28S and ITS rDNA regions and mitochondrial COI). The metacercaria of Apatemon sp. 'jamiesoni' ex Gobiomorphus cotidianus and its cercaria ex Potamopyrgus antipodarum are described in detail. Its adult, found in Anas platyrhynchos and Phalacrocorax punctatus, is identified by molecular sequence data. Apatemon sp. 'jamiesoni' uses a different species of snail host, exhibits consistent differences in the genetic markers examined and its single described adult differs from known species so as to be considered distinct, but its formal description awaits additional adult specimens. Australapatemon niewiadomski n. sp. is described from Anas platyrhynchos. It is distinguished morphologically by the absence of a ringnapf and its overall smaller size compared to most other Australapatemon spp. except Au. magnacetabulum and Au. minor, which are smaller in nearly all features than the new species. Au. niewiadomski n. sp. metacercaria and its intermediate host (Barbronia weberi) are identified via matching of molecular sequence data. The status of Apatemon and Australapatemon as distinct genera is confirmed based on their respective monophyly, and genetic divergence between them is comparable to other well-established genera in the Strigeidae. The diagnosis of Australapatemon is emended. Life history data, accurate patterns of host specialisation and distribution, alongside concurrent molecular and morphological evidence would be useful for an integrative taxonomical approach towards the elucidation of species diversity in this group.

Molecular approaches to trematode systematics: 'best practice' and implications for future study.

To date, morphological analysis has been the cornerstone to trematode systematics. However, since the late-1980s we have seen an increased integration of genetic data to overcome problems encountered when morphological data are considered in isolation. Here, we provide advice regarding the 'best molecular practice' for trematode taxonomy and systematic studies, in an attempt to help unify the field and provide a solid foundation to underpin future work. Emphasis is placed on defining the study goals and recommendations are made regarding sample preservation, extraction methods, and the submission of molecular vouchers. We advocate generating sequence data from all parasite species/host species/geographic location combinations and stress the importance of selecting two independently evolving loci (one ribosomal and one mitochondrial marker). We recommend that loci should be chosen to provide genetic variation suitable to address the question at hand and for which sufficient 'useful' comparative sequence data already exist. Quality control of the molecular data via using proof-reading Taq polymerase, sequencing PCR amplicons using both forward and reverse primers, ensuring that a minimum of 85% overlap exists when constructing consensus sequences, and checking electropherograms by eye is stressed. We advise that all genetic results are best interpreted using a holistic biological approach, which considers morphology, host identity, collection locality, and ecology. Finally, we consider what advances next-generation sequencing holds for trematode taxonomy and systematics.

Two new species of Maritrema Nicoll, 1907 (Digenea: Microphallidae) from New Zealand: morphological and molecular characterisation.

Two new species of the microphallid genus Maritrema (Maritrema) Nicoll, 1907 are described from freshwaters in the South Island of New Zealand. Maritrema deblocki n. sp. occurs as an adult in the mallard Anas platyrhynchos (L.); Maritrema poulini n. sp. is found as sporocysts/cercariae in Potamopyrgus antipodarum (Gray) and as metacercariae in two species of amphipod and two species of isopod. We use morphological and molecular characterisation to distinguish between the two species, and compare them to their four morphologically closest congeners. M. deblocki n. sp. and M. poulini n. sp. are distinguished from each other by the relative sucker size, the positions of the genital pore and ovary, the convergence of the vitelline ribbons, and overall size. With the aid of molecular data, we matched life cycle stages of M. poulini n. sp. and assessed its use of multiple second intermediate hosts. Phylogenetic analyses included sequences for the two new species and the available microphallid sequences for the large ribosomal subunit and the internal transcribed spacer 1 of the ribosomal RNA gene. Closer to each other than to any other species, the sister species together with Maritrema novaezealandense Martorelli, Fredensborg, Mouritsen & Poulin, 2004, Maritrema heardi (Kinsella & Deblock, 1994), Maritrema eroliae Yamaguti, 1939 and Maritrema oocysta (Lebour, 1907) formed a well-supported clade. In addition, we clarify the taxonomic identity of several unidentified Microphallus spp. in the recent ecological literature from New Zealand and propose corrected spellings for a number of Maritrema species epithets.

Four marine digenean parasites of Austrolittorina spp. (Gastropoda: Littorinidae) in New Zealand: morphological and molecular data.

Littorinid snails are one particular group of gastropods identified as important intermediate hosts for a wide range of digenean parasite species, at least throughout the Northern Hemisphere. However nothing is known of trematode species infecting these snails in the Southern Hemisphere. This study is the first attempt at cataloguing the digenean parasites infecting littorinids in New Zealand. Examination of over 5,000 individuals of two species of the genus Austrolittorina Rosewater, A. cincta Quoy & Gaimard and A. antipodum Philippi, from intertidal rocky shores, revealed infections with four digenean species representative of a diverse range of families: Philophthalmidae Looss, 1899, Notocotylidae Lühe, 1909, Renicolidae Dollfus, 1939 and Microphallidae Ward, 1901. This paper provides detailed morphological descriptions of the cercariae and intramolluscan stages of these parasites. Furthermore, partial sequences of the 28S rRNA gene and the mitochondrial gene cytochrome c oxidase subunit 1 (cox1) for varying numbers of isolates of each species were obtained. Phylogenetic analyses were carried out at the superfamily level and along with the morphological data were used to infer the generic affiliation of the species.

Diplostomum von Nordmann, 1832 (Digenea: Diplostomidae) in the sub-Arctic: descriptions of the larval stages of six species discovered recently in Iceland.

Frequent infections with Diplostomum spp. (Digenea: Diplostomidae) were found in the freshwater snail Radix peregra (Müller) and three fish species, the salmonids Salmo trutta fario L., Salvelinus alpinus (L.) and the gasterosteid Gasterosteus aculeatus L., collected in four lakes in south-western Iceland in 2012. Detailed analysis of the isolates integrating molecular, morphological and ecological data revealed that these belong to Diplostomum spathaceum (Rudolphi, 1819) and five putative new species (three infecting both snails and fish). This paper provides detailed descriptions of the metacercariae of the six species-level lineages of Diplostomum spp. and of the cercariae of three of the lineages discovered in Iceland with comments on the application of ITS1 rDNA for species distinction within Diplostomum von Nordmann, 1832 in the light of the novel data. We strongly suggest the use of molecular evidence based on cox1 gene sequences (in addition to ITS1-5.8S-ITS2 sequences) in association with detailed assessment of the morphology of the larval stages in future studies of Diplostomum spp. in fish and snails.

Host traits explain the genetic structure of parasites: a meta-analysis.

Gene flow maintains the genetic integrity of species over large spatial scales, and dispersal maintains gene flow among separate populations. However, body size is a strong correlate of dispersal ability, with small-bodied organisms being poor dispersers. For parasites, small size may be compensated by using their hosts for indirect dispersal. In trematodes, some species use only aquatic hosts to complete their life cycle, whereas others use birds or mammals as final hosts, allowing dispersal among separate aquatic habitats. We performed the first test of the universality of the type of life cycle as a driver of parasite dispersal, using a meta-analysis of 16 studies of population genetic structure in 16 trematode species. After accounting for the geographic scale of a study, the number of populations sampled, and the genetic marker used, we found the type of life cycle to be the best predictor of genetic structure (Fst): trematode species bound to complete their life cycle within water showed significantly more pronounced genetic structuring than those leaving water through a bird or mammal host. This finding highlights the dependence of parasites on host traits for their dispersal, suggesting that genetic differentiation of parasites reflects the mobility of their hosts.

Upstream-downstream gradient in infection levels by fish parasites: a common river pattern?

Physical habitat structure can influence the distribution and abundance of organisms. In rivers, stream drift, a common process originating from the unidirectional water flow, favours the displacement and downstream dispersion of invertebrates. This process could also generate a gradient in infection levels, leading to decreasing numbers of parasites per host as one moves upstream from the river mouth. We tested this hypothesis using 4 trematode species infecting the fish Gobiomorphus breviceps in the Manuherikia River (New Zealand). We analysed the abundance of each trematode infrapopulation as a function of distance from the river junction and fish size by generalized linear models. Our results supported the existence of a longitudinal gradient in trematode abundance along the river with a decreasing downstream-to-upstream continuum. This applied to 3 out of the 4 trematode species studied, suggesting that this might be a common pattern in river populations. Thus, the unidirectional river flow and a major process like drift in lotic systems, that influences the dynamics and distribution of invertebrate hosts, can also affect trematodes. Host properties like habitat preference, and parasite traits, particularly those related to transmission mode can influence the strength of the observed gradient, as may other environmental and biotic factors.

Mining various genomic resources to resolve old alpha-taxonomy questions: A test of the species hypothesis of the Proteocephalus longicollis species complex (Cestoda: Platyhelminthes) from salmonid fishes.

High-throughput sequencing strategies became commonly employed to study non-model parasites, but the corresponding genomes and transcriptomes were seldom mined following the original publication. Similar to the data generated with genome skimming techniques based on shallow-depth shotgun genomes, various genomic and transcriptomic resources can be screened for useful molecular phylogenetic markers traditionally characterised with Sanger sequencing. Here, we provide an example of a strategy using reduced-representation genomic as well as transcriptomic data to obtain broad insights into the molecular diversity of the cestode Proteocephalus longicollis, a common parasite of salmonids distributed throughout the Holarctic region. We extract popular mitochondrial and nuclear ribosomal markers from various genomic resources for hundreds of parasite specimens from multiple European whitefish populations and compare those with Proteocephalus representatives from other species of salmonids and various geographical regions. In contrast with the previous morphology-based assessments, molecular phylogeny reveals a high degree of genetic divergence between Proteocephalus isolates from different salmonids, contrastingly low genetic differentiation within the parasite's populations hosted by the European whitefish (Coregonus lavaretus species complex), and a sister species relationship of Proteocephalus from European whitefish and Proteocephalus percae, a parasite of European perch (Perca fluviatilis). Proteocephalus spp. from North American lake whitefish, brown trout and Arctic charr each formed clearly distinct lineages. These results advance our understanding of the interrelationships of the Proteocephalus-aggregate, a well-recognized clade of Holarctic freshwater fish proteocephalids, and support resurrection of some of the nominal species of Proteocephalus, including Proteocephalus exiguus La Rue, 1911 from North American coregonids and Proteocephalus fallax La Rue, 1911 from European C. lavaretus, reserving Proteocephalus longicollis (Zeder, 1800) exclusively for parasites of Salmo trutta.

Sensitivity of bipartite network analyses to incomplete sampling and taxonomic uncertainty.

Bipartite network analysis is a powerful tool to study the processes structuring interactions in ecological communities. In applying the method, it is assumed that the sampled interactions provide an accurate representation of the actual community. However, acquiring a representative sample may be difficult as not all species are equally abundant or easily identifiable. Two potential sampling issues can compromise the conclusions of bipartite network analyses: failure to capture the full range of interactions (sampling completeness) and use of a taxonomic level higher than species to evaluate the network (taxonomic resolution). We asked how commonly used descriptors of bipartite antagonistic communities (modularity, nestedness, connectance, and specialization [H2 ']) are affected by reduced host sampling completeness, parasite taxonomic resolution, and their crossed effect, as they are likely to co-occur. We used a quantitative niche model to generate weighted bipartite networks that resembled natural host-parasite communities. The descriptors were more sensitive to uncertainty in parasite taxonomic resolution than to host sampling completeness. When only 10% of parasite taxonomic resolution was retained, modularity and specialization decreased by ~76% and ~12%, respectively, and nestedness and connectance increased by ~114% and ~345% respectively. The loss of taxonomic resolution led to a wide range of possible communities, which made it difficult to predict its effects on a given network. With regards to host sampling completeness, standardized nestedness, connectance, and specialization were robust, whereas modularity was sensitive (~30% decrease). The combination of both sampling issues had an additive effect on modularity. In communities with low effort for both sampling issues (50%-10% of sampling completeness and taxonomic resolution), estimators of modularity, and nestedness could not be distinguished from those of random assemblages. Thus, the categorical description of communities with low sampling effort (e.g., if a community is modular or not) should be done with caution. We recommend evaluating both sampling completeness and taxonomic certainty when conducting bipartite network analyses. Care should also be exercised when using nonrobust descriptors (the four descriptors for parasite taxonomic resolution; modularity for host sampling completeness) when sampling issues are likely to affect a dataset.

Life cycles, molecular phylogeny and historical biogeography of the 'pygmaeus' microphallids (Digenea: Microphallidae): widespread parasites of marine and coastal birds in the Holarctic.

The 'pygmaeus' microphallids (MPG) are a closely related group of 6 digenean (Platyhelminthes: Trematoda) Microphallus species that share a derived 2-host life cycle in which metacercariae develop inside daughter sporocysts in the intermediate host (intertidal and subtidal gastropods, mostly of the genus Littorina) and are infective to marine birds (ducks, gulls and waders). Here we investigate MPG transmission patterns in coastal ecosystems and their diversification with respect to historical events, host switching and host-parasite co-evolution. Species phylogenies and phylogeographical reconstructions are estimated on the basis of 28S, ITS1 and ITS2 rDNA data and we use a combination of analyses to test the robustness and stability of the results, and the likelihood of alternative biogeographical scenarios. Results demonstrate that speciation within the MPG was not associated with co-speciation with either the first intermediate or final hosts, but rather by host-switching events coincident with glacial cycles in the Northern Hemisphere during the late Pliocene/Pleistocene. These resulted in the expansion of Pacific biota into the Arctic-North Atlantic and periodic isolation of Atlantic and Pacific populations. Thus we hypothesize that contemporary species of MPG and their host associations resulted from fragmentation of populations in regional refugia during stadials, and their subsequent range expansion from refugial centres during interstadials.

Temporal stability of polymorphic Arctic charr parasite communities reflects sustained divergent trophic niches.

Polymorphic Arctic charr Salvelinus alpinus populations frequently display distinct differences in habitat use, diet, and parasite communities. Changes to the relative species densities and composition of the wider fish community have the potential to alter the habitat niche of sympatric Arctic charr populations. This study evaluated the temporal stability of the parasite community, diet, and stable isotopes (δ13C, δ15N) of three sympatric Arctic charr morphs (piscivore, benthivore, and planktivore) from Loch Rannoch, Scotland, in relation to changes to the fish community. All Arctic charr morphs displayed distinct differences in parasite communities, diet, and stable isotope signatures over time, despite the establishment of four new trophically transmitted parasite taxa, and increased fish and zooplankton consumption by the piscivorous and planktivore morphs, respectively. Native parasite prevalence also increased in all Arctic charr morphs. Overall, Loch Rannoch polymorphic Arctic charr morph populations have maintained their distinct trophic niches and parasite communities through time despite changes in the fish community. This result indicates that re-stocking a native fish species has the potential to induce shifts in the parasite community and diet of Arctic charr morphs.

Next-generation cophylogeny: unravelling eco-evolutionary processes.

A fundamental question in evolutionary biology is how microevolutionary processes translate into species diversification. Cophylogeny provides an appropriate framework to address this for symbiotic associations, but historically has been primarily limited to unveiling patterns. We argue that it is essential to integrate advances from ecology and evolutionary biology into cophylogeny, to gain greater mechanistic insights and transform cophylogeny into a platform to advance understanding of interspecific interactions and diversification more widely. We discuss key directions, such as incorporating trait reconstruction and considering multiple scales of network organization, and highlight recent developments for implementation. A new quantitative framework is proposed to allow integration of relevant information, such as quantitative traits and assessment of the contribution of individual mechanisms to cophylogenetic patterns.

Assembly rules of helminth parasite communities in grey mullets: combining components of diversity.

Organisms aggregate in ecological communities. It has been widely debated whether these associations are explained by deterministic or, in contrast, random processes. The answer may vary, depending on the level of an organisational scale (α, ß and γ) and the facet of diversity considered: taxonomic, functional and phylogenetic. Diversity at the level of a sampling unit (i.e. host individual) is the α diversity; ß diversity represents the extent of dissimilarity in diversity among sampling units (within a level of an organisational scale, ß1; between levels of an organisational scale, ß2); and the total diversity of a system is γ diversity. Thus, the combination of facets and levels of a scale may be useful to disentangle the mechanisms driving the composition of a parasite community. Using helminth parasite taxonomic, functional, and a proxy for phylogenetic diversity of three species of grey mullets (Teleostei: Mugilidae) from the Mediterranean Sea, we show that random and deterministic processes of different nature explain the assemblage of parasite communities. The parasite community at a host individual (α) was invariably a random subset of the total diversity in the community for the three facets of diversity. At the ß1 level, taxonomic diversity was lower than expected by chance, whereas functional diversity and the proxy for phylogenetic diversity were random. At the ß2 level, diversity patterns suggested environmental filtering of the parasite assemblage: species, trait, and phylogenetic compositions of parasite communities seemed to depend primarily on the species of host, but also on the locality and season. Our study shows that parasite communities are not totally understood if any of the components (i.e. facets and levels) of diversity is neglected.

A revision of the Haploporinae Nicoll, 1914 (Digenea: Haploporidae) from mullets (Mugilidae): Haploporus Looss, 1902 and Lecithobotrys Looss, 1902.

The status of the nominal species of Haploporus Looss, 1902 and Lecithobotrys Looss, 1902 is re-assessed by means of a comparative morphological study based on newly collected specimens from the western Mediterranean, the re-examination of museum material and a critical evaluation of published data. H. benedeni (Stossich, 1887) (type-species) is described and H. lateralis Looss, 1902 is considered to be its junior synonym. Additional data are given for H. pseudoindicus Rekharani & Madhavi, 1985, H. spinosus Machida, 1996 and H. magnisaccus Machida, 1996. Species parasitising Valamugil spp. from the Indo-West Pacific region, H. indicus Rekharani & Madhavi, 1985, H. spinosus, H. magnisaccus, H. mugilis Liu & Yang, 2002 and H. muscolosaccus Machida, 2003, are considered incertae sedis with respect to their generic affiliation. H. pacificus (Manter, 1963) (syn. Neohaploporus pacificus Manter, 1963), H. pseudoindicus and H. musculosaccus are designated as species inquirendae and H. lossii Al-Bassel, 1990 is considered to be a nomen nudum. Lecithobotrys putrescens Looss, 1902 is described based on newly collected material from Liza spp. Pseudolecithobotrys n. g. is erected to accommodate Lecithobotrys stomachicola Machida, 1996, as P. stomachicola (Machida, 1996) n. comb., from the North Pacific. L. aegyptiacus Hassan, El-Aziz, Khidr & Abu Samak, 1990 is considered to be a synonym of Saccocoelium tensum Looss, 1902, and L. brisbanensis (Martin, 1974) (syn. Paralecithobotrys brisbanensis Martin, 1974), L. vitellosus Sharma & Gupta, 1970 and L. suezcanali Nisreen Ezz El-Dien, Abdel-Rahman, El-Gawady, Imam & Fahmy, 1990 are regarded as species inquirendae. New generic diagnoses are presented for both Haploporus and Lecithobotrys.