Day 3: Morphological Taxonomy v1

Day 3: ADE practical instructions for morphological identifications

Gastronautidae Deroux, 1994 and Trithigmostoma Jankowski, 1967: Evolutionary Links Among Cyrtophorian Ciliates (Protista, Ciliophora, and Phyllopharyngea)

Studies on cyrtophorian ciliates (Cyrtophoria) have accumulated much knowledge on morphological taxonomy and molecular phylogeny, and the general classification and phylogenetic relationships of most families have thereby been revealed. However, the phylogenetic position of the family Gastronautidae Deroux, 1994 remains uncertain. This is due to the presence of specialized characteristics (in particular a circumoral kinety in a closed circle), and most importantly, the lack of molecular data of this family. In addition, TrithigmostomaJankowski, 1967 holds a special position among genera in Chilodonellidae Deroux, 1976 due to its divergent characteristics. In the present work, we studied a new gastronautid, Gastronauta paraloisi sp. n., and three populations of Trithigmostoma cucullulus (Müller, 1786) Jankowski, 1967, using integrative methods. Species identifications were confirmed by morphological research. We also obtained SSU rDNA sequences, which included the first available sequence of Gastronautidae. The following SSU rDNA-inferred phylogenetic analyses showed that the establishment of the family Gastronautidae is necessary, and Gastronautidae and Trithigmostoma may represent intermediate evolutionary links in the order Chlamydodontida.

The order Tethyida (Porifera) in California: taxonomy, systematics, and the first member of the family Hemiasterellidae in the Eastern Pacific

Sponges (phylum Porifera) are ubiquitous inhabitants of marine ecosystems and have been shown to provide substantial ecosystem services. Despite this ecological importance, the sponge fauna in California has received little study. Here I use a collection of kelp forest sponges to describe the diversity of the order Tethyida in California. This order contains the genus Tethya, which has been included in long-term ecological monitoring projects. I show that Tethya vacua is a junior synonym of Tethya californiana, and thus all Tethya populations known in California belong to a single species. Genetic data from California's only Timeidae, Timea authia, indicate that this species is in fact in the Tethyidae and is the third known member of the genus Tethytimea. I also describe the first member of the family Hemiasterellidae from the Eastern Pacific, Galaxia gaviotensis gen. nov. sp. nov. By combining field photographs, morphological taxonomy, and phylogenetic analysis of these samples, this work will facilitate future efforts to understand the evolution of this order and the ecological role of sponges in the California kelp forest.

Comparative analysis of morphological and molecular approaches integrated into the study of the dinoflagellate biodiversity within the recently deposited Black Sea sediments – benefits and drawbacks

One of the assets, assigned to the phytoplankton resting stages, is that of serving as the “memory” of the aquatic ecosystems and preserved biodiversity in the course of time. However, an accurate cyst identification proves to be a more difficult and extremely challenging process, even today. In order to gain a better taxonomic coverage of cyst assemblages in the Black Sea, an integrated approach of the classical morphological identification with metabarcoding methods (MySeq sequencing of V7-V9 regions of the 18S rDNA) was applied on thirteen surface sediment samples collected from different sites. A total number of 112 dinoflagellate taxa was detected at the species level and ascribed to 51 genera. In general, it is the molecular analysis that yields a higher number of taxa as compared to those obtained through the morphological taxonomy (66 taxa based on the DNA sequences versus 56 morphologically-identified taxa). Besides, it should be pointed out that the integrated dataset includes 14 potentially toxic dinoflagellate species. Discerned, subsequently, was a good dataset consistency for ten species, followed by some discrepancies as to a number of taxa, identified with one of the methods only, due to specific methodological biases. On the whole, it could be concluded that the combination of morphological and molecular methods is likely to increase the potential for a more reliable taxonomic assessment of phytoplankton diversity in marine sediments which, in turn, proves conclusively the utmost importance of the integrated approach.

Phylogenomics of Piranhas and Pacus (Serrasalmidae) Uncovers How Dietary Convergence and Parallelism Obfuscate Traditional Morphological Taxonomy

The Amazon and neighboring South American river basins harbor the world’s most diverse assemblages of freshwater fishes. One of the most prominent South American fish families is the Serrasalmidae (pacus and piranhas), found in nearly every continental basin. Serrasalmids are keystone ecological taxa, being some of the top riverine predators as well as the primary seed dispersers in the flooded forest. Despite their widespread occurrence and notable ecologies, serrasalmid evolutionary history and systematics are controversial. For example, the sister taxon to serrasalmids is contentious, the relationships of major clades within the family are inconsistent across different methodologies, and half of the extant serrasalmid genera are suggested to be non-monophyletic. We analyzed exon capture to reexamine the evolutionary relationships among 63 (of 99) species across all 16 serrasalmid genera and their nearest outgroups, including multiple individuals per species to account for cryptic lineages. To reconstruct the timeline of serrasalmid diversification, we time-calibrated this phylogeny using two different fossil-calibration schemes to account for uncertainty in taxonomy with respect to fossil teeth. Finally, we analyzed diet evolution across the family and comment on associated changes in dentition, highlighting the ecomorphological diversity within serrasalmids. We document widespread non-monophyly of genera within Myleinae, as well as between Serrasalmus and Pristobrycon, and propose that reliance on traits like teeth to distinguish among genera is confounded by ecological homoplasy, especially among herbivorous and omnivorous taxa. We clarify the relationships among all serrasalmid genera, propose new subfamily affiliations, and support hemiodontids as the sister taxon to Serrasalmidae. [Characiformes; exon capture; ichthyochory; molecular time-calibration; piscivory.]

New Molecular Data on Filaria and its Wolbachia from Red Howler Monkeys (Alouatta macconnelli) in French Guiana—A Preliminary Study

Previous studies have reported filarial parasites of the genus Dipetalonema and Mansonella from French Guiana monkeys, based on morphological taxonomy. In this study, we screened blood samples from nine howler monkeys (Alouatta macconnelli) for the presence of filaria and Wolbachia DNA. The infection rates were 88.9% for filaria and 55.6% for wolbachiae. The molecular characterization, based on the 18S gene of filariids, revealed that A. macconnelli are infected with at least three species (Mansonella sp., Brugia sp. and an unidentified Onchocercidae species.). Since the 18S and cox1 generic primers are not very effective at resolving co-infections, we developed ITS genus-specific PCRs for Mansonella and Brugia genus. The results revealed coinfections in 75% of positives. The presence of Mansonella sp. and Brugia sp. was also confirmed by the 16S phylogenetic analysis of their associated Wolbachia. Mansonella sp., which close to the species from the subgenus Tetrapetalonema encountered in New World Monkeys, while Brugia sp. was identical to the strain circulating in French Guiana dogs. We propose a novel ITS1Brugia genus-specific qPCR. We applied it to screen for Brugia infection in howler monkeys and 66.7% were found to be positive. Our finding highlights the need for further studies to clarify the species diversity of neotropics monkeys by combining molecular and morphological features. The novel Brugia genus-specific qPCR assays could be an effective tool for the surveillance and characterization of this potential zoonosis.

Diversity of Galaxauraceae (Nemaliales, Rhodophyta) in northeastern Brazil: new record and two new species, Dichotomaria viridis sp. nov. and Tricleocarpa laxa sp. nov.

Many studies have focused on the taxonomy and phylogeny of the family Galaxauraceae with the use of molecular markers, allied to morphological taxonomy, providing a better understanding of the phylogenetic relationships within the family, as well assisting with the specific delimitation. For the Brazilian coast, Galaxauraceae has few studies with morphological taxonomy, but lack studies with a molecular focus. The diversity of Galaxauraceae was assessed in northeastern Brazil (Bahia state) using rbcL and COI-5P, as well as morpho-anatomical analyses. We report four species from Brazil: Dichotomaria huismanii (the first report for the Brazilian coast), D. obtusata, Galaxaura rugosa, and Tricleocarpa fragilis. Molecular and morphological data supported the establishment of two new species for Galaxauraceae: Tricleocarpa laxa sp. nov. and Dichotomaria viridis sp. nov. Tricleocarpa laxa formed a well-supported clade sister to T. natalensis (South Africa, type locality) and T. cylindrica (Australia) in both rbcL and COI-5P analyses, whereas Dichotomaria viridis, formed a moderate clade sister to D. huismanii. The Brazilian sequences of D. huismanii grouped with sequences from the type locality (Bermuda) showing no intraspecific divergence for rbcL, and very low divergence values for COI-5P. The record of D. huismanii in Brazil expands its geographical distribution to the South Atlantic Ocean. Male plants are described for the first time for this species. Even though our results are restricted to a region of northeastern Brazil (Bahia), they clearly revealed a hidden diversity of Galaxauraceae in Brazil.