Peritrich Ciliate Research Articles

Love story or fling? The first observation of Vorticella sp. (Ciliophora: Peritrichia) on the freshwater snail Gyraulus rossmaessleri (Auerswald, 1852)

Love story or fling? The first observation of Vorticella sp. (Ciliophora: Peritrichia) on the freshwater snail Gyraulus rossmaessleri (Auerswald, 1852)

Histopathology and Phylogeny of the Dinoflagellate Hematodinium perezi and the Epibiotic Peritrich Ciliate Epistylis sp. Infecting the Blue Crab Callinectes sapidus in the Eastern Mediterranean.

Bioinvasions constitute both a direct and an indirect threat to ecosystems. Direct threats include pressures on local trophic chains, while indirect threats might take the form of an invasion of a microorganism alongside its host. The marine dinoflagellate Hematodinium perezi, parasitizing blue crabs (Callinectes sapidus), has a worldwide distribution alongside its host. In Greece, fluctuations in the blue crab population are attributed to overexploitation and the effects of climate change. The hypothesis of the present study was that blue crab population reductions cannot only be due to these factors, and that particular pathogens may also be responsible for the fluctuations. To investigate this hypothesis, both lethargic and healthy blue crab specimens were collected from three different fishing sites in order to assess the health status of this important species. Together with the lethargic responses, the hemolymph of the infested crabs presented a milky hue, indicating the first signs of parasitic infestation with H. perezi. The histopathological results and molecular identification demonstrated the effect of the presence of H. perezi in the internal organs and their important role in the mortality of blue crabs. Specifically, H. perezi, in three different tissues examined (heart, gills, hepatopancreas), affected the hemocytes of the species, resulting in alterations in tissue structure. Apart from this dinoflagellate parasite, the epibiotic peritrich ciliate Epistylis sp. was also identified, infecting the gills. This study represents the first detection of H. perezi in the eastern Mediterranean, demonstrating that this is the main causative agent of blue crab mortality on Greek coastlines.

New record of Epistylis obliqua Sommer, 1951 (Ciliophora, Peritrichia) on aquatic mite Unionicola minor (Soar 1900) (Acari, Hydrachnidia)

This article deals with the report of a colonial peritrich ciliate species Epistylis obliqua Sommer, 1951 as epibiont on hydrachnid mite Unionicola minor (Soar 1900) from the freshwater in Amsterdam, the Netherlands. The finding of the species is the first after its original description as well as the first finding on a mite which belongs to family Unionicolidae Oudemans, 1909. The systematic position, improved diagnosis and morphometrics characteristic of E. obliqua are presented in the present study.

On four epibiotic peritrichous ciliates (Protozoa, Ciliophora) found in Lake Weishan Wetland: morphological and molecular data support the establishment of a new genus, Parapiosoma gen. nov., and two new species

During a study on the diversity of ciliated protists in Lake Weishan Wetland, the largest wetland in northern China, four epibiotic sessilid peritrichs were isolated from aquatic host animals. Two of them, i.e., Epistylis cambari Kellicott, 1885 and Epistylis lwoffi Fauré-Fremiet, 1943, were known species whereas the other two, i.e., Parapiosoma typicum gen. nov., sp. nov. and Orborhabdostyla gracilis sp. nov., are new to science. The new genus Parapiosoma gen. nov. is characterized by its branched non-contractile stalk, everted peristomial lip, obconical macronucleus and transverse silverlines. Two species are assigned to the new genus, namely Parapiosoma typicum sp. nov. and Parapiosoma gasterostei (Fauré-Fremiet, 1905) comb. nov. Morphologically, P. typicum sp. nov. is recognized by its goblet-shaped zooids, single-layered peristomial lip, dichotomously branched stalk, and infundibular polykinety 3 (P3) containing three equal-length rows. Orborhabdostyla gracilis sp. nov. is characterized by its slender zooid, curved macronucleus, and three equal-length rows in infundibular P3. Improved diagnoses and redescriptions of E. cambari and E. lwoffi are provided including, for the first time, data on the ciliature of E. cambari. Phylogenetic analyses based on SSU rDNA, ITS1-5.8S rDNA -ITS2, and LSU rDNA sequence data strongly support the assertion that the family Epistylididae comprises morphospecies with different evolutionary lineages and indicate that Parapiosoma gen. nov. may represent a new taxon at family level.

Taxonomy and phylogeny of Pseudovorticella ciliates (Ciliophora, Peritrichia): Two new and one rare species from the coastal waters of China

Peritrich ciliates are a species-rich group of sessile unicellular eukaryotes, which can be found in various aquatic habitats from all over the world. It is well accepted that there are still many ciliates to be uncovered. During a survey on ciliate biodiversity in the coastal waters of China, three solitary peritrich species were identified as members of the genus Pseudovorticella Foissner & Schiffmann, 1975, including two new species and a rare one. Pseudovorticella zhejiangensis sp. n. differs from its congeners mainly by having a conical-shaped zooid, conspicuous pellicular blisters, one ventral and one dorsal contractile vacuoles, and an infundibular polykinety 3 with three rows of nearly equal length but different beginning positions. Pseudovorticella dalianensis sp. n. can be defined mainly by an obovoid-shaped zooid, one ventral contractile vacuole, and a three-rowed infundibular polykinety 3 with the middle row being the longest. The rare species, Pseudovorticella verrucosa (Dons, 1915) Sun et al., 2009, was redescribed. The small subunit (SSU) rDNA sequences of these three species were sequenced for the first time, the phylogeny of Pseudovorticella species was analyzed, and the results verified the non-monophyly of this genus. This study demonstrates that the morphologic and gene barcoding data are the optimum combination to disclose the biodiversity of ciliates.

Structure and Dynamics of Periphyton in a Neotropical Freshwater Lake, with Emphasis on Ciliates and Their Relationships with Bacterial Taxa.

Periphyton communities in freshwater systems play an essential role in biogeochemical processes, but knowledge of their structure and dynamics lags far behind other environments. We used eDNA metabarcoding of 16S and 18S rRNA markers to investigate the formation and establishment of a periphytic community, in addition to a morphology-based approach for peritrich ciliate determinations, its most abundant group. We sampled two nearby sites within a large Neotropical lake at four time points, aiming to assess whether periphyton establishment can be replicated on this local scale. Producers and denitrifiers were abundant in the community, illustrating the relevant role of biofilms in freshwater nutrient recycling. Among microeukaryotes, peritrich ciliates dominated the community, with genera Epistylis and Vorticella being the most abundant and showing a clear succession at both sites. Other ciliates were morphologically identified and, in some cases, their occurrence was strongly related to bacterial abundance. The structure of both prokaryotic and eukaryotic components of periphyton was not different, while the turnover dynamics differed between the two sites, in spite of their adjacent locations and similar abiotic properties. This indicates that the establishment of these communities can vary even on a local scale within a lake ecosystem.

New record of Chromistan parasites of copepods and rotifers in Iraqi marine and brackish waters

The present study was focused on the infections of some zooplankton groups (copepoda and rotifer) with ecto and endo parasites in Iraqi marine and estuarine brackish water during the period from January to the end of October 2010 by seasonally intervals. Samples were collected from 5 selected stations represent Iraqi marine and brackish waters. Many parasites were recorded on copepods and other zooplankton in the study area, these are: Ellobiopsis chattoni, Ellobiopsis sp., Thalassomyces sp., Blastodinium sp., Zoothamnium sp., Dinoflagellate and peritrich ciliates. These parasites were recorded for the first time in Iraqi marine and brackish waters except for Ellobiopsis chattoni, and the genus Thalassomyces sp. which were recorded in Kuwaiti waters before. The percentage and the intensity of infections were studied; the highest percentage of infections copepods was 35.7% in winter at station 4, while the lowest was 0.73% at stations 2 during autumn. The highest percentage of infections in rotifers was 9.49% at station 1 during autumn, while the lowest percentage was 0.15 % at station 3 during winter. The highest mean intensity of the copepods was 12.03 at station 1 during summer, while the lowest value was 1.05 in the same station during autumn. The highest mean intensity of the copepods and rotifers was 6.3 at station 2 during summer, while the lowest was 0.8 in the same station during autumn. Scanning Electron Microscope (SEM) was used in this study for identification of some ecto parasites of copepods.

"Hitchhicking with invertebrates": two reports of epibiosis by peritrich ciliates on ostracods and hydrachnid mites in tanks of epiphytic bromeliads from south Brazil.

Temporary waters are common environments found in physical and biological substrates. Among them, some bromeliads species are known to hold water in their tanks, in a habitat called phytotelmata. Phytotelmata serve as habitats for several organisms, from bacteria and protists to arthropods and anurans. Peritrich ciliates are often found as epibionts on aquatic invertebrates in these environments. Here, we report two cases of epibiosis involving Lagenophrys sp. attached to ostracods (Elpidium spp.) and Rhabdostyla sp. colonizing hydrachnid mites in the tanks of two bromeliad species. In our analysis, we measured the frequency of epibiosis considering the presence of both basibiont and epibiont in the samples. The results shown a significant difference between Elpidium sp. and Lagenophrys sp. compared to hydrachnid mites and Rhabdostyla sp. (87.5% and 19%, respectively), supported by the Kruskal-Walis test (p = 0.0003, Chi-square = 9.687). These reports are important since the knowledge of phytotelmata communities from tropical and subtropical areas is incipient, although it has been increasing over the last years. It also shows that epibiosis doesn't always represent a beneficial relationship. These two epibiosis systems found in bromeliad tanks raise questions about organism's dispersal throughout other phytotelmata and other temporary water habitats.

New records for associations between peritrich protozoan ciliates (Ciliophora, Sessilida) and polychaete worms (Annelida) from off the southeastern coast of India.

We report herein three epibiotic associations between peritrich ciliate protozoans and polychaete worms, as observed in Tamilnadu, southeastern coast of India. Epibiont ciliates Epistylis sp.1 were found all over the integument of individuals of the terebellid polychaete Terebella sp., collected from Vellar estuary. Epistylis sp.2 ciliates were observed attached to Namalycastis abiuma polychaetes, on both sides of parapodia. Cothurnia sp. ciliates were found on anterior most paleae and hooks of Sabellaria sp. polychaetes, both latter associations from material from the Uppanar estuary. Those epibiont/basibiont associations are all new to science and discussed herein, together with a review on the previous reports of epibiont ciliate protozoans in Indian waters.

New observations on the large hemidiscoid diatom Palmerina ostenfeldii and its symbiotic ciliate Vaginicola collariforma sp. nov. from subtropical Australian waters

The large hemi-discoid diatom Palmerina ostenfeldii was common in subtropical Moreton Bay, Australia, following a flood in January 2011. All diatom cells exhibited diagnostic subapical folds settled by loricate peritrich ciliates, but which readily abandoned stressed diatom cells. We characterized both diatoms and ciliates by morphological and molecular analyses, including careful video observations on non-preserved cells immediately after collection. The fold in the diatom cell wall comprises a narrow shelf upon which the ciliates attach (on average seven per fold, and similar for the two folds of a single diatom cell) but without penetrating the diatom wall itself. Folds were fully developed in newly formed internal valves, indicating that the ciliates play no role in their morphogenesis. SSU rRNA sequences of P. ostenfeldii from Moreton Bay (with ciliates) differed by 25 bp (1.5%) from those of P. hardmaniana from Texas (without ciliates), but surprisingly rbcL chloroplast sequences for both diatom species were indistinguishable. The ciliate species epiphytic on P. ostenfeldii, previously referred to as the cold-water tintinnid Amphorella borealis could not be assigned to any known species. We formally describe it here as Vaginicola collariforma sp. nov. within the crown clade of peritrichs which also includes the closely related genus Cothurnia (but distinguished as having an external stalk). Beating of the peritrich oral cilia was observed to drive rotational movement of the large discoid diatoms as in a ferris wheel. The observed diatom-ciliate symbiosis may represent a unique evolutionary adaptation in which the ciliate is host-specific and attaches in a specific locality on the host cell.

Ecological studies on some planktonic organisms at Mahallet Ziad Wastewater treatment plant in El Gharbia Province, Egypt

This study was carried out at Mahallet Ziad wastewater treatment plant in El-Gharbia Province during a period extending between Feb. 2018 and Jan. 2019. Major planktonic groups and certain physico-chemical parameters were investigated monthly at this water plant to elucidate its performance efficiency in treating and enhancing the wastewater. It was apparently that protozoa and rotifers represent the major groups in that wastewater treatment plant. Protozoa are represented by three major phyla (Sarcodina, Mastigophorea and Ciliophora) where the ciliated protozoans prevail the other two phyla. The numerical densities of sessile peritrich ciliates were less abundant than other ciliated protozoan types (crawling and swimming ciliates). It was proved that the maximal and minimal numerical densities of total protozoans of the present investigation exhibited 6956 and 1716x 102/L during March and December, respectively. Simultaneously, the uppermost numerical values of sarcodines, flagellates and ciliates were 565, 2211 and 56312/L during May, February and April, while the lowest ones were 30, 87 and 1716x 102/L on September, July and December, respectively. Different types of protozoan were proved to be significantly influenced to varying levels with certain physico-chemical parameters. From the technological point of view, it was proved that the performing efficiency of the activated sludge of the present study is more or lessparallel to those of other wastewater treatment plants in different provinces of Egypt which gives an indication that there is a critical strategic need for the government to have more treated water to be used in agricultural and industrial activities.

A checklist of ciliate epibionts (Ciliophora) found on bryozoans.

A compilation of the ciliate (Ciliophora) species found on marine and fresh water bryozoans as epibionts has been carried out based on published records. The checklist includes the taxonomic position of each species of epibiontic ciliate, the species of basibiont bryozoans, localities and the bibliographic references. Altogether 40 ciliate species from classes Spirotrichea (two species); Suctorea (sixteen species); Oligohymenophorea, subclass Peritrichia (sixteen species) and Heterotrichea, family Folliculinidae (six species) were listed. Among registered species, six were reported on bryozoans only. Only one species of peritrich ciliate Ellobiophrya conviva adapted to inhabit on tentacles of bryozoans with special adhesive organelle (cinctum or adhesive ring) indicate a possible specific to bryozoan host.

Picoplankton feeding by the ciliate Vorticella similis in comparison to other peritrichs emphasizes their significance in the water purification process

We measured the feeding and growth rates of the sessile peritrich ciliate Vorticella similis on seven picocyanobacterial strains and their accompanying bacterial flora in microcosm experiments. This ciliate and several closely related Vorticella species are important indicators in the activated sludge of water treatment plants and contribute significantly to the water purification process. The picocyanobacteria were isolated from oligo-mesotrophic subalpine lakes in Austria, central Europe, and represent different pigment types (phycoerythrin-rich, PE, and phycocyanin-rich, PC) and phylogenetic clusters. In contrast to most previous studies with peritrich ciliates, we calculated growth and grazing rates of V. similis from relatively long-term incubations (48 h). Ingestion and clearance rates were calculated from the rate of disappearance (ROD) of prey in experimental containers with ciliates, relative to controls without ciliates. The results confirmed the hypothesis that V. similis is an indiscriminative suspension feeder that would not select for prey features other than cell size. Ciliate ingestion rates depended on picoplankton abundance and biomass, but the type of the functional response of peritrich ciliates awaits further study. In particular, it needs to be tested if their grazing activity declines strongly at moderate to low food levels. The ROD method combined with the precise assessment of picoplankton abundances by flow cytometry that we used yielded moderately higher estimates of the ciliate feeding activity as previous short-term experiments using fluorescently labeled prey. The picocyanobacterial and bacterial ingestion rates that we obtained are the highest values thus far reported for sessile peritrich ciliates. Clearance rates of V. similis were also high but comparable to those of two other peritrich ciliate species. Our results can be used to quantify the tremendous significance of peritrich ciliates in the water purification process.

Larvicidal Effect of Vorticella microstoma (Ehrenberg, 1830) on Mosquito Larvae, and Morphological Changes under Induced Environmental Conditions.

Development of microbiota assemblage usually occurs in all most all domestic and peridomestic mosquito breeding habitats. There may be parasitic, epibiont, pathogenic, or even predatory species among this biota, and to investigate their potential against the mosquito population is worth studying. This may contribute to formulating environmentally agreeable approaches in controlling mosquitoes which is a current need. Vorticella spp. is a peritrich ciliate, and its trophont stage has become epibiont to certain biota. Further, their existence in seasonal water bodies that dry off during drought in tropical weather conditions is not known. Therefore, the potential of the larvicidal effect of Vorticella microstoma on different species of mosquito larvae was studied. We found that V. microstoma causes the 100% death of the third instar larvae of Culex tritaeniorhynchus (Giles, 1901) within 48 h of exposure. In contrast to that, this species did not cause any mortality to Aedes albopictus (Skuse, 1894) and Aedes aegypti (Linnaeus in Hasselquist, 1762) mosquito larvae in repeated trials. The dynamics of polymorphism of V. microstoma was studied under induced environmental conditions. V. microstoma remained as trophont stage throughout at room temperature (25 ± 2°C). When the temperature was reduced to 6°C, V. microstoma settled in the cyst stage. Evidently, V. microstoma is a good biocontrol agent of Culex species mosquito larvae, and they able to overcome drought periods in cyst forms. The findings of this study would be considered as the first step for a new avenue to work on environmentally agreeable manner in reducing the Culex spp. mosquito populations.

Symbioses of Ciliates (Ciliophora) and Diatoms (Bacillariophyceae): Taxonomy and Host–Symbiont Interactions

The nature of the plankton symbioses between ciliates and diatoms has been investigated from the tropical South Atlantic Ocean, and Mediterranean and Caribbean Seas. The obligate symbioses of the diatoms Chaetoceros dadayi or C. tetrastichon with the tintinnid Eutintinnus spp., and Chaetoceros coarctatus with the peritrich ciliate Vorticella oceanica are the most widespread, and the consortium of Chaetoceros densus and Vorticella sp. have been rediscovered. Facultative symbioses between Eutintinnus lususundae and Chaetoceros peruvianus, Hemiaulus spp., and Thalassionema sp. are less frequent, often containing three or four partners because Hemiaulus can also harbor the diazotrophic cyanobacteria Richelia intracellularis. Another three-partner consortium is the peritrich ciliate Zoothamnium pelagicum, ectobiont bacteria, and the diatom Licmophora sp. The predominantly oligotrophic conditions of tropical seas do not favor the survival of large diatoms, but large species of Coscinodiscus and Palmerina in facultative symbiosis with Pseudovorticella coscinodisci have a competitive advantage over other diatoms (i.e., reduction of sinking speed and diffusive boundary layer). Symbioses allow sessile peritric ciliates to extend their distribution in the pelagic environment, permit boreal-polar related diatoms such as C. coarctatus or Fragilariopsis doliolus to inhabit tropical seas, and help large diatoms to extend their survival under unfavorable conditions.

A checklist of ciliates (Ciliophora) inhabiting on ostracods (Crustacea, Ostracoda).

A compilation of the ciliated species found on freshwater and marine ostracods as epibiont or parasite (endobiont) has been carried out based on published records. The checklist includes the taxonomic position of each species of epibiontic and endobiontic ciliate, the species of basibiont ostracodes, the geographic zones and the bibliographic references where they were recorded. Altogether 7 suctorian, 29 peritrich, one apostome and one scuticociliatid species were listed. Two of recorded suctorian species are possible specific to marine ostracodes, whereas only one, Tokophrya sibirica to freshwater hosts. Fourteen species of peritrichs are likely specific to freshwater ostracodes, while three possible specific to marine ostracode hosts. Other suctorian and peritrich ciliate species were found on a variety of host taxa. One species of scuticociliatid was recorded as endobiont in ostracod.

Symbiotic interactions between ciliates (Ciliophora) and diatoms (Bacillariophyceae)

Introduction: Diatoms and ciliates are important components of the marine plankton community, and some species are able to develop symbiotic associations in the tropical seas. Objective: To describe the nature of the symbioses, the morphological adaptations of the members, and the possible ecological advantages of the symbiotic life versus the free-living forms. Methods: Plankton samples were collected from Mediterranean and Caribbean Seas, and the South Atlantic Ocean. Consortia were examined during laboratory incubations, including studies of the motility and the feeding currents by high-speed video recordings, and culture tests of the species as symbiotic or free-living forms. Results: The consortia of the diatoms Chaetoceros dadayi and C. tetrastichon with the tintinnid Eutintinnus spp., and C. coarctatus with the peritrich ciliate Vorticella oceanica are examples of an obligate mutualism. The cultures of the host diatoms as free-living organism were unsuccessful. The consortia between Eutintinnus lususundae and the diatoms Chaetoceros peruvianus, Hemiaulus hauckii, H. membranaceus, and Thalassionema sp. are facultative symbioses. These are examples of three or four partner consortia because Hemiaulus spp. is the host of the diazotrophic cyanobacteria Richelia intracellularis. Other example of facultative three partner consortium is the peritrich ciliate Zoothamnium pelagicum with an ectobiont bacteria, and the diatom Licmophora sp. The barrel-shaped chains of the diatom Fragilariopsis dolious encircled the lorica of Salpingella spp., while these chains were almost flat in the free-living stage. The peritrich ciliate Pseudovorticella coscinodisci lives on large pelagic diatoms such as Coscinodiscus and Palmerina. These symbioses are facultative for the diatoms, but they extended their survival under unfavorable conditions. High-speed video recordings of the consortium of Vorticella oceanica and Chaetoceros coarctatus revealed that during the stalk contraction the zooid of reached 5 400 body length s-1, being the fastest organism with respect to its size. The consortia of Chaetoceros densus and an undescribed species of Vorticella is re-discovered. Conclusions: These symbioses have allowed that the sessile peritric ciliates colonize the pelagic environment and the proliferation of diatoms with a polar origin in the tropical sea.

Newly discovered associations between peritrich ciliates (Ciliophora: Peritrichia) and scale polychaetes (Annelida: Polynoidae and Sigalionidae) with a review of polychaete–peritrich epibiosis

AbstractIn this research, we report the presence of two ciliate protozoans of the subclass Peritrichia, Cothurnia amphicteis and C. peloscolicis, as epibionts on the chaetae of scaled polychaetes Malmgrenia lilianae, M. andreapolis (fam. Polynoidae) and Sthenelais boa (fam. Sigalionidae), from the north Adriatic (Mediterranean Sea). Both ciliate species are herein found for the first time after their original description and are redescribed, based on light and scanning electron microscopy analyses. This is the first record of an association between ciliates and polychaetes of the family Sigalionidae. Our results suggest that these host–epibiont relationships might be highly specific. We also present the first review of epibiosis between polychaetes and peritrich ciliates, indicating that this relationship is more diverse than previously thought. Forty taxa of peritrich ciliates from 12 genera and seven families are recorded as epibionts on polychaetes, while 48 polychaete taxa are known as their hosts. The relationship can be considered ectocommensalism, where the ciliates have the advantages of increased food availability. This association might be a more widespread phenomenon than currently known, because it could be easily overlooked or misinterpreted. It, therefore, deserves careful attention and further investigation.

Taxonomy and phylogeny of Pseudovorticella littoralis sp. n. and P. alani sp. n. (Ciliophora: Peritrichia) from coastal waters of southern China

The morphology, infraciliature, and silverline system of two peritrich ciliates, Pseudovorticella littoralis sp. n. and P. alani sp. n., isolated from coastal waters of southern China, were investigated based on both living and silver-stained specimens. Pseudovorticella littoralis sp. n. is characterized by the following combination of characters: cell inverted cone-shaped; contractile vacuole ventral; J-shaped macronucleus; infundibular polykinety 3 with two kinetosome rows of equal length; 19–26 silverlines from peristome to trochal band and 5–14 from trochal band to scopula. Pseudovorticella alani sp. n. is characterized by: cell inverted bell-shaped; contractile vacuole ventral; J-shaped macronucleus recurved almost forming a loop; infundibular polykinety 3 with three kinetosome rows, outer two rows longer than inner one; 48–61 silverlines between peristome and aboral trochal band, and 12–20 between aboral trochal band and scopula. The SSU rDNA sequences of both new species are reported and their genetic distances with congeners and phylogenetic relationships are investigated. Pseudovorticella and Epicarchesium cluster into two subclades with low support values. One subclade contains nearly all the available sequences of Pseudovorticella and Epicarchesium. Another one contains P. monilata and E. pectinatum. This calls on the need of a generic re-classification of Pseudovorticella and Epicarchesium based on more morphological and molecular data.

New Myxophagan water beetles from Madagascar (Coleoptera: Torridincolidae, Hydroscaphidae).

Myxophagan water beetles from Madagascar are comprehensively revised. Holotypes of the two previously known species are re-described and illustrated. Six new species of Incoltorrida Steffan and one new species of Hydroscapha LeConte are described and illustrated. The larvae of Incoltorrida quintacostata are illustrated and discussed. The presence of peritrich ciliates of the genus Platycola Kent on specimens of Incoltorrida madagassica Steffan is discussed and illustrated. Habitus, habitats, and male genitalia are illustrated, and distributions are mapped. The following new species are described (type localities parenthetic): Incoltorrida benesculpta n. sp. (Fianarantsoa, 3.2km S Ambohimanjaka); I. galoko n. sp. (Antsiranana, Diana, Ambilobe, Antsaba, Galoko mountains ); I. magna n. sp. (Antsiranana, Diana, Ambilobe, Antsaba, Galoko mountains); I. marojejy n. sp. (Antsiranana, Sava, Marojejy National Park); I. quintacostata n. sp. (Fianarantsoa, 3.5km N Ivato); I. zahamena n. sp. (Toamasina, Alaotra-Mangoro, Zahamena National Park); Hydroscapha andringitra n. sp. (Fianarantsoa, Ambilavao, Sendrisoa, approx. 10km N of Andringitra National Park).