Ectoparasite Species Research Articles

Identification of Arthropods by Polymerase Chain Reaction as Probes for Infectious Disease Studies in Experimental Coprolites

The study of arthropods is still scarce in paleoparasitology, especially their molecular identification. In this experimental study, we amplify DNA using a polymerase chain reaction from 2 ectoparasite species, Rhipicephalus sanguineus and Pediculus humanus capitis, in experimentally desiccated feces. This study shows perspectives for the study of the identification of arthropods in coprolites when taxonomic identification is not possible.

Bat Ectoparasites from Sint Eustatius, Lesser Antilles (Diptera: Hippoboscidae: Streblinae; Hemiptera: Polyctenidae)

In this paper 4 species of bat ectoparasites are recorded from the island of Sint Eustatius, Dutch Caribbean. One species of true bug (Hemiptera: Polyctenidae) as well as 3 species of bat flies (Diptera: Hippoboscidae: Streblinae) are recorded. All species are photographed. The first DNA barcodes for 3 bat ectoparasite species ( Trichobius frequens, Trichobius intermedius, and Hesperoctenes fumarius) have been posted to the BOLD database; DNA barcode sequences for a fourth species ( Megistopoda aranea) are the first from a Caribbean island.

Prevalence and Intensity of Ectoparasites of Tilapia (Oreochromis niloticus) in Ponds with Low, Medium and High Stocking Density

Research has been conducted on the difference in intensity value and prevalence of tilapia (Oreochromis niloticus) ectoparasites in ponds with low, moderate and high density in February to March 2018. This study aims to identify ectoparasite species and calculate the prevalence and intensity of ectoparasites maintained in solid low, medium and high stocking. Based on the results, the parasites were Trichodina nobilis, Dactylogyrus sp, Gyrodactylus sp and Oodinium sp. The highest prevalence values were found in low stocking densities of 100% including the very severe category and the highest intensity was 158.95 individuals/tail. The lowest prevalence values were found in medium and high stocking density of 78.3% and 70% included in the usual infection category and the highest intensity values had a value of 2.45 and 4.97 individuals/tail.

Seasonal variation in prevalence, parasite load and mean intensity of ectoparasites in Pipistrellus kuhlii (Chiroptera: Vespertilionidae) from Iran

We studied quantitatively the seasonal variation in prevalence, parasite load, and mean intensity of two species of ectoparasites in free ranging populations of Kuhl's bat, Pipistrellus kuhlii in western Iran. In total, 348 live bats (230 males and 118 females) were collected using mist net during May to November 2013. All bats identified as to sex and the number of ectoparasite species in each bat was counted. On 348 P. kuhlii captured, 5355 ectoparasites were observed. Two species of ectoparasites belonging to Argas vespertilionis (Argasidae) and Steatonyssus sp. (Macronyssidae) were identified. In late May and at the beginning of June, the peaks of ectoparasite load in bats were recorded and then dropped during June to November. The number of ectoparasites in pregnant female bats in May-June during pregnancy was significantly higher than non-pregnant females (p ≤ 0.05). A significant correlation was found between ectoparasite load and the ratio of body mass to the length of forearm (W/FA), as an index of body condition, indicating that parasite load has apparent impact on bat’s health. Our findings indicated that parasite loads correlate with season, sex and reproductive condition of the host.

Convergent evolution of mouthparts morphology between Siphonostomatoida and a new genus of deep-sea Aegisthidae Giesbrecht, 1893 (Copepoda: Harpacticoida)

A great diversity of the basal harpacticoid family Aegisthidae Giesbrecht, 1893 is found in the deep-sea benthic and hyperbenthic environments. Some members of this family have developed adaptations to dig into the sediment, while others have colonized hyperbenthic waters; however, no aegisthid associated with a vertebrate or an invertebrate host has yet been reported. During a sampling campaign aimed at evaluating the abyssal copepod fauna of the polymetallic province in the North East Pacific, we discovered a striking new genus of Aegisthidae which exhibits convergent evolution of mouthpart morphology with that of siphonostomatoid copepods. Siphonis gen. nov. has a labrum modified into a long oral cone similar to that found in ectoparasitic species of the primitive siphonostomatoid family, Asterocheridae Giesbrecht, 1899. The mandible, maxillule and maxilla of Siphonis gen. nov. are also modified into siphonostomatoid-like structures; however, some ground pattern characters of the family Aegisthidae are retained. The new genus is discussed and compared with members of the derived taxon Palinarthra, Seifried, 2003 which comprises all those harpacticoid families with an incipient oral cone and a slightly elongated mandibular gnathobase. Two species of the new genus are described herein and were verified by molecular evidence. Siphonis gen. nov. is placed within the subfamily Cerviniopseinae Brotskaya, 1963 and represents a third major shift in the lifestyle of aegisthid copepods, from benthic and hyperbenthic to associated forms (probably with sponges or cnidarians).

Efficacy of fluralaner spot-on solution for the treatment of Ctenocephalides felis and Otodectes cynotis mixed infestation in naturally infested cats

BackgroundCats can be infested with several ectoparasite species, especially Ctenocephalides felis and Otodectes cynotis. The aim of this study was to evaluate the efficacy of a single topical application of fluralaner against C. felis and O. cynotis natural infestation in stray (study 1) and owned (study 2) cats in central and southern Italy.ResultsThe number of live fleas found on each cat on Day 0 ranged from 1 to more than 30 (arithmetic mean live flea count = 11.9 in study 1; 14.6 in study 2) while no live fleas were found on days 7 and 84 post topical application of fluralaner. The number of live mites found on each cat on Day 0 ranged from 1 to 42 (arithmetic mean live mite count = 6.4 in study 1; 8.9 in study 2) while no live mites were found on days 7 and 84 post topical application of fluralaner.ConclusionsTopical fluralaner completely eliminated fleas and ear mites from infested cats and was 100% effective against both parasites up to 84 days after treatment.

Ectoparasites of the Nile Rat, Arvicanthis niloticus from Shendi area, Sudan

This study investigated the ectoparasites of the Nile Rat, Arvicanthis niloticus in Shendi area, River Nile State, Sudan. Eighty nine A. niloticus were collected for the first time from the horticultural fields of Shendi, between January to June 2018, and their entire fur was combed thoroughly, using a fine-tooth comb. Any removed ectoparasites were relaxed, mounted and examined under a microscope for morphological identification. Forty two (47.2%) of the collected rats was found infested, with an overall mean intensity of 13.4 (range 2–67) ectoparasites per an infested rat; 10 different species of ectoparasites were identified, including: 2 species of flea – Xenopsylla cheopis, Leptopsylla segnis; 3 species of louse – Polyplax spinulosa, P. abyssinica, P. serrata; a species of tick – Rhipicephalus sp.; 4 species of mite – Laelaps agilis, L. nuttalli, Ornitonyssus bacoti, Dermanyssuss gallinae. The most prevalent ectoparasite found was the flea Xenopsylla cheopis, 23.6%, followed by the mite Laelaps nuttalli, 10.1%, while the least was the mite Ornitonyssus bacoti, 1.1%. Significantly higher prevalence and intensity of infestation was found among male rats. Likewise, older rats significantly harbored a higher prevalence and intensity of infestation.

Annotated checklist of fleas (Insecta: Siphonaptera) and lice (Insecta: Anoplura) associated with rodents in Iran, with new reports of fleas and lice.

Rodent species reported from Iran are subject of several studies, but the fauna called ectoparasite, infesting the rodents, along with their epidemic effects, are poorly known. In this study, ectoparasitic insect fauna of rodents found across the Iran were studied, to generate an annotated checklist of fleas and lice species. Several field expeditions focused on different habitats of northeastern Iran were conducted between January 2017 and May 2018. Rodent trapping was carried out using custom-made mesh live traps and "Faragir" live traps baited mainly with scorched sunflower and gourd seeds. The trapped rodents were examined for ectoparasites on their body, and then released at their trapping point. The rodents and ectoparasite species were identified based on available keys. A total of 217 rodents belonging to 16 species of the families Calomyscidae, Cricetidae, Dipodidae, Mu- ridae and Sciuridae were captured. Five species of each fleas and lice were collected from the body of the trapped rodents. Three flea species, Ctenophthalmus pseudagyrtes, Nosopsyllus iranus and Xenopsylla buxtoni; and two louse species, Polyplax gerbilli and P. spinulosa, were recorded for the first time. The study generated an annotated checklist of 79 species of fleas and 8 species of lice harboured by different species of rodents distributed in Iran which would be helpful in different taxonomic studies such as parasite-host coevolution, and also sanitation and health monitoring programs.

Ectoparasites infesting dogs and cats in Bishoftu, central Oromia, Ethiopia

A total of 200 dogs and 137 cats were examined for the presence of fleas, ticks and lice in Bishoftu, central Oromia, Ethiopia from September 2009 through April 2010. At least one ectoparasite species was found on 97% (194/200) of the dogs and 90.5% (124/137) of the cats. On dogs, fleas (Ctenocephalides felis (95%), Pulex irritans (20.5%), Echidnophaga gallinacea (9%) and Xenopsylla cheopis (0.5%)), ticks (Haemaphysalis leachi (17.5%), Amblyomma variegatum (8.5%), Rhipicephalus sanguineus (8%), Rhipicephalus pulchellus (5.5%) and Rhipicephalus (Boophilus) decoloratus (2.5%)) and lice (Heterodoxus spiniger (5%), Linognathus setosus (1.5%) and Trichodectes canis (0.5%)) were identified. On cats, fleas (C. felis (61.7%), E. gallinacea (24.1%), P. irritans (1.5%) and X. cheopis (0.7%)) and ticks (Ha. leachi (10.9%), Am. variegatum (1.5%) and Rh. sanguineus (0.7%)) were identified. C. felis was identified as the predominant ectoparasite on both dogs and cats. The overall frequency and count of ectoparasites was higher on dogs than on cats. Significantly higher overall frequency of fleas on young versus adult cats (p = .01) was recorded. However, ticks were significantly higher on adult cats than on young cats (p = .01). In conclusion, this study demonstrated great species diversity and high frequency of ectoparasites on dogs and cats in the study area. Further studies are required to investigate the role of these ectoparasites in transmission of zoonotic pathogens to humans and animals in Ethiopia.

Ectoparasites of Birds from a Rice Field in Samarahan Division, Sarawa

Birds are easily infested with ectoparasites due to their fitness, foraging behaviour, nesting cavities, micro- and macro-habitats. However, the status of ectoparasite infestation on birds in Sarawak is widely unknown. Rice field provides food resources to a variety of birds. This study was conducted to determine the species composition of ectoparasites from birds in a rice field at Kuap Village, Samarahan, Sarawak. A total of 69 birds consists of five species were caught from the rice field and the most common bird species found was the Chestnut Munia (Lonchura atricapilla). From these, 55 were found infested with ectoparasites with the infestation prevalence of 79.71%. A total of 2,513 ectoparasites from eight species were recovered from this study which comprised of six species of mites, one species of soft tick, and one species from the class Insecta. The most dominant ectoparasite species was mite namely, Nanopterodectes sp. with a total of 1,626 individuals. This baseline data on the ectoparasite composition and infestation of birds is important as some of the ectoparasites have the potential in transmitting zoonotic diseases to the farmers working at the rice fields in this region. Keywords: Avian, Chestnut Munia, ectoparasite infestation, paddy plantation, Malaysia

Mites and Lice of Peri-Domestic Rodents Captured at a Mayan Community of Yucatán State, México

The main ectoparasites of small rodents at a Mayan community of Yucatan State, southeastern Mexico were determined. Rodents were trapped in peridomestic areas of 20 houses from March to September 2016. Ectoparasites were removed from the rodents and morphologically identified. Total rodents infested were 22.9% (53/231). Prevalence of ectoparasites by rodent species was 65% (13/20) on Sigmodon toltecus Saussure, 50% (4/8) on Peromyscus yucatanicus J.A. Allen & Chapman, 37.5% (3/8) on Heteromys gaumeri J.A. Allen & Chapman, 25% (30/120) on Rattus rattus L., and 4% (3/75) on Mus musculus L. In total, 250 ectoparasites were collected. Mites were identified as Androlaelaps fahrenholzi (Berlese) (n = 115), Echinolaelaps echidninus (Berlese) (n = 89), and Steptolaelaps heteromys Furman (n = 22), and lice were identified as Polyplax spinulosa (Burmeister) (n = 24). Results suggested association among particular ectoparasite and rodent species, i.e., P. spinulosa and E. echidninus with R. rattus. Likewise, S. heteromys was significantly associated with H. gaumeri, and A. fahrenholzi with S. toltecus. The presence of ectoparasites such as E. echidninus and P. spinulosa on peridomestic rodents indicated risk of pathogen transmission to humans in the study area; therefore, focusing on surveillance and control of rodents in household environments is imperative.

Prevalence of ectoparasite infestations in owned dogs in Kwara State, Nigeria

In Nigeria, dogs are the common companions in many households and, harbor wide range of ectoparasites of severe zoonotic potentials. A cross sectional survey was conducted to examine the prevalence, intensity and risk factors of ectoparasite infestation among the owned dogs in Kwara state, Nigeria. A total of 333 dogs were screened for ectoparasites, and questionnaires were applied to obtain information regarding; age, sex, breeds, coat colour and management practices by dog owners. Two hundred and seventy one (81.4%) dogs were infested with at least one species of ectoparasite and multiple infestations recorded mostly among the female dogs. Six species of ectoparasites of three taxa were identified: ticks (Rhipicephalus sanguineus sensu lato, Haemaphysalis leachii and Amblyomma variegatum), fleas (Ctenocephalides canis and C. felis) and louse (Heterodoxus spiniger). R. sanguineus s.l. was the most prevalent (70.3%) followed by C. felis (42.1%) and H. spiniger (30.0%). Intensities of C. felis, H. spiniger and R. sanguineus s.l infestations were significantly higher in female and younger dogs (p < 0.001). Ectoparasites occurrence varied with breed and coat colour of host. A high prevalence of ectoparasite infestation recorded is at variance with the knowledge of dogs' owners in this study area. Therefore, intervention based on provision of veterinary clinics and prevention and management of parasite infestation in endemic area would mitigate the possible health hazard associated with the ectoparasitic infestation of dogs.

Virulence of Aerial Conidia of Beauveria bassiana Produced under LED Light to Ctenocephalides felis (Cat Flea).

Ctenocephalides felis is an ectoparasitic flea species commonly found on dogs and cats. The current study verified the in vitro virulence of conidia of the entomopathogenic fungus Beauveria bassiana produced under different color LED light (red, blue, purple, green, yellow, and white) to adults of C. felis. The fungal isolates were cultivated on malt extract agar (MEA). Bioassay treatments used aerial conidia in test tubes. Adult fleas were obtained from a house cat in Chiang Mai province, Thailand. The experiments were composed of one control and eleven treatment groups. All of the treatments with B. bassiana conidia caused adult mortality after an exposure of 12 h. Among the conditions used in this study, B. bassiana cultured under red LED and fluorescent light were the most effective in causing mortality (100 %) in adult fleas after 36 h. The experimental results indicate that these aerial conidia of B. bassiana have promising potential for use in control of C. felis adult stages.

EFFECT OF FOREST COVER ON ECTOPARASITES OF SMALL MAMMALS IN THE BRAZILIAN ATLANTIC FOREST

Habitat reduction is one of the greatest threats to biodiversity and one of its many expected consequences is the negative impacts on host species. In this study, we evaluated if the reduction in the forest cover positively affected the richness and abundance of ectoparasites and rates of parasitism on mammal species. The study was carried out in the Atlantic Forest biome in the state of Bahia between January to March and September to November of 2011. We sampled four areas with different amounts of forest cover (%) in the municipalities of Valenca (25%), Nilo Pecanha (35%), Camamu (45%) and Jaguaripe (55%). We identified twenty species of ectoparasites (fleas, mites, ticks) on 130 small mammals from 18 species (14 rodents and four marsupials), and the most abundant ectoparasites were mites. We confirmed our main hypothesis: the greater richness and abundance of ectoparasites was associated with a reduction in forest cover, with possible epidemiological implications. The prevalence of ectoparasitism per area varied from 91% in Valenca to 50% in Jaguaripe. The mean intensity of ectoparasites per host was 6.5 for Valenca, 6.4 for Nilo Pecanha, 10.4 for Camamu and 3.2 for Jaguaripe. Ours findings confirm that the reduction in the amount of forested is related to amplified rates of parasitism and changes in ectoparasites abundance and species richness.

Morphological and molecular (28S rRNA) data of monogeneans (Platyhelminthes) infecting the gill lamellae of marine fishes in the Campeche Bank, southwest Gulf of Mexico.

During the examination of 913 fish specimens belonging to four families in the Campeche Bank (Gulf of Mexico), 23 gill ectoparasitic monogenean species were found, which belong to three families: Dactylogyridae, Microcotylidae and Diclidophoridae. The species Euryhaliotremaamydrum, E.carbuncularium, E.dunlapae, E.fajeravilae, E.fastigatum, E.longibaculum, E.paracanthi, E.tubocirrus, Haliotrematoidescornigerum, H.gracilihamus, H.heteracantha, H.longihamus, H.magnigastrohamus, H.striatohamus, Hamatopedunculariabagre, Neotetraonchusbravohollisae, and N.felis (all Dactylogyridae) were found on the hosts Lutjanussynagris, L.griseus, Ariopsisfelis, Bagremarinus, Archosargusrhomboidalis, and Haemulonplumieri. Additionally, Microcotylearchosargi, Microcotyle sp., and Microcotyloidesincisa (all Microcotylidae) were found on L.griseus and A.rhomboidalis; finally, Choricotyle sp. 1, Choricotyle sp. 2, and Choricotyle sp. 3 (all Diclidophoridae) were found on H.plumieri. The prevalence, abundance, mean intensity of infection, and supplementary taxonomic revisions for all monogeneans found are provided. Partial sequences of the 28S rRNA gene were also obtained for monogeneans of ariid, sparid, and haemulid host fishes to explore their systematic position within the Monogenea. New locality and host records for some previously described species of Euryhaliotrema, Hamatopeduncularia, Microcotyle, and Choricotyle from lutjanid, ariid, sparid, and haemulid hosts were reported. The present study adds evidence supporting the interoceanic occurrence of the same monogenean species (on lutjanids) on the west-east Atlantic and Pacific Oceans (= amphiamerican species). As previously suggested, there are at least, two possibilities to explain that parasite distribution: differentiation of morphological features in these monogeneans have resulted in only slight to insignificant morphological changes developing over the extended period of 3.2 mya (when the Isthmus of Panama was closing) and/or speciation is only evident at molecular level.

Association of ectoparasites (Diptera and Acari) on bats (Mammalia) in a restinga habitat in northeastern Brazil.

In Brazil, 124 species of ectoparasites of bats are known from the families Streblidae, Nycteribiidae, and Spinturnicidae. This study aimed to characterize the ectoparasites associated with bats in a restinga habitat in Sergipe, northeastern Brazil. Sampling occurred between October 2016 and September 2017 in the Reserva Particular do Patrimônio Natural do Caju through the capture of bats, using 10 mist nets. The ectoparasites collected were stored in 70% alcohol and subsequently identified. For the hosts, the parasitological indexes were calculated and, for the most abundant ones, the influences of the sex of the host and of seasonality on these indexes were evaluated. We collected 430 parasites, of which 77.90% belonged to the Streblidae family. The influence of host sex was observed only in terms of the prevalence between Periglischrus iheringi and Artibeus lituratus, with the highest values observed for females. This may be associated with the highest susceptibility of females to parasitism by the greater permanency in the shelter. In terms of the influence of seasonality, only the interaction between Carollia perspicillata and Trichobius joblingi was affected by temperature, with an increase in prevalence rates and mean intensity during the season with lower temperatures. This relationship may be associated with biological differences among parasites species. The present study identified six new species of ectoparasites and the occurrence of ticks on bats for Sergipe, in addition to registering 11 new bat-ectoparasite associations for the state and two for Brazil, contributing to an increase in our knowledge about bat-ectoparasite interactions.

The Spatial Distribution of Perch (Perca fluviatilis) Ectoparasites and the Effect of Chemical Water Quality Parameters on Ectoparasite Spatial Niche Size

Abstract Seasonal changes of abiotic factors and their influence on parasite occurrence have repeatedly been studied. Most of the studies have been conducted to evaluate the effect of water physicochemical parameters on changes in the intensity of infection, prevalence and component community of a number of parasite species. However, insufficient attention has been paid to the link between water quality parameters and spatial niche size of ectoparasites. The distribution of ectoparasite species on perch (Perca fluviatilis L.) was studied to establish whether seasonal changes of water quality parameters are associated with ectoparasite spatial niche size. The concentration of phosphates (PO4 3−), nitrates (NO− 3), sulphates (SO4 2−) and dissolved oxygen (DO) in the water of Lake Sila (Latvia) was measured every month throughout the year and recorded all ectoparasites on perch. Zero-inflated mixed models were used to evaluate which of the water parameters influence the spatial niche size of ectoparasites. Our findings showed that spatial niche size of some ectoparasite species is affected by a set of water quality parameters and that this effect is negative. The spatial niche size of Anodonta cygnea was negatively associated with phosphate, nitrate, sulphate and dissolved oxygen concentration. The spatial niche size of Ancyrocephalus percae was negatively associated with sulphate, and the spatial niche size of Ergasilus sieboldi was negatively associated with nitrate concentration.

Arthropods and associated pathogens from native and introduced rodents in Northeastern Italy.

Introduced Siberian chipmunks Eutamias sibiricus have been reported to be important reservoirs for human Lyme disease, as they may host high numbers of hard ticks carrying Borrelia spp. and other pathogens. In the present study, we assessed the prevalence of Borrelia spp. and other pathogenic bacteria in ectoparasite arthropod species infesting Siberian chipmunks and coexisting native small rodents. Small rodents were trapped with Sherman traps in Veneto (NE Italy), where the largest Italian populations of chipmunks occur. A total of 14 individual ticks were found on 223 rodents, with 6 more ticks obtained from stored dead chipmunks from the same study area. Ectoparasites were screened for pathogens by molecular analyses including species-specific PCR amplifications. Rickettsia monacensis, Borrelia lusitaniae, and Anaplasma platys were present in the parasites of both native rodents and introduced chipmunks. The present findings suggest a role for the invasive species E. sibiricus in the maintenance of the Ixodes ricinus life cycle, which may result in the modification of the transmission dynamics of tick-borne pathogens. Moreover, the presence of Rickettsia in urban populations of chipmunks may represent a serious risk for human health and should be investigated further.

Inventarisasi dan Komposisi Jenis Ektoparasit Ikan Nila (Oreochromis niloticus) Sebagai Biomonitoring Perairan Sungai Tukad Badung, Bali

Environmental stressors which coming from anthropogenic wastes that indirectly enters into the river waters also affect the biota's health in the ecosystem such as the Tilapia Fish (Oreochromis niloticus) which is found in the waters of the Tukad Badung River, Bali. The presence of parasites in fish is also associated with changes of the water quality. The objectives of this study is to provide data and information on the inventory and composition of the parasite species in Tilapia fish (Oreochromis niloticus) as the aquatic health biomonitoring of in the effort of sustainable river ecosystem management. The results of ectoparasit observation of the Tilapia which obtained from five stations in Tukad Badung waters found 6 types of ectoparasites, which are Trichodina sp. Dactylogyrus sp. Gyrodactylus sp., Chilodonella sp., Vorticella sp. and Lernea sp. The composition of the ectoparasite species of nila tilapia fish (Oreochromis niloticus) obtained from all five research stations in Tukad Badung waters by percentage of presence of ectoparasite Trichodina sp. are 70%, Dactylogyrus sp. 31%, Gyrodactylus sp. 4% and Chilodonella sp., Vorticella sp. and Lernea sp. 1%.

&lt;b&gt;Parasites in Loricariidae from Brazil: checklist and new records for fish from the Brazilian Amazon

The aim of this study was to investigate the parasites fauna of Ancistrus leucostictus, Hypostomus ventromaculatus, Ancistrus sp. and Hemiancistrus sp. from the Igarapé Fortaleza River (Amapá State, Brazil), besides making a checklist of the parasite species in Loricariidae from Brazil. A total of 53 fishes were collected from November 2013 to August 2014. In the hosts, a total of 1,559 parasites of seven taxa were collected: Unilatus unilatus, Trinigyrus mourei, undetermined metacercariae, Genarchella gernachella, Raphidascaris (Sprentascaris) sp., Gorythocephalus elongorchis and Proteocephalus sp. Ectoparasite species were frequent in the examined Loricariidae species, which also had larval stages of endoparasites. The hosts with the highest sampled number, H. ventromaculatus and Ancistrus sp., had the highest parasite species richness. Loricariidae species from Brazil are parasitized by species of Protozoa, Monogenea, Nematoda, Digenea, Acantocephala, Cestoda, Crustacea and Hirudinea, but monogeneans, digeneans and nematodes were the predominant taxa.