Endoparasitic Lifestyle Research Articles

New deep-sea species of Aborjinia (Nematoda, Leptosomatidae) from the North-Western Pacific: an integrative taxonomy and phylogeny.

Marimermithid nematodes parasitising invertebrates are mainly found in the deep-sea environments. Several adult and juvenile specimens marimermithids of the genus Aborjinia have been found in bottom sediments and inside Polychaeta during recent cruises to the Kuril-Kamchatka trench and the Kuril Basin (the Sea of Okhotsk). New species are described based on integrative study. Aborjiniaprofundasp. nov. differs from A.eulagiscae by the location of the ventral gland cell bodies (posterior to the nerve ring vs posterior to the cardia), by the smaller body size (23-28 mm vs 103-132 mm) and shorter tail (193-263 µm vs 500-850 µm). BI and ML phylogenetic analyses based on 18S and 28S rDNA suggest that genus Aborjinia belongs to the family Leptosomatidae. Based on molecular and morphological characters the new genus Paraborjiniagen. nov. is proposed for A.corallicola. Within the family Leptosomatidae the new genus differs from all genera except Aborjinia by its endoparasitic lifestyle and hologonic ovaries. Paraborjiniagen. nov. differs from Aborjinia by the position of cephalic sensitive organs (outer labial and cephalic papillae in two separate circles vs outer labial and cephalic papillae in one circle) and by the parasitic adult (vs free-living in Aborjinia).

Hardly Venus’s servant—morphological adaptations of Veneriserva to an endoparasitic lifestyle and its phylogenetic position within Dorvilleidae (Annelida)

Endoparasitic annelids living inside another annelid host are known, particularly with regard to Oenonidae, but in general are poorly studied. The dorvilleid Veneriserva pygoclava is known from southern California, and its genus name (Latin = Venus’s servant) alludes to the close association with the host aphroditid scaleworm Aphrodita longipalpa. Little is known on fundamental questions on the biology of Veneriserva pygoclava. What is its mode of reproduction? How do they feed? How do they penetrate the host? We have studied multiple parasitized hosts and V. pygoclava specimens, using an integrative approach, combining µCT, histology, and electron microscopy. 3D reconstructions from µCT data of a parasitized Aphrodita show the exact position of the parasites in their natural condition within the host’s coelomic cavity. Ultrastructural investigations of the parasites revealed interesting adaptations to their lifestyle such as the complete reduction of their gut, despite the presence of a functional jaw apparatus and a modified epidermis enabling nutrient uptake from the host’s coelomic fluid. In addition to these, we also investigated spermatogenesis and oogenesis in V. pygoclava. Sperm morphology indicates an external fertilization of eggs within the coelomic cavity of the host. Mature male and female parasites living inside the same mature host and the presence of juvenile V. pygoclava within juveniles of Aphrodita suggest an obligate form of parasitism with a very early penetration of the hosts. In addition to our detailed morphological investigation, we conducted a phylogenetic analysis showing the position of Veneriserva within Dorvilleidae and its position was recovered nested among taxa of the Iphitime. Our phylogenetic analyses also show that the taxation Ophryotrocha puerilis siberti should be given full species rank and referred to as Ophryotrocha siberti. Finally, we publish here the full mitochondrial genome of V. pygoclava and discuss its novel gene order with reference to other annelids.

The evolution of endoparasitism and complex life cycles in parasitic platyhelminths

Within flatworms, the vast majority of parasitism is innate to Neodermata, the most derived and diversified group of the phylum Platyhelminthes.1,2 The four major lineages of Neodermata maintain various combinations of life strategies.3 They include both externally (ecto-) and internally feeding (endo-) parasites. Some lineages complete their life cycles directly by infecting a single host, whereas others succeed only through serial infections of multiple hosts of various vertebrate and invertebrate groups. Food sources and modes of digestion add further combinatorial layers to the often incompletely understood mosaic of neodermatan life histories. Their evolutionary trajectories have remained molecularly unresolved because of conflicting evolutionary inferences and a lack of genomic data.4 Here, we generated transcriptomes for nine early branching neodermatan representatives and performed detailed phylogenomic analyses to address these critical gaps. Polyopisthocotylea, mostly hematophagous ectoparasites, form a group with the mostly hematophagous but endoparasitic trematodes (Trematoda), rather than sharing a common ancestor with Monopisthocotylea, ectoparasitic epithelial feeders. Phylogenetic placement of the highly specialized endoparasitic Cestoda alters depending on the model. Regardless of this uncertainty, this study brings an unconventional perspective on the evolution of platyhelminth parasitism, rejecting a common origin for the endoparasitic lifestyle intrinsic to cestodes and trematodes. Instead, our data indicate that complex life cycles and invasion of vertebrates' gut lumen, the hallmark features of these parasites, evolved independently within Neodermata. We propose the demise of the traditionally recognized class Monogenea and the promotion of its two subclasses to the class level as Monopisthocotyla new class and Polyopisthocotyla new class.

The Sapria himalayana genome provides new insights into the lifestyle of endoparasitic plants

BackgroundSapria himalayana (Rafflesiaceae) is an endoparasitic plant characterized by a greatly reduced vegetative body and giant flowers; however, the mechanisms underlying its special lifestyle and greatly altered plant form remain unknown. To illustrate the evolution and adaptation of S. himalayasna, we report its de novo assembled genome and key insights into the molecular basis of its floral development, flowering time, fatty acid biosynthesis, and defense responses.ResultsThe genome of S. himalayana is ~ 1.92 Gb with 13,670 protein-coding genes, indicating remarkable gene loss (~ 54%), especially genes involved in photosynthesis, plant body, nutrients, and defense response. Genes specifying floral organ identity and controlling organ size were identified in S. himalayana and Rafflesia cantleyi, and showed analogous spatiotemporal expression patterns in both plant species. Although the plastid genome had been lost, plastids likely biosynthesize essential fatty acids and amino acids (aromatic amino acids and lysine). A set of credible and functional horizontal gene transfer (HGT) events (involving genes and mRNAs) were identified in the nuclear and mitochondrial genomes of S. himalayana, most of which were under purifying selection. Convergent HGTs in Cuscuta, Orobanchaceae, and S. himalayana were mainly expressed at the parasite–host interface. Together, these results suggest that HGTs act as a bridge between the parasite and host, assisting the parasite in acquiring nutrients from the host.ConclusionsOur results provide new insights into the flower development process and endoparasitic lifestyle of Rafflesiaceae plants. The amount of gene loss in S. himalayana is consistent with the degree of reduction in its body plan. HGT events are common among endoparasites and play an important role in their lifestyle adaptation.

Correction to: Genomic Adaptations to an Endoparasitic Lifestyle in the Morphologically Atypical Crustacean Sacculina carcini (Cirripedia: Rhizocephala)

Correction to: Genomic Adaptations to an Endoparasitic Lifestyle in the Morphologically Atypical Crustacean <i>Sacculina carcini</i> (Cirripedia: Rhizocephala)

The interna of the rhizocephalan Peltogaster reticulata: Comparative morphology and ultrastructure

Specialized morphology of diverse parasitic crustaceans reflects their adaptations to an endoparasitic lifestyle. Rhizocephalan barnacles are one of the most highly modified obligatory parasites of other crustaceans. Comprehension of the functional morphology of rhizocephalans could elucidate the main evolutionary trends not only inside parasitic barnacles, but in parasitism as a whole. Despite that, the available morphological information on the rhizocephalans is very fragmented. In this study, we examined the organization and ultrastructural features in different parts of the interna of Peltogaster reticulata (fam. Peltogastridae). The main trunk cuticle is much thicker than that of the side branches due to the different functions of these body parts. The central lumen in the main trunk is lined by an extracellular matrix, while the side branches are not. Muscular fibers are only present in the body wall of the main trunk, where they are organized as a “wicker basket”. Furthermore, functional differentiation can be found at the ultrastructural level in the cells of the rootlets: there are distinct cell types both in hypodermal and axial cell layers. The rootlets of P. reticulata are covered by a network of the host's neurons and capillaries.

Evolutionary Transitions of Parasites between Freshwater and Marine Environments.

Evolutionary transitions of organisms between environments have long fascinated biologists, but attention has been focused almost exclusively on free-living organisms and challenges to achieve such transitions. This bias requires addressing because parasites are a major component of biodiversity. We address this imbalance by focusing on transitions of parasitic animals between marine and freshwater environments. We highlight parasite traits and processes that may influence transition likelihood (e.g., transmission mode, life cycle, host use), and consider mechanisms and directions of transitions. Evidence for transitions in deep time and at present are described, and transitions in our changing world are considered. We propose that environmental transitions may be facilitated for endoparasites because hosts reduce exposure to physiologically challenging environments and argue that adoption of an endoparasitic lifestyle entails an equivalent transitioning process as organisms switch from living in one environment (e.g., freshwater, seawater, or air) to living symbiotically within hosts. Environmental transitions of parasites have repeatedly resulted in novel forms and diversification, contributing to the tree of life. Recognizing the potential processes underlying present-day and future environmental transitions is crucial in view of our changing world and the current biodiversity crisis.

Mitogenome-wise codon usage pattern from comparative analysis of the first mitogenome of Blepharipa sp. (Muga uzifly) with other Oestroid flies

Uziflies (Family: Tachinidae) are dipteran endoparasites of sericigenous insects which cause major economic loss in the silk industry globally. Here, we are presenting the first full mitogenome of Blepharipa sp. (Acc: KY644698, 15,080 bp, A + T = 78.41%), a dipteran parasitoid of Muga silkworm (Antheraea assamensis) found in the Indian states of Assam and Meghalaya. This study has confirmed that Blepharipa sp. mitogenome gene content and arrangement is similar to other Tachinidae and Sarcophagidae flies of Oestroidea superfamily, typical of ancestral Diptera. Although, Calliphoridae and Oestridae flies have undergone tRNA translocation and insertion, forming unique intergenic spacers (IGS) and overlapping regions (OL) and a few of them (IGS, OL) have been conserved across Oestroidea flies. The Tachinidae mitogenomes exhibit more AT content and AT biased codons in their protein-coding genes (PCGs) than the Oestroidea counterpart. About 92.07% of all (3722) codons in PCGs of this new species have A/T in their 3rd codon position. The high proportion of AT and repeats in the control region (CR) affects sequence coverage, resulting in a short CR (Blepharipa sp.: 168 bp) and a smaller tachinid mitogenome. Our research unveils those genes with a high AT content had a reduced effective number of codons, leading to high codon usage bias. The neutrality test shows that natural selection has a stronger influence on codon usage bias than directed mutational pressure. This study also reveals that longer PCGs (e.g., nad5, cox1) have a higher codon usage bias than shorter PCGs (e.g., atp8, nad4l). The divergence rates increase nonlinearly as AT content at the 3rd codon position increases and higher rate of synonymous divergence than nonsynonymous divergence causes strong purifying selection. The phylogenetic analysis explains that Blepharipa sp. is well suited in the family of insectivorous tachinid maggots. It's possible that biased codon usage in the Tachinidae family reduces the effective number of codons, and purifying selection retains the core functions in their mitogenome, which could help with efficient metabolism in their endo-parasitic life style and survival strategy.

Plant Biology: Genome Reveals Secrets of the Alien Within

The genome of the parasitic plant Sapria himalayana reveals extraordinary changes that reflect its endoparasitic lifestyle. The genome has lost many genes, including the entire chloroplast genome, but has gained genes through horizontal gene transfer and repeated transposable elements.

Meristem Genes in the Highly Reduced Endoparasitic Pilostyles boyacensis (Apodanthaceae)

The family Apodanthaceae comprises two genera (Apodanthes and Pilostyles) and 14 endoparasitic species, all of them lacking root and shoot apical meristems, stems and leaves. Their vegetative phase is reduced to a mycelium-like endophyte formed by strands of parenchyma cells that are in close contact to the host vasculature. These plants become apparent only when their tiny gregarious flowers emerge breaking through the host cortex. The lack of vegetative meristems in these plants sharply contrasts to the typical formation of floral meristems. Our target species, Pilostyles boyacensis, provides a suitable system to investigate the evolution of meristem –related genes in an endoparasitic flowering plant without a typical vegetative shoot apical meristem. We have generated transcriptomes from two different developmental stages of the parasite (emerged floral buds and fruits), as well as a mixed sample that comprises the endophyte and growing floral buds of the parasite and its host, Dalea cuatrecasasii (Fabaceae). We specifically assessed copy number and domain conservation for the WUSCHEL HOMEOBOX, LRR-RLK-IX-a, and CLE families related to the maintenance of the shoot apical meristem (SAM) as well as the ARF and LFY families responsible for floral meristem identity. Five out of the 11 canonical gene families responsible for SAM maintenance and floral fate determinacy targeted in this study were found in Pilostyles. P. boyacensis shows at least one transcript with all functional domains conserved for BAM1, WUS, WOX9, ARF7 and LFY. Other genes implicated in the canonical regulatory network could not be found, including ARF5, ARF19, BAM2, BAM3, CLV1, and CLV3. In conclusion, the endoparasitic lifestyle of Apodanthaceae appears to correlate with a substantial reduction in the transcriptomic machinery linked to SAMs, whereas the genes involved in flower fate have remained intact.

Interactions of endoparasitic and ectoparasitic nematodes within the plant root system.

Root-knot and cyst nematodes have sophisticated mechanisms to invade their plant hosts to reprogram the plant developmental program to induce feeding structures essential for nematode survival and reproduction. This has a detrimental effect on the plant as this sedentary endoparasitic interaction affects the growth and yields of many crop plants. However, other migratory endoparasitic nematodes that do not establish root feeding sites are as aggressive on many crop plants. With new information gained from the genome and transcriptomes of the migratory endoparasitic nematode, Pratylenchus spp., this review compares the different lifestyles and the pathogenic interactions these nematodes have with their plant host. Pratylenchus spp. utilises a common arsenal of effectors involved in plant cell wall degradation and the manipulation of plant host innate immunity. The absence of specific cell reprogramming effector genes may explain its migratory endoparasitic lifestyle, making it relevant to pest management approaches in Australia.

Supplementary description of Novophytoptus stipae Keifer 1962 (Acariformes, Eriophyoidea) with LT-SEM observation on mites from putatively conspecific populations: cryptic speciation or polyphagy of novophytoptines on phylogenetically remote hosts?

Supplementary descriptions of an infrequently encountered species Novophytoptus stipae Keifer 1962 (Eriophyoidea, Phytoptidae) from Achnatherum speciosum (Poaceae) based on topotypes recovered from dry plant material from California is given. Comparison of topotypes of N. stipae with fresh Novophytoptus mites from Juncus tenuis and J. balticus (Juncaceae) collected in West Virginia and Ohio failed to reveal distinct morphological differences sufficient enough to establish new taxa. All studied mites are considered belonging to one species, N. stipae. This is putatively an example of polyphagous eriophyoid species inhabiting phylogenetically remote hosts. Remarks on polyphagy and dispersal modes in eriophyoids are addressed. Uncommon features of the gnathosoma and the anal region of novophytoptines were discovered under LT-SEM. These findings emphasize peculiarities of novophytoptines in relation to their endoparasitic life style and underline numerous gaps in our knowledge on anatomy and functioning of the organism of eriophyoid mites.

Spermatological characteristics of the enigmatic monogenean Dictyocotyle coeliaca Nybelin, 1941 (Monopisthocotylea: Monocotylidae) reveal possible adaptation to endoparasitism.

Spermatological characters of Dictyocotyle coeliaca Nybelin, a unique endoparasitic monogenean from the body cavity of the ray Amblyraja radiata (Elasmobranchii: Rajidae), was investigated by means of scanning and transmission electron microscopy for the first time. The process of the spermatozoon formation begins with the appearance of the differentiation zone which contains two centrioles. Subsequently developed two free flagella rotate to lie parallel before their fusing. After fusion, both the mitochondrion and nucleus migrate alongside the axonemes. Spermatids are formed within parallel cytoplasmic canals. During late spermiogenesis, an electron-dense spiral end-piece is formed proximally to the centriolar region of some spermatids. At the end of spermiogenesis, this end-piece is separated by a plasma membrane from the late spermatid and remains in the residual cytoplasm when spermatozoa are released into the testis lumen. The mature spermatozoon of D. coeliaca contains two parallel axonemes with the 9 + "1" trepaxonematan pattern, mitochondrion, nucleus, parallel cortical microtubules, and electron-dense granules. Especially the presence of electron-dense granules, occurring frequenly in the spermatozoa of endoparasitic flatworms, may indicate an adaptation to endoparasitic lifestyle in D. coeliaca. The anterior extremity of the male gamete contains one centriolar derivative, a small component of the second centriolar derivative and anterior extremity of the mitochondrion. The posterior extremity of the mature spematozoon exhibits tubular elements of the disorganized axoneme. Variations of the spermatozoon ultrastructural characters within monocotylid monogeneans and possible evolutionary significance of glycogen in sperm to the endoparasitic habit are discussed.

Insights into Adaptations to a Near-Obligate Nematode Endoparasitic Lifestyle from the Finished Genome of Drechmeria coniospora.

Nematophagous fungi employ three distinct predatory strategies: nematode trapping, parasitism of females and eggs, and endoparasitism. While endoparasites play key roles in controlling nematode populations in nature, their application for integrated pest management is hindered by the limited understanding of their biology. We present a comparative analysis of a high quality finished genome assembly of Drechmeria coniospora, a model endoparasitic nematophagous fungus, integrated with a transcriptomic study. Adaptation of D. coniospora to its almost completely obligate endoparasitic lifestyle led to the simplification of many orthologous gene families involved in the saprophytic trophic mode, while maintaining orthologs of most known fungal pathogen-host interaction proteins, stress response circuits and putative effectors of the small secreted protein type. The need to adhere to and penetrate the host cuticle led to a selective radiation of surface proteins and hydrolytic enzymes. Although the endoparasite has a simplified secondary metabolome, it produces a novel peptaibiotic family that shows antibacterial, antifungal and nematicidal activities. Our analyses emphasize the basic malleability of the D. coniospora genome: loss of genes advantageous for the saprophytic lifestyle; modulation of elements that its cohort species utilize for entomopathogenesis; and expansion of protein families necessary for the nematode endoparasitic lifestyle.

Insights into the venom composition and evolution of an endoparasitoid wasp by combining proteomic and transcriptomic analyses.

Parasitoid wasps are abundant and diverse hymenopteran insects that lay their eggs into the internal body (endoparasitoid) or on the external surface (ectoparasitoid) of their hosts. To make a more conducive environment for the wasps’ young, both ecto- and endoparasitoids inject venoms into the host to modulate host immunity, metabolism and development. Endoparasitoids have evolved from ectoparasitoids independently in different hymenopteran lineages. Pteromalus puparum, a pupal endoparasitoid of various butterflies, represents a relatively recent evolution of endoparasitism within pteromalids. Using a combination of transcriptomic and proteomic approaches, we have identified 70 putative venom proteins in P. puparum. Most of them show higher similarity to venom proteins from the related ectoparasitoid Nasonia vitripennis than from other more distantly related endoparasitoids. In addition, 13 venom proteins are similar to venoms of distantly related endoparasitoids but have no detectable venom matches in Nasonia. These venom proteins may have a role in adaptation to endoparasitism. Overall, these results lay the groundwork for more detailed studies of venom function and adaptation to the endoparasitic lifestyle.

Elucidating the Life History and Ecological Aspects of Allodero hylae (Annelida: Clitellata: Naididae), A Parasitic Oligochaete of Invasive Cuban Tree Frogs in Florida.

Given their ubiquitous nature, it is surprising that more oligochaete annelid worms (Annelida: Clitellata) have not adopted an endoparasitic lifestyle. Exceptions, however, are the understudied members of the genus Dero (Allodero) that parasitize the ureters of tree frogs and toads. This study experimentally explores the life cycle and host specificity of Allodero hylae, the worm's use of chemical cues in host searching, and its seasonal prevalence and abundance over a year-long collection period on the Florida Southern College campus. A total of 2,005 A. hylae was collected from the ureter, urinary bladder, or expressed urine of wild Osteopilus septentrionalis ; a significant positive correlation was found between host snout-vent length and parasite intensity for female but not male hosts. Monthly prevalence of A. hylae reached a peak of 58% in April, but never dropped below 20% in any month; mean abundance peaked March-May, whereas few worms were recovered in December and January. Confirming a parasitic lifestyle, wild-collected hosts with intense infections, typically >40 worms, showed obvious dilatation of the ureter wall, and some young-of-the-year O. septentrionalis exposed to A. hylae in the laboratory were killed by the apparent rupture of the host's ureter. The worm has a direct life cycle: worms expelled in the host's urine are capable of locating and re-infecting other hosts within aquatic microhabitats such as bromeliad tanks, and worms can survive for weeks in a free-living environment, even undergoing a morphological change. Further, chemotaxis assays found a positive response to a tree frog attractant for worms recently removed from hosts. Overall, this study provides the first multifaceted investigation on the life history and ecology of any Allodero spp., which offers new insights into an understudied endoparasitic oligochaete.

A new embryonic pattern in parasitic wasps: divergence in early development may not be associated with lifestyle

Comparative embryogenesis of Encarsia formosa and Encarsia pergandiella (Hymenoptera Aphelinidae), two endoparasitoids of whiteflies (Hemiptera Aleyrodidae), revealed two strongly diverging developmental patterns. Indeed, the centrolecithal anhydropic egg of E. formosa developed through a superficial cleavage, as it occurs in Nasonia vitripennis, Apis mellifera, and Drosophila melanogaster. In contrast, the alecithal hydropic egg of E. pergandiella developed through holoblastic cleavage within a specialized extra-embryonic membrane (EEM). Since this developmental pattern evolved independently in several lineages of hymenopteran endoparasitoids, departures from the superficial cleavage mode have been argued to be strongly canalized in response to a shift from ecto- to endoparasitic lifestyle. Coexistence of both developmental patterns in two congeneric species suggests that alterations of early embryonic development may not be correlated with lifestyle. In addition, embryogenesis of E. pergandiella exhibited the following developmental novelties compared to other species possessing a hydropic egg: (i) polar body derivatives early acquired a cytoskeletal boundary prior to any other cellularization event; (ii) cellularization was asynchronous, starting with an early differentiation of a single apical blastomere at the end of the third cleavage; (iii) appearance of cytoskeletal boundaries of embryo blastomeres occurred between the third and fourth cleavages; (iv) the EEM originated through asynchronous participation of three separate lineages of cleavage nuclei, one of which associated with the polar body derivatives in a syncytium. Our results confirm a scenario of high plasticity in the early developmental strategies of hymenopteran endoparasitoids.

A novel microhabitat for parasitic copepods: A new genus of Ergasilidae (Copepoda: Cyclopoida) from the urinary bladder of a freshwater fish

An endoparasitic copepod is reported from the urinary bladder of a fish for the first time. Endoparasitic copepods on fish hosts are extremely rare and the impact of colonization of this novel microhabitat on the biology of the parasite is discussed. This curious association was reported from two different host families of Neotropical freshwater fishes, Erythrinidae and Cichlidae, collected from the Cristalino River, a tributary of the Araguaia River, in Brazil. The copepod is fully described using light and scanning electron microscopy. Urogasilus brasiliensis n. g., n. sp. represents a new genus and species of the family Ergasilidae and can be distinguished from other genera by its unique tagmosis, in which the fourth and fifth pedigerous somites and the genital double-somite are all fused to form an elongate trunk. The anal somite is the only free abdominal somite present. The pattern of leg segmentation is also unique, with legs 1 to 3 each having a 2-segmented endopod and leg 4 reduced to a single seta. The discovery of ovigerous female ergasilids in the urinary bladder of a fish is novel and this discovery represents a good model for further studies on the adaptations to an endoparasitic lifestyle.

Hyposoter didymator uses a combination of passive and active strategies to escape from the Spodoptera frugiperda cellular immune response

An endoparasitic life style is widespread among Hymenoptera, and various different strategies allowing parasitoids to escape from the host encapsulation response have been reported. Species carrying polydnaviruses (PDVs), such as the ichneumonid Hyposoter didymator, generally rely on the viral symbionts to evade host immune responses. In this work, we show that H. didymator eggs can evade encapsulation by the host in the absence of calyx fluid (containing the viral particles), whereas protection of the larvae requires the presence of calyx fluid. This evasion by the eggs depends on proteins associated with the exochorion. This type of local passive strategy has been described for a few species carrying PDVs. Immune evasion by braconid eggs appears to be related to PDVs or proteins synthesized in the oviducts being associated with the egg. We report that in H. didymator, by contrast, proteins already present in the ovarian follicles are responsible for the eggs avoiding encapsulation. Mass spectrometry analysis of the egg surface proteins revealed the presence of host immune-related proteins, including one with similarities with apolipophorin-III, and also the presence of three viral proteins encoded by IVSPERs (Ichnovirus Structural Protein Encoding Regions).

An Overview of Pentastomiasis in Reptiles and Other Vertebrates

Pentastomes are wormlike arthropods uniquely adapted to an obligate endoparasitic lifestyle in the respiratory tract of terrestrial vertebrates. The overwhelming majority of pentastome species infect the lungs of reptiles. The life cycle of these arthropods usually involves at least one intermediate host. Pentastomes carry zoonotic potential, but among those parasitizing reptiles only Armillifer spp. have been unquestionably associated with accidental human infections. Recent evidence suggests that pentastomes are crustaceans closely related to branchiurans, therefore therapeutic agents targeting fish lice should be investigated for their use in treating pentastome-infected reptile patients.