Fungal and Rickettsial Infections of Some East Asian Trapdoor Spiders
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45 European Arachnology 2000 (S. Toft & N. Scharff eds.), pp. 45-49. © Aarhus University Press, Aarhus, 2002. ISBN 87 7934 001 6 (Proceedings of the 19th European Colloquium of Arachnology, Århus 17-22 July 2000) Fungal and rickettsial infections of some East Asian trapdoor spiders JOACHIM HAUPT Technische Universität Berlin, FR 1-1, Franklinstr. 28/29, D-10587 Berlin, Germany ([email protected]) Abstract While published data on fungal and rickettsial infections of spiders give the impression of a wide range of hosts infected by particular agents, field collections of trapdoor spiders from East Asia reveal a clear distinction: representatives of Mesothelae were infected by rickettsiae, while speci- mens of the genus Latouchia (Mygalomorphae, Ctenizidae) were found to be infected by the hypho- mycete fungus Nomuraea atypicola. Key words: Mesothelae, Ctenizidae, infection, Rickettsiales, Nomuraea INTRODUCTION morphological studies. The determination of Mesothelae have not been spared by predators, mesothele spiders is according to Haupt (1983). parasites and diseases. Besides ravaging ani- Specimens of Latouchia were only determined mals like skinks and centipedes which regu- to the rank of genus which is sufficient for the larly come across those soil dwelling spiders, present work. The fungus Nomuraea atypicola there are reports on parasitic laelapid mites like (Yasuda, 1915) Samson, 1974 (syn. Isaria atypi- Liunghia bristowei Finnegan, 1933 living on cola, Cordyceps atypicola) (Deuteromycotina: Hy- Liphistius malayanus Abraham, 1923 and there phomycetes) was identified according to Koba- are parasitic flies and wasps (Sawaguti and Ozi yasi (1982). Rickettsiales could only be identi- 1937; Bristowe 1976; Schwendinger 1990) which fied as an order, according to the electron mi- attack Mesothelae along with other spiders. croscopic appearance of the cells. Mesothelae are also subject to parasitation by As in several species the collected material mermithid nematodes (pers. obs.). was quite numerous, it represented a good oc- Infections found in some species of Meso- casion to study the prevalence of different thelae are compared to those in other trapdoor pathogens. The present study was carried out spiders of the genus Latouchia (Mygalomor on living spiders, except for Nomuraea infec- phae: Ctenizidae). tions in which the perithecial stroma grows out from the dead spider and opens the trapdoor MATERIAL AND METHODS from inside the burrow, thus indicating the in- Specimens of Mesothelae and Ctenizidae fection. (genus Latouchia) collected in Kyushu, in Oki- Trapdoor spiders live inside their burrows nawa and in Malaysia were brought to the in moist soil, therefore the observer easily laboratory and kept there for ethological and misses the date when a specimen dies. In the 46 European Arachnology 2000 Fig. 1. Electron microscopic section through the opisthosoma of Liphistius malayanus cameroni with intestinal cells (I) and rickettsiae in intermediate cell (R). P: vacuoles containing protein, V: vacuoles. Scale 10 µm. Fig. 2. Perithecial stroma of Nomu- raea atypicola emerging from the burrow of Latouchia sp. (Cte- nizidae) by opening the trapdoor from inside. Scale 2 mm. moist environment dead spiders may become tions (1 µm) were stained with Kristallviolett infected secondarily by fungi from the soil: (Merck). Specimens of Nomuraea atypicola were such cases were not studied in the present deposited in the Botanical Museum, Berlin. paper. For light microscopic study, the opistho- RESULTS soma of infected specimens was submersed in Histological and electron microscopic results Bouin’s fluid and embedded in paraplast. Sec- In Mesothelae, rickettsial infection is very obvi- tions were stained with Haematein, Azan or ous in the intermediate cells of the hepatopan- Haematoxylin/Chromotrop after Dobell. Pro- creas (Fig. 1), while neighbouring cells of the cedures for electron microscopy were as de- midgut remain uninfected. The intermediate scribed previously (Haupt 1996), semi-thin sec- tissue is known to function as storage organ Haupt: Fungal and rickettsial infections 47 Table 1. Number of specimens of Mesothelae and Latouchia (Ctenizidae) collected (N) compared to those infected by different pathogens. Infected by N Rickettsiales Nomuraea % Heptathela kimurai kimurai (Kishida, 1920) 52 1 - 1.9 Heptathela kimurai yanbaruensis Haupt, 1983 164 3 - 1.8 Ryuthela nishihirai nishihirai (Haupt, 1979) 199 3 - 1.5 Liphistius malayanus cameroni Haupt, 1983 134 6 - 4.5 Latouchia sp. 22 - 4 18.2 analogous to the fat body of insects. Mainly production. Generally, this stalk, the perithecial lipids and glycogen are found in these cells stroma, grows along the burrow, opens the (Ludwig & Alberti 1988), but the histological trapdoor from inside, and reaches a height of study also reveals numerous vesicles contain- 20 to 30 millimeters. In the upper part it bears ing protein. numerous purple ascospores (Fig. 2), which The first rikettsial stages to be detected are now, outside the spider’s burrow, are subject to narrow and electron dense. Apparently, they aerial dispersal. grow inside the host cells to form larger, less Instead, during 20 years of breeding Meso- electron dense cells. This stage may or does thelae, out of 549 specimens taken from the undergo binary fission thus multiplying the field not a single one was found to be infected parasitic population in the host cell. Finally, all by Nomuraea atypicola. intermediate cells in the hepatopancreas are filled with nothing but rickettsial cells: all or- Infection rates ganelles and even the nuclei have disappeared. There are regular infections by Rikettsiales in Apparently, the rikettsiae use up the storage Mesothelae (Table 1) found in Kyushu, Ryu- products for their own purpose, and moulting kyu, or Malaysia. The infection rate must be becomes impossible for the spider. considered low, as far as most localities are These later stages of infection can be recog- concerned. Nevertheless, when comparing in- nized easily by the whitish opaque opistho- fection rates of the same species from different soma of host spiders, which is typical for localities, there were striking differences: rikettsial infections. Finally, the intermediate Rickettsial infection rates of Ryuthela nishihirai cells rupture and as the spider dies and the nishihirai were almost 6% (n = 52) in Suyeyoshi, whole opisthosoma dissolves, the pathogens Naha, Okinawa, but almost negligible in Ryu- spread into the soil. In this final phase the tan, Naha, Okinawa. Both places, only a few opisthosoma is so inflated that dissection be- kilometers from each other, are or were resi- comes impossible. Even a careful touch results dues of rather natural habitats with similar soil in the disruption of the cuticle and a milky conditions, but the locality in Suyeyoshi is situ- fluid appears from inside. ated in a valley of a brooklet, while Ryutan is So far, no experimental infection of Meso- close to a hill top, more exposed to wind and thelae along with food has been successful. this place appears much drier. The other group of trapdoor spiders, living Trapdoor spiders of the genus Latouchia in the same habitats, belongs to the genus La- (Ctenizidae) were infected by the hyphomycete touchia (Ctenizidae). Among them, one may Nomuraea atypicola, and to a much larger de- regularly observe infections by the fungus No- gree. The 22 specimens of Latouchia proved to muraea atypicola. Its hyphae grow through the be infected at a rate of about 18%. whole body of the spider and finally, within a few hours, form a long stalk with conidium 48 European Arachnology 2000 DISCUSSION are most likely to be infected (Federici 1984), Many fungal infections have been described in which is in line with our observations on connection with spiders (Evans & Samson Ryuthela nishihirai. 1987), but unfortunately, in many cases either The wide distribution does not automati- the spider or the fungus remained undeter- cally allow any conlusion on specific identity. mined. The hyphomycete fungus Nomuraea At present it seems doubtful whether patho- certainly occurs in a wide range of soil dwell- genic Rickettsiales represent only one species. ing mygalomorphs, and it has also been found Transmission of Rickettsiales from a scorpion in araneomorph spiders (for literature, see to other arachnids, even to members of other Coyle et al. 1990). In North America a broad scorpion families, turned out to be impossible range of spider species could be infected ex- (Morel 1978). Our studies on infections of trap- perimentally by an isolate of Nomuraea from door spiders point to the same direction. The ascospores originating from an infected Brazil- redefinition of the group based on serological ian trapdoor spider. By applying a conidial sus- data has been strongly suggested previously pension containing a detergent, 20 out of 27 (Louis et al. 1977). spider species were successfully infected In general, the infection rate with (Greenstone et al. 1987). In Okinawa, on the Rickettsiales is low. A 5% infection rate in scor- other hand, infectious diseases in trapdoor spi- pions (Morel 1976) is well in line with our re- ders seem to be clearly linked to different fami- sults. Such low prevalence of infection may lies: while Latouchia (Ctenizidae) specimens also be the reason that early stages of infections were found to be infected by Nomuraea atypi- are hardly found in the intermediate cells of cola, rickettsial infections were limited to Meso- free-living Mesothelae;