Species Diversity and Distribution of Trichomycete Gut Fungi in Their Arthropod Hosts

毛菌是一种真菌，专门生活在许多节肢动物的内脏里，比如甲壳类动物、千足虫和昆虫。在大多数情况下，它们与宿主关系的本质尚不清楚，尽管有证据表明，其中一些真菌可以杀死宿主，而另一些真菌可能通过合成宿主所需的甾醇营养物质而对宿主有益。堪萨斯大学的Robert Lichtwardt博士是世界上为数不多的研究这些共生真菌的分类学和生物学的专家之一，正是他多年来的努力才使人们对这些真菌有了目前的认识。在对毛原菌的持续研究中，利希沃特博士正在调查它们在澳大利亚、新西兰和哥斯达黎加这两个相隔甚远的地区的水生宿主中的分布情况。他的初步工作表明，在这两个地区都出现了新的真菌物种，可能还有新的属，并且对它们的宿主具有不同程度的特异性。在受控的实验室条件下培养真菌的努力将继续进行，同时研究确定它们的完整生活史，包括真菌孢子扩散并感染适当宿主节肢动物的过程。Lichtwardt博士的研究还有助于编制世界上，特别是热带地区的微生物的清单，目前这份清单非常不完整。

Trichomycetes are fungi that live obligately within the guts of many kinds of arthropods such as crustaceans, millipedes, and insects. The nature of the relationship with their hosts is not known in most cases although there is evidence that some of these fungi can kill their hosts whereas others may benefit them by synthesizing sterol nutrients required by the host. Dr. Robert Lichtwardt of the University of Kansas is one of the few specialists in the world working on the taxonomy and biology of these commensalistic fungi, and it is his efforts over the years that have led to the present stage of knowledge about them. In continuing studies of Trichomycetes, Dr. Lichtwardt is surveying their occurrence in aquatic hosts in two widely separated regions, Australia and New Zealand and in Costa Rica. Preliminary work by him has indicated that new species of fungi, and possibly new genera, occur in both regions, and with varying levels of specificity toward their hosts. Efforts to culture the fungi under controlled laboratory conditions will continue, along with studies to determine their complete life history, including processes by which fungal spores are dispersed and come to infect appropriate host arthropods. Dr. Lichtwardt's studies also contribute to the inventory of microbial organisms in the world, especially of tropical regions, an inventory at present very incomplete.