Akanthomyces araneogenus Z.Q. Liang, W.H. Chen & Y.F. Han, Phytotaxa 379(1): 69 (2018)

Wang, Yao, Wang, Zhi-Qin, Luo, Run, Souvanhnachit, Sisommay, Thanarut, Chinnapan, Dao, Van-Minh & Yu, Hong, 2024, Species diversity and major host / substrate associations of the genus Akanthomyces (Hypocreales, Cordycipitaceae), MycoKeys 101, pp. 113-141 : 113

Akanthomyces araneogenus Z.Q. Liang, W.H. Chen & Y.F. Han, Phytotaxa 379(1): 69 (2018)

Fig. 6

Akanthomyces tiankengensis W.H. Chen, Y.F. Han, J.D. Liang & Z.Q. Liang, Microbiology Spectrum 10(5): e01975-22, 6 (2022). Synonym.

Description.

Sexual morph: Undetermined. Asexual morph: Mycosed hosts covered with white to pale yellow mycelia, occasionally several synnemata arising from all of the parts of the host. Colonies on PDA moderately fast-growing at 25 °C, reaching a diameter of 25-36 mm in 14 days at 25 °C, circular, middle bulge, white to yellowish, reverse yellowish. Hyphae smooth-walled, branched, septate, hyaline, 0.5-2.9 μm wide. Conidiophores smooth-walled, cylindrical, solitary, 10.6-22.4 × 1.3-2.6 μm (n = 30). Phialides consisting of a cylindrical, somewhat inflated base, verticillate on conidiophores, usually in whorls of 2-3 or solitary on hyphae, 8.1-17.8 × 1.1-3.6 μm (n = 30). Conidia smooth and hyaline, one-celled, globose, 1.6-2.4 μm in diameter or ellipsoidal to fusiform, 2.2-4.1 × 1.1-2.3 μm (n = 50), often in chains. Size and shape of phialides and conidia similar in culture and on natural substratum.

Host.

Spider ( Araneae ).

Habit.

On the spiders on dead stems or emerging from leaf litter.

Distribution.

Guizhou and Yunnan Province, China; Chiang Mai Province, Thailand; Nghe An Province, Vietnam.

Material examined.

Thailand, Chiang Mai Province , Chiang Mai City , Queen Sirikit Botanic Garden (18.8990°N, 98.8604°E, 547 m above sea level), on a spider on a dead stem, 20 November 2018, Yao Wang (YHH 2301001; living culture: YFCC 1811934). VIETNAM, Nghe An Province, Pu Mat National Park (18.9292°N, 104.5889°E, 621 m above sea level), on spiders emerging from leaf litter on the forest floor, 28 April 2017, Yao Wang (YHH 2301007, YHH 2301012; living culture: YFCC 1704946, YFCC 1704947). China , Yunnan Province , Dai Autonomous Prefecture of Xishuangbanna , Mengla County (21.1817°N, 101.7252°E, 875 m above sea level), on a spider on a dead stem, 12 June 2022, Zhi-Qin Wang (YHH 2301002; living culture: YFCC 2206935) .

Commentary.

In our phylogenetic analyses, Akanthomyces araneogenus ex-type strain (GZUIF DX2) and A. tiankengensis ex-type isolate (KY11571) and our two samples isolated from the spiders formed a well-supported clade (Fig. 1 ). From a phylogenetic point of view, A. tiankengensis could not be distinguished from A. araneogenus , being inside the clade of the latter. Previous morphological observations revealed several differences in the characteristics between A. araneogenus and A. tiankengensis ( Chen et al. 2018; Chen et al. 2022); however, our samples from different regions showed diversity of morphology in this study. The colony colour and the shape and size of the phialides and conidia of A. araneogenus and A. tiankengensis , amongst other morphological features, have been noted in our samples. There is reason to believe that distinguishing the two species is difficult because of the extensive overlap in morphological characteristics. Thus, we propose that A. tiankengensis is a synonym of A. araneogenus .

Figures

Figure 1. Phylogenetic tree of Akanthomyces species, based on combined partial ITS + nrLSU + TEF + RPB 1 + RPB 2 sequences. Numbers at the branches indicate support values (BI-PP / IQ-TREE-BS / RAxML-BS) above 0.7 / 70 % / 70 %. Ex-type materials are marked with " T ". Isolates in bold type are those analysed in this study.

Figure 6. Morphology of Akanthomyces araneogenus A fungus on spider B conidiogenous structures on the host C, D culture character on PDA medium E-H conidiophores, conidiogenous cells and conidia I conidia. Scale bars: 5 mm (A); 30 µm (B); 30 mm (C, D); 10 µm (E); 5 µm (F-I).