Chitonomyces paradoxus (Peyr.) Thaxt.

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 106

Chitonomyces paradoxus (Peyr.) Thaxt.

MB#170184

Fig. 21E

Memoirs of the American Academy of Arts and Sciences 12: 287 ( Thaxter 1896: 287). – Basionym: Heimatomyces paradoxus Peyr., Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften. Wien. Mathematisch-naturwissenschaftliche Classe. Abteilung 1 68: 251 ( Peyritsch 1873) [MB#249906]. –

Type: [Not designated] [Ind. loc.] [Type lost?!] “Mit der vorhergehenden Art auf Laccophilus minutus Sturm und L. hyalinus Degeer ”. [ Austria]

Heimatomyces unciger Thaxt. ( Thaxter 1895: 478, as uncigerus) [MB#245659]. – Chitonomyces unciger (Thaxt.) Thaxt. ( Thaxter 1896: 288, as uncigerus) [MB#175610]

Chitonomyces truncatus Speg. ( Spegazzini 1915b: 47) [MB#176303]

Diagnostic features

The ascogenous cavity inside the perithecium appears nearly horizontal, strongly curved, u-shaped. The ostiole is surrounded by obtuse, usually prominent and asymmetrical lips ( Fig. 21E , *). The perithecium bears a variably elongated horn-like outgrowth arising from the upper outer wall cell of the anterior row. [Detailed descriptions: Thaxter 1916, 1924; Sugiyama 1973; Majewski 1994b; Santamaria 2001b, 2003; De Kesel & Werbrouck 2008; Goldmann & Weir 2012]

Distribution and hosts

More common than Ch. melanurus with which it often coexists on the same host individual, occupying a similar position but just below it. Reported on Laccophilus (Col. Dytiscidae ) in America: Grenada, Jamaica, USA, Trinidad & Tobago ( Santamaria et al. 1991), Bahamas ( Haelewaters et al. 2017); Asia: Indonesia, Japan, Taiwan, Thailand ( Santamaria et al. 1991), Korea ( Lee & Kim 1990), China ( Lee et al. 1995), Turkey ( Rossi 2016), Cambodia ( Try et al. 2017); Africa: Sierra Leone ( Rossi & Leonardi 2018); and Europe: Austria (type), Finland, France, Germany, Hungary, Italy, Poland, Russia, Spain, United Kingdom, former Yugoslavia ( Santamaria et al. 1991), Belgium ( De Kesel & Werbrouck 2008), Sweden ( Huggert 2010).

Collections examined from Denmark

On Laccophilus minutus (Linnaeus, 1758) (Col. Dytiscidae )

DENMARK – Bornholm (B) • Raghammer Odde ; 55°1.193′ N, 14°55.777′ E; VA99; 22 Jun. 2018; JP 1146; JP det.; ZMUC C-F-123668 . – Nordvestsjaelland (NWZ) • Klintebjerg ved Klint ; 55°57.321′ N, 11°34.197′ E; PH60; 16 Oct. 2017; JP 589; JP det.; ZMUC C-F-123078 . – Vestjylland (WJ) • Simmelmose ; 55°46.299′ N, 9°3.519′ E; NG08; 2 Jun. 2019; JP 1478; JP det.; ZMUC C-F-124063 .

Remarks

First record from Denmark. Three forms of this species may be perfectly distinguished by morphological traits, depending on the hosts, being Laccophilus minutus , L. poecilus (= L. variegatus ) and L. hyalinus . These forms were described and illustrated by Majewski (1994b) and Santamaria (2001b, 2003). Further studies supported by molecular analysis might clarify the taxonomic position of these forms. Danish thalli belong to the form growing on L. minutus .

Figures

Fig. 21. A–B. Chitonomyces italicus Speg. A. Detail of cell IIIa and its outgrowth (arrow). B. Mature thallus. – C–D. Chitonomyces melanurus Peyr. C. Mature thallus showing perithecial enlarged lips (*). D. Young thallus with labelled cell IIIa and hooked basal cell of primary appendage (arrow). – E. Chitonomyces paradoxus (Peyr.) Thaxt. Mature thallus showing prominent perithecial lips (*). – F–G. Hydraeomyces halipli (Thaxt.) Thaxt. Mature thalli. Scale bars: 50 µm. Photographs from slides ZMUC C-F-124059 (A–B), ZMUC C-F-124062 (C), ZMUC C-F-123671 (D), ZMUC C-F-123078 (E), ZMUC C-F-122568 (F–G).