Description of Schistonchus superbus n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus superba in China

Abstract

A new nematode species was recovered from the syconia of Ficus superba from the South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong Province, China, during a survey of nematode biodiversity from 2007 to 2012. It is described herein as Schistonchus superbus n. sp. and is characterised by possessing the combined characters of a short post-uterine sac and digitate tail without a mucron in females, excretory pore located near the metacorpus, amoeboid sperm, a unique wedge-shaped male tail with variable tip and two pairs of subventral papillae, absence of a gubernaculum and possession of sickle-shaped spicules without a cucullus and with a thorn-shaped rostrum. Schistonchus superbus n. sp. is typologically differentiated from all other described species in this genus by the possession of a wedge-shaped tail in males and a digitate tail without mucron in females. Schistonchus superbus n. sp. was easily differentiated from other sequenced species by the partial small subunit rRNA gene (SSU), D3 expansion segment of the large subunit rRNA gene (LSU) and mitochondrial DNA subunit I (mtCOI). Phylogenetic analysis with partial SSU sequences suggests that S. superbus n. sp. is sister to S. caprifici and S. hirtus, and is a polyphyletic relative to other Schistonchus species that have been sequenced. Based on inferences using LSU D3 sequence data, S. superbus n. sp. is in a well-supported monophyletic clade with S. caprifici, S. hirtus and S. macrophylla.