Description of Deladenus brevis n. sp. (Sphaerularioidea: Neotylenchidae) from Iran: a morphological and molecular phylogenetic study

Abstract

Deladenus brevis n. sp. is described and illustrated based upon its morphological, morphometric, and molecular characters. The new species is mainly characterized by its small body size (367-454 µm long females and 350, 391 µm long males) and has small lateral vulval flaps. It is further characterized by having six lines in the lateral fields, cephalic region slightly expanded, narrower adjacent to the body, short 6 to 7 µm long stylet with three posteriorly sloped knobs, no post-vulval uterine sac (PUS), conical tail, narrowing to a rounded tip, and rare males with slender tylenchoid spicules and bursa reaching the tail tip. By having six lines in the lateral fields, the new species was compared with five known species of the genus, namely D. apopkaetus, D. cocophilus, D. durus, D. obtusicaudatus, and D. persicus, having comparable number (six or seven) of lines in the lateral fields. It was further compared with D. pakistanensis having lateral vulval flaps. The differences with above-mentioned species are discussed. In molecular phylogenetic analyses using nearly full length small and large subunit ribosomal DNA (SSU and LSU D2-D3 rDNA) and cytochrome c oxidase subunit I (COI mtDNA) gene sequences, D. brevis n. sp. formed clade with species of the genus with different clade support values in Bayesian inference.

Deladenus bonabensis n. sp. (Tylenchomorpha: Neotylenchidae) from East Azarbaijan province, northwestern Iran: A morphological and molecular phylogenetic study

“…A penial tube was observed in males of the new species. This structure is seen in light microphotographs of Deladenus nitobei Kanzaki, Tanaka Fitza, Kosaka, Slippers, Kimura, Tsuchiya & Tabata, 2016 as well. Based on available data, it seems that the genus is not monophylic in both SSU and LSU phylogenies, which is in agreement with previous studies (e.g., Heydari et al, 2020).…”

“…Based on available data, it seems that the genus is not monophylic in both SSU and LSU phylogenies, which is in agreement with previous studies (e.g., Heydari et al, 2020 ).…”

“…During this study, a population of the genus Deladenus was recovered from Ghara-Gheshlagh lagoon, Bonab, northwestern Iran. Previously, five species of this genus have been described or reported from Iran ( Jahanshahi Afshar et al, 2014 ; Miraeiz et al, 2017 ; Esmaeili et al, 2020 ; Heydari et al, 2020 ; Jalalinasab et al, 2020). The currently described new species could be conspecific with the previously sequenced species recovered from West Azarbaijan province, of which only three specimens were found (the isolate west.az) and sequenced in our lab (LSU accession numbers MW577121 and MW577120).…”

“…The list of valid species of the genus has already been given by several authors ( Siddiqi, 2000 ; Miraeiz et al, 2017 ; Yu et al, 2017 ; Morris et al, 2018 ). The two species D. gilanica Esmaeili, Jalalinasab, Ye, & Heydari, 2020 and D. brevis Heydari, Abolafia, & Pedram, 2020 are the most recent species added to the genus ( Esmaeili et al, 2020 ; Heydari et al, 2020 ).…”

“…In Iran, the genus was first recorded by reporting D. durus ( Jahanshahi Afshar et al, 2014 ). Afterward, the diversity of the genus was enriched by describing D. persicus Miraeiz, Heydari & Golhasan, 2017, D. gilanica , and D. brevis , all recovered from northern Iran ( Miraeiz et al, 2017 ; Esmaeili et al, 2020 ; Heydari et al, 2020 ). Herein, Deladenus bonabensis n. sp.…”