Two new species of the genus Sectonema Thorne, 1930 (Nematoda, Dorylaimida, Aporcelaimidae) from Iran, with new insights into its evolutionary relationships
M. Keramat, Z. Mahboubi, M. R. Atighi, E. Pourjam, P. Castillo, M. Pedram, R. Peña-Santiago
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引用次数: 0
Abstract
Two new species of the genus Sectonema found in northern Iran are characterized, including morphological descriptions and molecular (18S-, 28S-rDNA) analyses. Sectonema tehranense sp. nov. is distinguished by its 7.22 – 8.53 mm long body, lip region offset by constriction and 24 – 31 μm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, mural tooth 15.5 – 17 μm long at its ventral side, neck 1091 – 1478 μm long, pharyngeal expansion occupying 61 – 71% of the total neck length, female genital system diovarian, uterus simple and 3.9 – 4.2 times the corresponding body diameter long, transverse vulva (V = 49 – 59), tail short and rounded (44 – 65 μm, c = 99 – 162, c’ = 0.6 – 0.8), spicules 111 – 127 μm long, and 7 – 10 spaced ventromedian supplements with hiatus. Sectonema noshahrense sp. nov. displays a 4.07 – 4.73 mm long body, lip region offset by constriction and 23 – 25 μm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, odontostyle 14 – 14.5 μm long, neck 722 – 822 μm long, pharyngeal expansion occupying 66 – 68% of the total neck length, female genital system diovarian, uterus simple and 2.4 – 2.7 times the corresponding body diameter long, transverse vulva (V = 54 – 55), tail convex conoid (39 – 47 μm, c = 91 – 111, c’ = 0.8 – 0.9), spicules 82 μm long, and seven spaced ventromedian supplements with hiatus. Molecular analyses confirm a maximally supported (Epacrolaimus + Metaporcelaimus + Sectonema) clade and a tentative biogeographical pattern, with sequences of Indolamayan taxa forming a clade separated from those of Palearctic ones. Parallel or convergent evolution processes might be involved in the phylogeny of the species currently classified under Sectonema. This genus is certainly more heterogeneous than previously assumed.
期刊介绍:
Journal of Helminthology publishes original papers and review articles on all aspects of pure and applied helminthology, particularly those helminth parasites of environmental health, medical or veterinary importance. Research papers on helminths in wildlife hosts, including plant and insect parasites, are also published along with taxonomic papers contributing to the systematics of a group. The journal will be of interest to academics and researchers involved in the fields of human and veterinary parasitology, public health, microbiology, ecology and biochemistry.