Description of Meloidoderita salina sp. n. (Nematoda, Sphaeronematidae) from a micro-tidal salt marsh at Mont-Saint-Michel Bay in France

• Published in: ZooKeys Vol. 249; no. 249; pp. 1 - 26
• Main Authors: Ashrafi, Samad, Mugniéry, Didier, van Heese, Evelyn Yj, van Aelst, Adriaan C, Helder, Johannes, Karssen, Gerrit
• Format: Journal Article
• Language: English
• Published: Bulgaria Pensoft Publishers 01-01-2012; Pensoft
• Subjects: atriplex-portulacoides l; Body length; criconematidae; Eggs; family heteroderidae; gene-sequences; Life Sciences; mixed models; New species; Nucleotide sequence; Pharynx; Phylogeny; Physical characteristics; Ribosomal DNA; ribosomal-rna; root-knot nematode; Roundworms; Salt marshes; Spicules; Tails; tylenchida; tylenchoidea; tylenchulidae; Uterus; Zoology; France; new species; halophyte; nematode; morphology; sea purslane; SEM; SSU rDNA; taxonomy; Atriplex portulacoides; cystoid; morphometrics; hexagonal; FAMILY HETERODERIDAE; MIXED MODELS; TYLENCHIDA; CRICONEMATIDAE; RIBOSOMAL-RNA; GENE-SEQUENCES; TYLENCHOIDEA; ROOT-KNOT NEMATODE; ATRIPLEX-PORTULACOIDES L; TYLENCHULIDAE
• ISSN: 1313-2989; 1313-2970
• DOI: 10.3897/zookeys.249.4138

Meloidoderita salinasp. n. is described and illustrated from the halophytic plant Atriplex portulacoides L. (sea purslane) growing in a micro-tidal salt marsh in the Mont-Saint-Michel Bay in France. This new species is the first member of Meloidoderita Poghossian, 1966 collected from a saline environment, and is characterized by the following features: sedentary mature females having a small swollen body with a clear posterior protuberance; slightly dorsally curved stylet, 19.9 µm long, with posteriorly sloping knobs; neck region irregular in shape and twisted; well developed secretory-excretory (S-E) pore, with markedly sclerotized S-E duct running posteriorly; prominent uterus bordered by a thick hyaline wall and filled with eggs. The adult female transforms into a cystoid. Eggs are deposited in both egg-mass and cystoid. Cystoids of Meloidoderita salinasp.n. display a unique sub-cuticular hexagonal beaded pattern. Male without stylet, pharyngeal region degenerated, S-E duct prominent, deirids small, developed testis 97.5 µm long, spicules 18.4 µm long, cloacal opening ventrally protruded, small phasmids posterior to cloaca opening and situated at 5.9 (3.2-7.7) µm from tail end, and conical tail ending in a rounded terminus marked with one (rarely two) ventrally positioned mucro. Additionally, some young malesof the new species were observed enveloped in the last J2 cuticle. Second-stage juvenile body 470 µm long, with a 16.4 µm long stylet, prominent rounded knobs set off from the shaft, hemizonid anterior and adjacent to S-E pore, small deirids located just above S-E pore level, genital primordium located at 68-77% of body length, phasmids small and located at about 19 µm from tail tip, and tail 38.7 µm long, tapering to finely pointed terminus with a finger-like projection. Phylogenetic analyses based on the nearly full length small subunit ribosomal DNA sequences of Meloidoderita salinasp. n. revealed a close relationship of the new species with Sphaeronema alni Turkina & Chizhov, 1986 and placed these two species sister to the rest of Criconematina.