Enchodelus carpaticus, Ciobanu & Popovici & Guerrero & Santiago, 2010

Ciobanu, Marcel, Popovici, Iuliana, Guerrero, Pablo & Santiago, Reyes Peña-, 2010, Nematodes of the order Dorylaimida from Romania. The genus Enchodelus Thorne, 1939. 3. Species with rounded tail and long odontostyle, Nematology 12 (4), pp. 609-618 : 609-613

Enchodelus carpaticus ** sp. n.

( Figs 1 , 2 )

MATERIAL EXAMINED

Fourteen females from Mehedinţi Mountains, mostly in good condition, some becoming visibly flattened.

MEASUREMENTS

See Table 2.

DESCRIPTION

Female

Moderately slender nematodes of medium size, 1.59- 1.87 mm long. Habitus after fixation somewhat curved ventrad, adopting an open C shape. Body cylindrical, tapering towards both ends, but more so anteriorly. Cuticle 3.0-5.0 µ m thick in anterior region, 3.5-5.5 µ m at mid-body and 7.0-9.0 µ m on tail, its outer layer with very fine transverse striations and much thinner than inner one, especially at tail level. Lateral chord 6-8 µ m wide or occupying ca one-tenth (8-12%) of mid-body diam., lacking any particular differentiation. Lateral pores obscure, two or three dorsal and ventral moderately coarse pores present at odontostyle/odontophore level, other more or less distinct ventral pores present throughout body. Lip region more or less rounded, offset by a distinct depression, 2.4-3.1 times as broad as high, ca one-fourth (flattened specimens) to one-third (26-34%) of body diam. at neck base. Lips amalgamated, labial and cephalic papillae visible but barely protruding above cephalic contour. Amphid fovea cup-shaped, opening at level of labial depression, occupying 9.5-12.0 µ m or one-half to three-fifths of lip region diam. Cheilostom almost cylindrical, with thick walls. Odontostyle comparatively slender and long, 14-21 times as long as wide and 2.1- 2.5 times longer than lip region diam. or 2.3-2.8% of total body length, aperture small, 3.0-4.5 µ m long or 7-10% of total length. Odontophore 1.0-1.2 times as long as odontostyle, with very well developed flanges. Guiding ring double, located at 25-31 µ m or 1.4-1.7 lip region diam. from anterior end. Pharynx consisting of a slender but muscular anterior portion enlarging gradually, basal expansion 4.6-6.4 times as long as wide, 2.0 (flattened specimens) to 2.9 times body diam. at neck base, occupying ca two-fifths (39-45%) of total neck length. Pharyngeal gland nuclei located as follows: DN = 63-65; S 1 N obscure; S 2 N = 82-86. Cardia rounded conoid, nearly as long as wide, (8-13) × (9-14) µ m. Acell mass or chord, ca one body diam. long, present in dorsal position between cardia level and proximal end of anterior ovary. Genital system didelphic-amphidelphic, both branches equally and well developed, anterior 355- 474 µ m, posterior 337-456 µ m long. Ovaries relatively short, anterior 61-77 µ m, posterior 90-155 µ m long, in general not reaching sphincter level, oocytes first in two or more rows, then in one row. Oviduct 107-148 µ m long or 1.3-2.2 corresponding body diam., consisting of a slender portion with prismatic cells and a moderately developed pars dilatata with visible lumen. Sphincter prominent, located between oviduct and uterus. Uterus typically tripartite, i.e., consisting of a wider proximal region with distinct lumen followed by a narrower intermediate portion with narrow lumen surrounded by cluster of hyaline cells, ending with well developed spheroid pars dilatata distalis, 135-195 µ m or 2.0-2.9 corresponding body diam. long. Uterine eggs, observed only in one female, (90-92) × (40-44) µ m. Only one female observed to contain sperm inside uterus. Vagina extending inwards 37-47 µ m or one-half to three-fifths of body diam., pars proximalis longer than broad, (14-25) × (11-17) µ m, with straight walls, enveloped by distinct circular musculature, pars refringens with (in lateral view) two well developed, trapezoidal sclerotised pieces measuring (7.5-9.5) × (7.5- 9.5) µ m and with combined width of 16-19 µ m, pars distalis 2.5-3.5 µ m long, weakly sclerotised. Two cells (probably glands) clearly visible in several specimens on both sides of vulva, one anterior, one posterior. Vulva a transverse slit. Prerectum 4.1-6.6 and rectum 0.8-1.2 anal body diam. long. Tail short, rounded; inner cuticle layer bearing radial striations. Two pairs of subterminal caudal pores, one subdorsal, one practically lateral.

© Koninklijke Brill NV, Leiden, 2010

Also available online - www.brill.nl/nemy

* According to Coldea (1991, 1993) and Pop et al. (1973).

** According to the Romanian System of Soil Classification ( Conea et al., 1980).

Male

Not found, but certainly occurring because one fertilised female was observed in the material studied.

TYPE LOCALITY AND HABITAT

Mountainous grassland located at Padina Izvoarelor Valley-Piatra Cloşani , Mehedinţi Mountains (Southern Romanian Carpathians); site no. 4 in Table 1.

TYPE MATERIAL

Holotype female numbered “5” on slide 744 and six paratype females (749/1-4, 6-7) deposited inthe nematode collection of the Institute of Biological Research, Cluj-Napoca, Romania. Slide 749 containing seven paratype females numbered “1”-“3” and “5”-“8” deposited in the nematode collection of Departamento de Biología Animal, Biología Vegetal y Ecología, University of Jaén, Jaén, Spain.

DIAGNOSIS AND RELATIONSHIPS

The new species is distinguished by its body 1.59- 1.87 mm long, lip region offset by a marked depression and 17-20 µ m diam., odontostyle 39.5-47 µ m long and 2.1-2.5 lip region diam. or 2.3-2.8% of total body length, odontophore 42-51 µ m long and with distinct basal flanges, neck length 336-388 µ m long, pharyngeal expansion 136-167 µ m long or 39-45% of total neck length, presence of dorsal cell mass near cardia, female genital system amphidelphic, long tripartite uterus 144- 195 µ m or 2.2-2.9 corresponding body diam. long, pars refringens vaginae with two trapezoidal sclerotisations, V = 42-50, and female tail short and rounded (21-29 µ m long, c = 55-87, c ļ = 0.5-0.7).

In having an odontostyle 39.5-47 µ m long, very well developed flanges at the odontophore base and a tripartite uterus, the new species is very similar to E. macrodorus ( de Man, 1880) Thorne, 1939 and E. saxifragae Popovici, 1995 . It differs from both in one subtle but reliable feature, the presence of a dorsal cell mass or chord between the cardia and the proximal end of the anterior ovary, a feature confirmed in all of the 14 specimens of the new species examined but never reported in E. macrodorus and E. saxifragae . Moreover, it can be distinguished from E. macrodorus by its longer pharyngeal expansion (136-167 µ m or 39-45% of total neck length vs 111-138 µ m or 33-38% of total neck length, although some variability is found in this character in E. macrodorus , see below), more posterior vulva with V = 42-50 (but less than 44 in only two specimens out of 14) vs 40-44 in both type and Romanian populations) and longer tripartite uterus (144-195 vs 56-143 µ m or 2.2-2.9 vs or 0.9-2.0 corresponding body diam. long) with well differentiated (vs barely differentiated) intermediate region; and from E. saxifragae in its shorter female body (L = 1.59-1.87 vs 1.96-2.35 mm in type population, n = 6; L = 1.80- 2.38 in Iberian populations, n = 37) and lip region offset by depression vs constriction. It also resembles E. groenlandicus ( Ditlevsen, 1927) Thorne, 1939 (see redescription by Guerrero et al., 2008), but can be separated in having the lip region offset by a well marked depression vs almost continuous or offset by weak depression, shorter odontostyle of 43.3 (39.5-47) vs 49.3 (44-53) µ m, shorter total stylet length (84-96 vs 94-108 µ m) and longer pharyngeal expansion (136-167 vs 112-142 µ m or 39-45 vs 31-39% of total neck length).

Figures

Fig. 1. Enchodelus carpaticus sp. n. A: Female, entire; B: Anterior region in median, lateral view; C: Lip region in surface, lateral view; D: Neck region; E: Female posterior region; F: Pharyngeal expansion; G: Vagina; H: Female genital system; I, J: Cell mass located in dorsal position between cardia level and proximal end of anterior ovary; K: Female caudal region.

Fig. 2. Enchodelus carpaticus sp. n. A: Female, entire; B, C: Anterior region in median, lateral view; D: Pharyngeal expansion; E: Neck region; F-H: Arrows point at cell mass located in dorsal position between cardia level and proximal end of anterior ovary; I: Female genital system; J: Female posterior region; K, L: Vagina (arrow indicates advulval cells); M: Female caudal region. (Scale bars: A = 200 µm; B-D, F-H = 20 µm; E, I, J = 50 µm; K-M = 10 µm.)