Aporcelaimellus crassus, Andrássy, 2009

Andrássy, I., 2009, Free-living Nematodes from Albania, including the description of three new species, Nematologia Mediterranea 37, pp. 73-88 : 83

APORCELAIMELLUS CRASSUS sp. n.

( Fig. 6 )

Holoype female. L = 2.38 mm; a = 21; b = 4.6; c = 46; c’ = 1.2; V = 48%.

Females (n = 4). L = 2.30-2.62 mm; a = 21-23; b = 4.1-4.5; c = 41-49; c’ = 1.1-1.3; V = 47-51%.

General description. A robust nematode of large size; body 94-115 µm wide at mid-region. Cuticle smooth and thick, 4-6 µm on mid-body and 6-8 µm on tail, consisting of the usual two layers (under light microscope): an out-er, thinner and transparent and an inner, “darker” (not transparent) and thicker layer. Labial region 19-21 µm wide, somewhat sunk and strongly separated from adjacent body by a deep constriction. Body at posterior end of oesophagus 4.2-5.3 times as wide as head. Amphid about as wide as half the corresponding body width. Odontostyle relatively short, 24-26 µm, 1/20-1/24 of oesophagus length, about 1.2 times as long as labial width, thicker than cuticle at same level. Aperture occupying more than half of stylet length. Guiding apparatus aporcelaimoid, dorsally thicker than ventrally. Oesophagus 480-625 µm long, widened somewhat before its middle. Distance between posterior end of oesophagus and vulva 1.1-1.2 times as long as oesophagus. Oesophageal gland nuclei, because of the heavy muscular tissue, moderately distinct. Dorsal nucleus located at 51- 57% of oesophagus length or at 12-13% of entire length of body. AS1 = 21-24%, AS2 = 45-48%, PS1 = 70-72%, PS2 = 72-73%. Glandularium 220-235 µm long.

Female. Vulva transverse with strongly sclerotized inner lips; vagina 40-42 µm, occupying less than half of corresponding body diameter. Gonads quite short, each 2.2-2.5 body widths long or occupying 9-12% of body length. Uterine egg not observed; no spermatozoa in uterus. Pre-rectum 2.5-3.0, rectum 1.2-1.4 anal body widths long. Vulva-anus distance equal to 20-25 tail lengths. Tail 40-58 µm long or 2.0-2.3% of total body length, as long as or a little longer than anal body diameter, straight, distinctly concave on its dorsal contour and rounded on tip. Outer layer of cuticle (along with the terminal lacuna) thicker than inner layer.

Male. Not found.

Main characters and relationships. Body large and plump, head strongly offset with sunken lips, odontostyle short with large aperture, female genital tract short, tail somewhat longer than anal body diameter, concave on dorsal contour and narrowly rounded on tip.

In several morphological structures the new species is most closely related to Aporcelaimellus alius Andrássy, 2002 , which was described from sedge roots and wet grassy soil in the Fertő-Hanság National Park, Hungary (Andrássy, 2002). Aporcelaimellus crassus can be distinguished from its relative by the longer and thicker body (2.3-2.6 vs. 1.8-2.2 mm long; 94-115 vs. 82-90 µm wide at middle), somewhat longer odontostyle (24-26 vs. 21-23 µm), longer pre-rectum (2.5-3.0 vs. 1.5-2.2 anal body widths), and particularly by the shape of the tail. The latter is longer and more conoid (c’ = 1.1-1.3 vs. 0.7-1.0) and narrowly rounded on tip (vs. rather broadly rounded).

Type specimens. Holotype female on slide No. 14953. Paratypes: six females and three juveniles. All in the collection of the author.

Type habitat and locality. Periferi Mat, Quafa e Shtamës, 22 km from Burrel along the road to Krujë, 1240 m asl; soil from a natural beech forest, collected in October, 2004 by J. Kontschán.

Etymology. From the Latin crassus = thick or fat.

Figures

Fig. 6. Aporcelaimellus crassus sp. n. A: anterior end; B: vulval region; C-D: female posterior ends. (Scale bars 20 µm each).