Eubostrichopsis johnpearsei Ott & Pröts 2021, sp. n.
Creators: name: Ott, Jörg A.
name: Pröts, Philipp
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Adenophorea
Desmodorida
Desmodoridae
Eubostrichopsis
Eubostrichopsis johnpearsei

description: Eubostrichopsis johnpearsei sp. n.
(Figs. 2–5)
Type material: Holotype male, paratype female, other paratypes: male 2, females 2–3
Type specimens deposited in the collection of the Natural History Museum Vienna (Austria) Numbers Invertebrata varia Collection 5855 (holotype), 5856 (paratype male 2), 5857/1–3 (paratypes female 1–3). Type locality: Beach south of Yaquina Head, Newport (Oregon) (holotype male, paratype male 2, paratype female 1–2). Sampling date: April 25, 1986.
Other locality: beach in front of the Joseph M. Long Marine Laboratory, Santa Cruz (California) (paratype female 3). Sampling date: March 2, 1986.
Etymology: The species is named in honor of the late John Pearse, 1940–2020, eminent invertebrate biologist and the first author’s friend and generous host during his sabbatical at the University of California Santa Cruz 1985–86, when the specimens were collected.
Measurements. Table 1.
With the characters of the genus. Slender worms with a short pharynx and short tail. There are two circles of subcephalic setae on the cephalic capsule. Both the cephalic and subcephalic setae slightly curved inward. No somatic setae except for the precloacal region and tail of males. Cephalic capsule without block layer, surface largely unstriated, striation starting a few µm before level of posterior end of cephalic capsule. Striae 0.7–1 µm wide, striation extending over whole body, tip of tail with an unstriated terminal part, 15 µm long. Precloacal region of males with a medioventral membranous ridge, 340 µm (holotype) and 250 µm (paratype) long, 4 µm high, bearing a row of short (4 µm long) setae, 10–20 µm apart. Male tail with two pairs of thorn-like hollow setae (porids) at 40–47 and 75–80 % of tail length. Pharynx with cylindrical anterior part, spherical bulbus occupying 20 % of pharynx length, no cardia. Prominent nerve ring encircling pharynx directly anterior to bulbus. No excretory system present. Males monorchic, testis starting at midbody; spicular apparatus with prominent musculature. Females didelphic, amphidelphic, ovaries reflexed, anterior ovary left, posterior right of gut. Female 3 with two ripe eggs in each uterus 80 x 30 µm. Vulva not specially cuticularized, slightly posterior to midbody. Symbiont coat (Fig. 6) covers the whole striated part of the worms’ body. Bacteria are 7–10 µm long, in center of cell 0.7 µm wide, tapering towards poles. Bacteria appear to divide longitudinally. Thicker (1.4–1.6 µm) cells show a distinct longitudinal groove. Approximately 170 cells per 100 µm 2 of host surface. A 4 mm long worm therefore carries about 850 000 bacterial cells. Total volume of symbiotic coat is more than 90 % of host volume or almost half of holobiont volume.
description: Published as part of Ott, Jörg A. & Pröts, Philipp, 2021, Eubostrichopsis johnpearsei n. gen., n. sp., the first stilbonematid nematode (Nematoda, Desmodoridae) from the US West Coast, pp. 353-362 in Zootaxa 4949 (2) on pages 355-357, DOI: 10.11646/zootaxa.4949.2.8, http://zenodo.org/record/4636499