Gordionus bilaus, Begay, Alyssa C., Schmidt-Rhaesa, Andreas, Bolek, Matthew G. & Hanelt, Ben, 2012

Begay, Alyssa C., Schmidt-Rhaesa, Andreas, Bolek, Matthew G. & Hanelt, Ben, 2012, Two new Gordionus species (Nematomorpha: Gordiida) from the southern Rocky Mountains (USA), Zootaxa 3406, pp. 30-38 : 34-36

publication ID	https://doi.org/ 10.5281/zenodo.281865
DOI	https://doi.org/10.5281/zenodo.6170018
persistent identifier	https://treatment.plazi.org/id/03EE879C-FFEF-3D06-8EE2-FF09B53280C5
treatment provided by	Plazi
scientific name	Gordionus bilaus
status	sp. nov.

Treatment

Gordionus bilaus n. sp.

( Figs. 3 View FIGURE 3 , 4 View FIGURE 4 )

Holotype. MSB: PARA: 111. Male collected from a tributary of the North Fork of Tesuque Creek (35.7699, -105. 7954).

Paratypes. Allotype. MSB: PARA: 112. Female collected from a tributary of the North Fork Tesuque Creek (35.7699, -105.7954). Other paratypes. MSB: PARA 113–120

Etymology. The species epithet is derived from the Navajo word for fingers, ‘bila’, which describes the shape of spines surrounding the cloaca ( Fig. 3 View FIGURE 3 C).

Distribution. Rocky Mountains, Santa Fe National Forest, New Mexico. Found at two sites. The first site (site 1), is also where G. lokaaus n. sp. was found, (35.7699, -105.7954), at an elevation between 3,200‒3,290m. The second site (site 3) consisted of an unnamed first order stream (35.7970, -105.8028), flowing just to the northwest of the Santa Fe Ski Area. This smaller stream merges with the Rio en Medio and the exact collection site was situated in a large grassy meadow surrounded by aspen/pine woodlands at an elevation of 3,230m.

Type locality. Site 1 (35.7699, -105.7954).

Bionomics. The worms were collected in the free-living, post-parasitic, adult stage, and the paratenic and definitive hosts remain unknown. Adults of this species were collected from late June through early August.

Material examined. Thirty four worms (26 males, 8 females) were extracted, amplified, and sequenced. The anterior, posterior, and midsection of eight individuals were used for SEM.

Description of male. Adult males brown in color, with the exception of one individual which was white, and measuređ 55‒I26 (x = 87•O) mm lοng• Areοles οf οne type, mοstly flat; ranging in shape frοm pοlygοnal (Fig• 3D) to round ( Fig. 3 View FIGURE 3 E and F). Interareolar furrows are not as distinct as G. lokaaus n. sp., and in many areas areoles appear fused with neighboring areoles ( Fig. 3 View FIGURE 3 D, E, and F). Tubercles between areoles present in moderate quantity ( Fig. 3 View FIGURE 3 F). Rows of small precloacal bristles present in posterior end, which are branched ( Fig. 3 View FIGURE 3 H). Cloacal opening surrounded by broad bristles ( Fig. 3 View FIGURE 3 C) with a stout apex; some bristles appear to be branching. Bristles around cloaca arranged into 2‒3 rows ( Fig. 3 View FIGURE 3 C). Postcloacal spines begin immediately posterior to the cloacal bristles and extend to the inner-side of the tail lobes ( Fig. 3 View FIGURE 3 A). The shape of the postcloacal spines is mound-like and tall with a diameter of 4‒8µm ( Fig. 3 View FIGURE 3 B). Adhesive warts are present anterior to cloacal opening ( Fig. 3 View FIGURE 3 G), canoe-shaped, and relatively wide (12‒22µm).

Description of female. Adult females white in color, with one exception which was brown, and measured 59‒2OO (x = 73•I) mm lοng• Cuticle resembles that οf the male (Fig• 4A anđ B)• Tubercles are slightly lοnger anđ more abundant in the anterior end ( Fig. 4 View FIGURE 4 C).

Diagnoses and taxonomic comments. Several morphological characters clearly separate these two new species. The spines/bristles surrounding the cloaca are dense and form a tube-like structure in G. l o k a a u s n. sp. ( Fig. 1 View FIGURE 1 C) but are finger-like and much narrower in G. bilaus n. sp. ( Fig. 3 View FIGURE 3 C). The areoles are clearly defined by interareolar furrows in G. l o k a a u s n. sp. ( Fig. 2 View FIGURE 2 A–C) but appear almost fused by the absence of interareolar furrows in G. bilaaus n. sp. ( Figs. 4 View FIGURE 4 A–C). Adhesive warts are thin, triangular and 2-dimensional in G. l o k a a u s n. sp. ( Fig. 1 View FIGURE 1 B) but tall, stout, mound-like, and 3-dimesional in G. b i l a u s n. sp. ( Fig. 3 View FIGURE 3 B). Finally, the adhesive warts of G. b i l a a u s n. sp. appear much broader ( Fig. 3 View FIGURE 3 G) than those of G. lokaaus n. sp. ( Fig. 1 View FIGURE 1 F).

Four Gordionus View in CoL species have been described from the contiguous United States: G. l i n e a t u s ( Leidy, 1851) from the eastern United States, G. longiareolatus ( Montgomery, 1898) from California, G. platycephalus ( Montgomery, 1898) View in CoL from southern Montana (and also from Guatamala), and G. violaceus ( Baird, 1853) View in CoL from throughout the United States (and also found in Europe). In addition, Gordionus longistriatus Schmidt-Rhaesa, 2004 View in CoL has been described from Hawaii ( Schmidt-Rhaesa 2004) and Gordionus alascensis ( Montgomery, 1907) View in CoL has been described from Alaska.

The new forms described here are distinguished from all other Gordionus View in CoL species by their unique combinations of cuticle and circumcloacal spine structures. The cuticle of G. l o k a a u s n. sp. resembles that of G. lineatus View in CoL . However, in G. lineatus View in CoL the circumcloacal spines are thin and long ( Schmidt-Rhaesa et al. 2003; Smith 1991). The broad and tube-like circumcloacal spines of G. lokaaus n. sp. are unique within this genus and thus, distinguish this new species from G. lineatus View in CoL . The cuticle of G. bilaus n. sp. resembles most closely that of G. violaceus View in CoL , which has recently been shown to vary considerably throughout its European range ( Schmidt-Rhaesa 2001b). However, the circumcloacal spines of G. violaceus View in CoL are thin and long ( Schmidt-Rhaesa 2001b) and resemble those of G. lineatus View in CoL from the eastern United States ( Schmidt-Rhaesa et al. 2003). The broad circumcloacal spines set G. bilaus n. sp. apart from all other previously described Gordionus View in CoL species.

Laboratory rearing: Of almost 10 worm pairs of both species maintained in the laboratory for breeding purposes, mating was not observed and worm pairs never produced eggs. In addition, exhaustive searches in the field failed to find egg strings. Thus, measurements of eggs, larvae, and cysts could not be included in this manuscript.

Molecular analyses: Of the 88 worms sequenced, 30 unique nucleotide sequences were recovered. The phylogenetic tree based on the cox 1 barcoding region shows that the 2 new species produce 2 well-supported, monophyletic groups ( Fig. 5 View FIGURE 5 ). Sequences have been deposited in GenBank ( JX244228 View Materials – JX244257 View Materials ).