Oxyascaris caatingae, Felix-Nascimento & Vieira & Muniz-Pereira & Moura & Ribeiro & Oliveira, 2020

Felix-Nascimento, Gabriela, Vieira, Fabiano Matos, Muniz-Pereira, Luís Cláudio, Moura, Geraldo Jorge Barbosa De, Ribeiro, Leonardo Barros & Oliveira, Jaqueline Bianque De, 2020, Two new species of Cosmocercidae (Nematoda: Cosmocercoidea) of Leptodactylus macrosternum Miranda-Ribeiro (Anura: Leptodactylidae) from Caatinga Biome Brazil, Zootaxa 4877 (2), pp. 274-290 : 281

Oxyascaris caatingae n. sp.

( Figs. 4 and 5 )

General. Sexual dimorphism evident, with females up to four times larger than males. Males with numerous somatic papillae ( Fig. 5C ), females without somatic papillae. Lateral body alae absent in both sexes. Cephalic end with three lips and triangular buccal aperture ( Fig. 4C , 5A, B ). Dorsal lip with two large papillae on the edge ( Fig. 4C , 5A, B ). Lateroventral lips with two papillae on the edge, one large on the ventral edge, and another small on dorsal edge of each lip ( Fig. 4C , 5A, B ). Lateral amphids ( Fig. 4C , 5A, B ). Oesophagus oxyuriform, divided into four parts: pharynx, corpus, isthmus and bulb ( Fig. 4 A–B). Nerve ring anterior to excretory pore, located between the anterior third and middle third of the oesophagus ( Fig. 4 A-B). Excretory pore located at the level of oesophageal isthmus, between the middle third and the posterior third of the oesophagus ( Fig. 4 A–B).

Male (based on 4 specimens): Total body length 4.4–4.8 (4.6±0.2) mm, body width at level of oesophagusintestinal junction 150–175 (159±12). Total oesophagus length 396–575 (458±84); pharynx 34–38 (36±2) long, corpus 251–396 (337±76) long, isthmus 59–83 (75±13) long, bulb 50–62 (57±6) long. Nerve ring 197–211 (205±8) and excretory pore 385–451 (420±27) from anterior end. Caudal papillae slightly larger in size than somatic papillae. Caudal papillae slightly larger in size than somatic papillae (5+1:1:9) ( Fig. 4 D–E). Five pairs of lateroventral precloacal papillae ( Fig. 4 D–E, 5C), with the first located anterior to proximal end of spicules and the fifth pair immediately anterior to cloacal aperture ( Fig. 4 D–E). One large unpaired medial precloacal papilla on the anterior border of cloacal aperture ( Fig. 4 D–G, 5E, F). One pair of lateral adcloacal papillae located at the commissure of the cloacal aperture ( Fig. 4 D–G, 5E, F). Nine pairs of postcloacal papillae; the first lateroventral pair just below the adcloacal papillae; second pair lateroventral and posterior to the first pair; third pair lateroventral posterior to the second pair, but more external to the second pair; fourth pair lateral; fifth pair lateroventral; sixth pair lateral; seventh pair lateroventral; eighth pair lateral, slightly posterior than the seventh pair; and ninth pair laterodorsal, aligned transversely with the eighth pair ( Fig. 4 D–G, 5E–G). Small lateral phasmids, posterior to the eighth pair of postclocal papillae ( Fig. 4F , 5G ). Spicules equal and slender, with rounded proximal end and slightly rounded distal end, not alate, 95–109 (103±7) long ( Fig. 4 D–G, I). Gubernaculum present, slender in ventral view, 30–50 (41±10) long ( Fig. 4 D–G, J). Tail conical ( Fig. 4 D–G, 5C, E, G), 205–265 (238±25) long.

Female (based on 8 specimens): Total body length 9.7–21.9 (13.8±4.5) mm, body width at level of oesophagus-intestinal junction 187–291 (225±39). Total oesophagus length 620–884 (759±99); pharynx 38–52 (43±5) long, corpus 507–761 (625±98) long, isthmus 60–96 (80±13) long, bulb 56–103 (73±15) long. Nerve ring 242–375 (292±52) and excretory pore 466–830 (613±114) from anterior end. Didelphic and amphidelphic, with the ovary of the anterior uterus located anterior to the vulvar opening and the ovary of the posterior uterus located posterior to the vulvar opening. Vulva preequatorial, not protruded, 4.1–9.6 (6.1±2.0) mm from anterior end. Ovijector thin and muscular along its entire length, anteriorly directed ( Fig. 4K ). Eggs oval, larvated in ovijector ( Fig. 4K ), 68–103 (85±11) long and 37–68 (54±8) width ( Fig. 4K ). Tail conical elongated, 810–1,539 (997±241) ( Fig. 4H , 5D ).

Figures

FIGURE 4. Oxyascaris caatingae n. sp. (A) anterior region, male, ventral view. (B) anterior region, male, lateral view. (C) anterior end, male, apical view. (D) posterior region, male, ventral view. (E) posterior region, male, lateral view. (F) tail, male, lateral view. (G) tail, male, ventral view; (H) tail of female, lateral view. (I) left spicule, ventral view. (J) gubernaculum, ventral view. (k) vulva, ovijector, and eggs, lateral view.

FIGURE 5. Oxyascaris caatingae n. sp. (A) anterior end, male, apical view (white arrows indicate the cephalic papillae). (B) anterior end, female, apical view (white arrows indicate the cephalic papillae). (C) posterior region, male, latero ventral view. (D) tail, female, latero venral view. (E) tail, male, latero ventral view. (F) cloacal region, male, latero ventral view. (G) tip of tail, male, latero ventral view. (*—somatic papillae; 1st–9th—first to ninth post cloacal papillae; a—amphid; ad—ad cloacal papillae; an—anus; dl—dorsal lip; lvl—latero ventral lip; pre—pre cloacal papillae; u—unpaired pre cloacal papillae).