Bolbonema papillae, Larrazábal-Filho & Neres & Esteves, 2018

Larrazábal-Filho, Alexandre L., Neres, Patrícia F. & Esteves, André M., 2018, The genus Bolbonema Cobb, 1920 (Nematoda: Desmodoridae): emended diagnosis, key to males, and description of three new species from the continental shelf off northeastern Brazil, Zootaxa 4420 (4), pp. 551-570 : 558

Bolbonema papillae sp. n.

(measurements in Table 2, Figures 5 , 6 and 7 ).

Type material: Holotype Male adult MNRJ 392 . Station ME 2A1 (05°02'24.2''S, 36°23'11.9''W).

Paratype female: Adult, MNRJ 393. Station ME1C2 (05°01'11''S, 36°23'45''W).

Etymology. The specific epithet is given for the presence of papilliform supplements.

Description. HolotYpe ( Figures 5 and 6 ). BodY cYlindrical, Yellowish brown. Cuticle annulated eXcept in final portion of tail, no lateral differentiation. Eight longitudinal rows of somatic setae; two subdorsal, two subventral and four sublateral. TheY start from cervical region to level of cloaca, alternating in long setae with shorter setae. Head capsule well developed with thick cuticle without annulations. Anterior sensilla arrangement: siX outer labial papillae (difficult to see) and four cephalic setae positioned at anterior edge of fovea amphidialis. Fovea amphidialis multispiral with three turns. Fovea amphidialis large, posterior border eXceed the limit of the cephalic capsule entering the striations of the cuticle. Fovea occupYing 78% of diameter of head ( Fig 5C ). Buccal cavitY small, with one dorsal tooth and one small ventral tooth, not alwaYs visible. PharYnX muscular with well-developed posterior bulb. Cardia and eXcretorY-secretorY sYstem not observed. Nerve ring located 48 µm from anterior region. Reproductive sYstem monorchic, with single anterior testis situated to right of intestine, outstretched. ManY globular sperm cells. Spicules arched, proXimal region appearing folded. Gubernaculum laminar, well developed and surrounding distal portion of spicules ( Fig 5E ). Velum absent. Two precloacal supplements present, consisting of thin, rounded cuticular eXtensions. ( Fig 5D ) in subventral position. Tail conical with three small caudal glands and spinneret.

ParatYpe female ( Figures 6 and 7 ). Similar to male in bodY siZe, with minor differences: in female, cephalic setae positioned at middle level of fovea ( Fig 7B ), fovea amphidialis multispiral with 2.5 turns and smaller than male (i.e. seXuallY dimorphic), and tail conical-cYlindrical ( Fig 7D ). Female didelphic, ovaries antidromouslY refleXed and both genital branches to right of intestine. Vulva as simple transverse slit-like aperture. ProXimal portion of vagina slightlY cuticularised ( Fig 6D ). Globular sperm cells visible. No egg found. Vulva located at 52% of total bodY length (630 µm distant from anterior end). Tail conical.

Juveniles. No juvenile was found.

Diagnosis. Bolbonema papillae sp. n. is characteriZed bY the multispiral fovea amphidialis with three turns in the male and 2.5 in the female (seXual dimorphism) and two precloacal supplements present, consisting of thin, rounded cuticular eXtensions.

Differential diagnosis. Bolbonema papillae sp. n. is similar to Bolbonema longisetosum ( Jensen, 1985) in the presence of supplements. It differs in the shape of the fovea amphidialis (multispiral in B. papillae sp. n. and crYptospiral in B. longisetosum ) and the number and shape of supplements (two in B. papillae sp. n. and 24 papillae with associated setae in B. longisetosum ).

Bolbonema papillae sp. n. can be distinguished from Bolbonema spiralis Hourston & Warwick, 2010 and Bolbonema brevicolle Cobb, 1920 bY the shape of the fovea amphidialis; it is the onlY species in the genus that has a multispiral fovea with three turns. Moreover, B. papillae sp. n. has supplements, whereas B. spiralis and B. brevicolle do not.

Both Bolbonema papillae sp. n. and B. braziliensis sp. n. have two precloacal supplements, but theY differ in shape. B. papillae sp. n. has two precloacal supplements present, consisting of thin, rounded cuticular eXtensions, while B. braziliensis sp. n. has small papilliform supplements with setae. Other differences between these species are the shape of the fovea (crYptospiral in B. brasiliensis sp. n.) and the gubernaculum (gubernaculum a bent rod dorsallY oriented in B. braziliensis sp. n. and laminar with the distal portion surrounding the spicules in B. papillae sp. n.).

Figures

FIGURE 5. Bolbonema papillae sp. n. HOLOtypE MNRJ 392—A And C: AntERIOR REgIOn; B: OVERVIEW; D: tAIL REgIOn; And E: cOpULAtORy AppARAtUs.

FIGURE 6. Bolbonema papillae sp. n. A–B: cEphALIc And tAIL REgIOn Of pARAtypE fEMALE MNRJ 393. D: VULVA OpEnIng; C, E And F: hOLOtypE MALE MNRJ 392. C: cEphALIc REgIOn; E: gLObULAR spERM cELLs; And F: spIcULEs And pApILLAE.

FIGURE 7. Bolbonema papillae sp. n. PARAtypE fEMALE MNRJ 393—A: OVERVIEW; B And C: AntERIOR REgIOn; D: tAIL REgIOn; E: OVARy And VULVA OpEnIng.