Bolbonema zildae, 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 : 558-566

Bolbonema zildae sp. n.

(measurements in Table 3, Figures 8 , 9 and 10 ).

Type material: Holotype Male adult MNRJ 394 . Station CM 6 (05°01'21.2''S, 36°12'18.7''W).

Paratype female: Adult, MNRJ 395. Station ME1A1 (05°01'17.9''S, 36°23'31.8''W).

Other paratypes: 9 females (232 and 236 LMZOO-UFPE), 8 males (237–241 LMZOO-UFPE) and 4 J1, 3 J2 and 3 J3 (242 LMZOO-UFPE), data as for holotYpe .

Etymology. The species name is a tribute to Zilda Lacerda, the first author’s grandmother.

Description. HolotYpe ( Figures 8 and 9 ). 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 middle level of fovea amphidialis. Fovea amphidialis spiral with 1.25 turns. Fovea amphidialis occupYing 46% of diameter of head ( Fig 8B ). 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 58.5 µm from anterior region. Reproductive sYstem monorchic, with single anterior testis situated to left of intestine, outstretched. Sperm cells large ( Fig 8A ). Spicules arched, proXimal region bean-shaped. Velum present. Gubernaculum with dorsal apophYsis and distal portion enfolding spicules ( Fig 8E ). Velum present. Supplements absent. Tail conical, with three small caudal glands and spinneret.

ParatYpe female ( Figures 9 and 10 ). Similar to male. Female didelphic, ovaries antidromouslY refleXed and both genital branches to right of intestine. Vulva as simple transverse slit-like aperture. ProXimal portion of vagina heavilY cuticularised, proXimal portion of vagina surrounded bY constrictor muscle ( Fig 9E ). Globular sperm cells visible. Two eggs found. Vulva located at 43% of total bodY length (520 µm distant from anterior end). Tail conical.

Juveniles ( Figure 10 ). Similar to adults, eXcept lacking some characteristics such as supplements; reproductive sYstem immature. Juveniles in stage 1 without rows of somatic setae. Ten juveniles were found, four in stage 1, three in stage 2 and three in stage 3.

Diagnosis. Bolbonema zildae sp. n. is characteriZed bY the fovea amphidialis spiral with 1.25 turns. Spicules arched, proXimal region bean-shaped. Velum present. Gubernaculum well developed, hook-shaped, enfolding distal region of spicules.

Differential diagnosis. Bolbonema zildae sp. n. can be compared onlY with the species Bolbonema spiralis Hourston & Warwick, 2010 , in the shape of the fovea amphidialis and the absence of supplements. It differs in the shape of the spicules: B. zildae sp. n. has arched spicules with the proXimal region bean-shaped, the velum present, and the gubernaculum with a dorsal apophYsis; while B. spiralis has the proXimal region of the spicules simple, without cephalation, and a laminar gubernaculum.

Bolbonema zildae sp. n. differs from B. papillae sp. n. and B. braziliensis sp. n. in the absence of supplements and the spiral fovea with 1.25 turns. Two other species that differ are B. brevicolle Cobb, 1920 and B. longisetosum ( Jensen, 1985) , both of which have a crYptospiral fovea amphidialis. Moreover, B. longisetosum has 24 supplements (absent in B. zildae sp. n.). B. brevicolle has verY different spicules, the proXimal region without cephalation, and a laminar gubernaculum.

Figures

FIGURE 8. Bolbonema zildae sp. n. HOLOtypE MNRJ 394—A: OVERVIEW; B And C: AntERIOR REgIOn; D. tAIL REgIOn; And E: cOpULAtORy AppARAtUs.

FIGURE 9. Bolbonema zildae sp. n. A; B And E: PARAtypE fEMALE MNRJ 395; A: cEphALIc REgIOn; B: tAIL REgIOn; C–D: hOLOtypE MALE MNRJ 394; C: spIcULEs; D: cEphALIc REgIOn And E: OVARy And VULVA OpEnIng.

FIGURE 10. Bolbonema zildae sp. n. PARAtypE fEMALE MNRJ 395—A: OVERVIEW; B And C: AntERIOR REgIOn; D: tAIL REgIOn; E: AntERIOR REgIOn Of jUVEnILE 3; F: OVARy And VULVA OpEnIng.