Bolbonema brevicolle Cobb, 1920

Armenteros, Maickel, Ruiz-Abierno, Alexei & Decraemer, Wilfrida, 2014, Revision of Desmodorinae and Spiriniinae (Nematoda: Desmodoridae) with redescription of eight known species, European Journal of Taxonomy 96, pp. 1-32 : 8

Bolbonema brevicolle Cobb, 1920

Figs 1E–F , 3 , Table 1

Bolbonema brevicolle Cobb, 1920: 264 .

Desmodora (Bolbonema) brevicolle – Gerlach 1963: 90.

Material examined

6 ♂♂, 7 ♀♀ and 1 juvenile, deposited in the nematode collection at Centro de Investigaciones Marinas, Universidad de La Habana, CUBA.

Description

Cuticle annulated in the anterior region (annuli 0.6–0.8 μm width) becoming finely striated at midbody (0.2–0.3 µm). Head capsule well developed, surface appearing with a fingerprint pattern by LM, SEM microphotographs suggest some depressions in the surface. Six inner and six outer labial sensilla papilliform. Four cephalic sensilla (10–13 μm long) at the base of the head capsule, four subcephalic setae (6–8 µm long) next to the cephalic ones. Amphidial fovea cryptospiral, relatively large, posterior border is in contact with cuticle striations. Eight longitudinal rows of somatic setae running from cervical region to level of anus; long setae (18–22 μm long) alternate with two shorter setae (~ 4 μm long). Buccal cavity small, with one small dorsal tooth and two ventrosublateral denticles, not always visible. Pharynx muscular with well-developed posterior bulb and plasmatic interruptions. Cardia and excretory-secretory system not observable. Tail region with only four longitudinal rows of setae.

Male monorchic; anterior testis to the right of the intestine. Spicule capitulum with a characteristic ventral process. No precloacal supplements.

Female didelphic, ovaries antidromously reflexed and both genital branches to the right of the intestine. Vulva a simple transversal slit-like aperture.

Juveniles are similar to adults except for the development of the reproductive system.

Remarks

Our specimens largely agree with the original description of this species by Cobb (1920) and redescriptions by Gerlach (1963) and Pastor de Ward (1988). The single clear difference in our specimens is the presence of four subcephalic setae in subdorsal and subventral positions slightly smaller than the four cephalic sensilla and inserted closely to the latter ( Fig. 3B ). These setae were clearly visible with SEM and could have been overlooked by mentioned authors in LM; actually, we could not see them clearly in all specimens. The body length shows some variation for the different populations with a considerably smaller female (737 μm) described by Gerlach (1963), and larger specimens described by Pastor de Ward (1988) (range: 1550–1950 µm). The range of body length of our specimens is more in agreement with the type specimens (males: 1051–1372 µm, females: 942– 1387 µm) and it is closer to the holotype described by Cobb (1920) (female: ~ 1300 µm). The cuticle heterogeneity in annulation is quite marked in B. brevicolle with the anterior annuli being rings three-fold wider than the striation in the posterior region; however, this feature has not been mentioned in previous descriptions.

Figures

Fig. 1. A–D. Acanthopharynx denticulatus Wieser, 1954, ♂. A. Head region. B. Tail region. C. Copulatory apparatus. D. Neck region. E–F. Bolbonema brevicolle Cobb, 1920, ♂. E. Neck region. F. Posterior region with tail end in surface view.

Fig. 3. Bolbonema brevicolle Cobb, 1920, SEM microphotographs of ♂ (A) and ♀ (B, C & D). A. Head in oblique en face view. B. Head in oblique lateral view. C. Cuticle striation at anterior region. D. Cuticle striation at mid-body region.