Capitellus caramborum, García-Ruiz & Abolafia & Peña-Santiago, 2025

Capitellus caramborum sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4

Material examined.

Fourteen females and six males from two locations, in variable states of preservation.

Morphometrics.

See Table 1 View Table 1 .

Description.

Baena (type) population:

Adult. Slender (a = 40–49) nematodes of small to medium size, 0.82–1.04 mm long. Body cylindrical, tapering towards both extremities. Upon fixation, habitus regularly curved ventrad, often adopting an open C shape. Cuticle dorylaimid, two-layered, thin, ca 1 µm thick throughout the entire body, outer layer bearing very fine transverse striation, better observable with SEM. Lateral chord 6.0–6.5 µm wide, occupying less than one-third (26–31 %) of mid-body diameter, bearing abundant granular gland bodies. Body pores abundant, appearing as (SEM observations, Fig. 4 J View Figure 4 ) short longitudinal slits. Lip region cap-like, offset by constriction, 1.7–2.0 times as wide as high and up to one-third (28–33 %) of body diameter at neck base, with a well-differentiated, refractive perioral disc; SEM observations: lips amalgamated, their inner region visibly offset and somewhat expanded, forming a small sucker-like perioral disc 4.0–4.5 µm wide and divided into six triangular sectors by the existence of six radial, interlabial incisures running from the oral aperture to the margin of the disc, labial and cephalic papillae low, but comparatively large and distinct, button-like, with a coarse pore at their center. Amphid fovea cup-like, its opening 6.0–6.5 µm wide, occupying the entire diameter of lip region. Cheilostom 6.0–6.5 µm long, almost cylindrical, thin-walled, with circumoral sclerotized pieces at its anterior end. Odontostyle typical dorylaimid but small, almost equal (0.9–1.0 times) to lip region diameter long, occupying 0.56–0.66 % of body length, ca 5.0 times as long as wide, with short aperture ca one-fifth of its length. Guiding ring simple, often inconspicuous. Odontophore visibly flanged, 1.8–2.0 times the odontostyle. Pharynx consisting of a slender and weakly muscular anterior region suddenly enlarging into the basal expansion 10–16 times as long as wide, 5.3–8.1 times longer than body diameter at neck base, occupying more than half (53–59 %) of the total neck length, and surrounded by a distinct spiral muscular sheath, its gland nuclei and outlets obscure in the specimens examined, some specimens bearing a few refractive globules at its anterior end. Cardia small and rounded, 9–11 µm long.

Female. Genital system diovarian, with both branches equally and variably developed, the anterior 74–122 µm or 8–12 % of the total body length, the posterior 87–108 µm or 9–11 %. Ovaries comparatively small, often not reaching the oviduct-uterus junction, 31–61 µm the anterior and 36–48 µm the posterior, with oocytes first arranged in two or more rows and then in one single one. Oviduct 42–65 µm or 2.1–3.3 body diameters long, consisting of a long and slender distal region made of prismatic cells and a developed proximal pars dilatata with visible lumen. A distinct sphincter present between oviduct and uterus. Uterus a simple tube-like structure 27–38 µm or 1.4–1.9 body diameters long. Vagina extending inwards 8.0–9.5 µm, to less than one-half (38–45 %) of body diameter: pars proximalis 5.0–6.0 × 6.0–6.5, with almost straight to somewhat convergent walls that are encircled by weak musculature, pars distalis 3.0 µm long. Vulva a longitudinal slit ca 2 µm long. Prerectum 6.2–6.6, rectum 1.2–1.3 anal body diameters long. Tail convex conoid to slightly subcylindrical.

Male. Genital system diorchic, with opposite testes. In addition to the adcloacal pair, situated at 4–5 µm from the cloacal aperture, there invariably are four very simple (non-mammiform but a low pore-like structure, Fig. 4 I View Figure 4 ) ventromedian supplements arranged in a more posterior pair located at 38–41 µm from the ad-cloacal pair and two more anterior and spaced ones at 23–25 µm from the posterior pair. Spicules dorylaimid, strongly curved ventrad, 3.7–4.1 times as long as wide and 1.4–1.7 times longer than body diameter: head 3.0–3.5 µm long, up to one-sixth (13–15 %) of spicule length, and almost as long as wide; median piece occupying less than one-third (15–31 %) of maximum width; ventral hump and hollow very prominent, the former located at 7.5–9.0 µm from the anterior end; curvature 127–128 °. Lateral guiding piece simple, 6 µm long. Tail somewhat less convex conoid than that of female.

Antequera population.

Females are morphologically identical and morphometrically very similar to those of the type population, as the ranges of their more relevant measurements and ratios are coincident or widely overlap. No male found.

Molecular characterization.

After sequencing and editing, four sequences were obtained for phylogenetic analyses. Two 18 S rDNA sequences, 1719 bp in length (acc. PQ 877190 – PQ 877191), showed 98.14 % identity to a sequence ( AY 552969 View Materials ) assigned to Dorylaimellus virginianus Cobb, 1913 ( Jairajpuri & Ahmad, 1980) and 97.85 %, 97.62 %, and 98.02 % identity to sequences assigned to D. montenegricus Andrássy, 1959 ( Jairajpuri & Ahmad, 1980), D. parvulus Thorne, 1939 ( Jairajpuri & Ahmad, 1980), and D. tenuidens Thorne, 1939 , respectively ( AY 284821 View Materials , AY 911968 View Materials , and AY 911972 View Materials ).

Two 28 S rDNA sequences, 793 bp in length (acc. PQ 877192 – PQ 877193), showed 83.61 % identity to two sequences ( KT 258984 View Materials , KT 25985) assigned to Belondira bagongshanensis Wu, Huang, Xie, Wang & Xu, 2017 , 91.14 % to those of Belondira sp. ( MG 921267 View Materials , MG 921268 View Materials ), and 80.71 % identity to B. coomansi Golhasan, Heydari, Miraeiz, Abolafia & Peña-Santiago, 2018 ( MF 363124 View Materials ).

Diagnosis.

The new species is characterized by its 0.82–1.09 mm long body, lip region offset by constriction, and 6.0–6.5 µm wide with a distinct perioral refractive disc 4.0–4.5 µm wide, odontostyle 6.0–6.5 µm long, odontophore bearing basal flanges and 1.8–2.0 times the odontostyle long, neck 223–296 µm long, pharyngeal expansion occupying 53–59 % of the total neck length, female genital system diovarian, uterus simple and 27–38 µm or 1.4–1.9 body diameters long, vulva (V = 53–56) longitudinal, tail convex conoid to subcylindrical (24–34 µm, c = 31–38, c ’ = 1.8–2.1), spicules strongly curved ventrad and 23–25 µm long, and four ventromedian supplements.

Separation from its relatives.

The new species is similar to C. capitatus and D. neocapitatus . It differs from C. capitatus , a mainly pantropical taxon, in its longer (0.82–1.09 vs. 0.58–0.65 mm) and slender (a = 44–51 vs. a = 30–37 in females) body, lip region offset by constriction (vs. almost continuous), larger odontostyle (5.5–6.5 vs. 4.5 µm), comparatively shorter tail (c = 31–38 vs. c = 21–25), and male present (vs. absent). From D. neocapitatus , a very close taxon, in its narrower lip region (6.0–6.5 vs. 6.5–7.5 µm wide, n = 21), longer odontostyle (6.0–6.5 vs. 5.0–5.5 µm) – it means that the odontostyle is almost equal vs. appreciably shorter than lip region diameter –, relatively shorter pharyngeal expansion (53–59 vs. 59–63 % of the total neck length), more conoid (vs. more subcylindrical, Fig. 3 F – H View Figure 3 ), and comparatively longer female tail (c ’ = 1.8–2.1 vs. c ’ = 1.3–1.7), and male present (vs. absent).

Type locality and habitat.

Southern peninsular Spain, the Andalusia region, Córdoba province, Baena municipality, “El Valle” farm (37.799704, - 4.310439, elevation 351 m), where the new species was found in the rhizosphere of an olive grove GoogleMaps .

Other locality and habitat.

Southern peninsular Spain, the Andalusia region, Málaga province, Antequera municipality, “La Capilla” farm (37.198283, - 4.543868, elevation 491 m), where the new species was found in the rhizosphere of an olive grove GoogleMaps .

Etymology.

The specific name refers to the “ Carambos, ” the familiar nickname of the first author’s mother.