The genus
Here, we describe five new
In addition to collecting millipedes in different parts of Japan, a field trip to Hongkong was conducted in June 2017. Basically all major areas in Hongkong, including the new territories have been visited and more than 250 specimens of scarabaeoid beetles belonging to 16 species in 13 genera were collected. Nematodes were isolated using standard procedures as previously described (Herrmann et al., 2006). In total, we isolated and characterized 12 strains of the Diplogastridae family with eight of these strains representing members of the genus
Light microscopic observations for drawings and morphometrics were conducted using live nematode material, which was handpicked from culture plates as described previously (Kanzaki, 2013).
Remarks concerning morphometric measurements: based on our repeated findings that measurements of certain nematode dimensions can change over time as a result to different culture conditions (Fonderie et al., 2013; Kanzaki et al., 2012a,2013; Ragsdale et al., 2015; Herrmann et al., 2016), we combine molecular, morphological, biological, and ecological information to characterize new material as broadly as possible.
To examine reproductive isolation of the new species we crossed them with the most closely related species in the phylogeny. In the case of the four new species
A species phylogeny of the complete
We carried out field trips to Taiwan, Japan, and Hongkong in 2016 and 2017 as described in detail in “materials and methods” and in the accompanying publication (Yoshida et al., 2018). In Japan and Hongkong, we isolated a total of 12 gonochoristic
We performed mating experiments to confirm reproductive isolation between
Most
The adult body can be described as follows: Body cylindrical, stout; cuticle thick, with fine annulation and clear longitudinal striations; lateral field consisting of two lines, only weakly distinguishable from body striation with the presence of deirid; head without apparent lips, and with six short and papilliform labial sensillae; four small, papilliform cephalic papillae present in males, as typical for diplogastrid nematodes; amphidial apertures located on the lateral sector, slightly dorsally shifted, at level of margin of cheilo- and gymnostom; stomatal dimorphism present, with stenostomatous (narrow mouthed) and eurystomatous (wide mouthed) forms occurring in males and females, the latter (i.e. eurystomatous form), however, less frequent in males. Detailed stomatal morphology is described below. Dorsal pharyngeal gland clearly observed, penetrating dorsal tooth to gland opening; anterior part of pharynx (= pro and metacorpus) 1.5 times as long as posterior part (= isthmus and basal bulb); procorpus very muscular, stout, occupying half to two-thirds of corresponding body diameter; metacorpus very muscular, forming well-developed median bulb; isthmus narrow, not muscular; basal bulb glandular; pharyngo-intestinal junction clearly observed, well developed; nerve ring usually surrounding middle region of isthmus; excretory pore not conspicuous, ventrally located at level of isthmus to pharyngo-intestinal junction, excretory duct extending anteriad and reflexed back to position of pore; deirid observed laterally, located from slightly anterior to pharyngo-intestinal junction to a half body diameter posterior to the junction; hemizonid not clearly observed; lateral glands, small pores connected to secretory cell, present and observed on the lateral body surface, with positions inconsistent among individuals, numbering 5 to 8 for males and 9 to 13 for females.
Cheilostom consisting of six per- and interradial plates. Incision between plates is not easily distinguished by light microscopy. Anterior end of each plate rounded and elongated to project from stomatal opening and form a small flap; gymnostom short, cuticular ring-like anterior end overlapping cheilostom internally; dorsal gymnostomatal wall slightly thickened compared to ventral side; stegostom separated into three subsections: pro-meso, meta, and telostegostom; pro-meso stegostom forming a weakly cuticularized ring surrounding the anterior edge of pharynx. Metastegostom bearing conspicuous and movable triangular or flint-shaped dorsal tooth with strongly sclerotized surface giving an appearance of an inverted V-shape in light microscopy in lateral view; pointed left subventral ridge with three minute adventitious denticles on a plate; pointed right subventral ridge, often with distinct distal adventitious denticle(s). Telostegostom forming a weakly sclerotized cup-like cavity connecting stoma and pharynx.
Cheilostom divided into six distinctive per- and interradial plates. Anterior end of each plate rounded and elongated to project from stomatal opening, forming a small flap; gymnostom with thick cuticle, forming a short, ring-like tube being thicker posteriorly; anterior end of gymnostom internally overlapping posterior end of cheilostomatal plates; stegostom separated into three subsections: pro-meso, meta, and telostegostom; pro-mesostegostom forming a weakly cuticularized ring surrounding the anterior edge of pharynx; metastegostom bearing large claw-like dorsal tooth; right subventral tooth; ridge of left subventral denticles or cusps, varying in number and size; dorsal and right subventral teeth movable; no movement observed for left subventral denticles; telostegostom forming a weakly sclerotized cup-like cavity connecting stoma and pharynx.
The male body can be described as follows: Ventrally arcuate, strongly ventrally curved at tail region when killed by heat. Testis single, ventrally located, anterior part reflexed to right side; spermatogonia arranged in three to five rows in reflexed part, then well-developed spermatocytes arranged as three to four rows in anterior two-thirds of the main branch, then mature amoeboid spermatids arranged in multiple rows in remaining, proximal part of gonad; vas deferens not clearly separated from other parts of gonad; three (two subventral and one dorsal) cloacal gland cells observed at distal end of testis and intestine; spicules paired, separate; spicules smoothly curved in ventral view, adjacent to each other for distal third of their length, each smoothly tapering to pointed distal end; spicule in lateral view smoothly ventrally arcuate, giving spicule about 100° curvature, oval manubrium present at anterior end, lamina/calomus complex (blade) clearly expanded slightly posterior to manubrium (
The female body can be described as follows: Relaxed or slightly ventrally arcuate when killed by heat. Gonad didelphic, amphidelphic; each gonadal system arranged from vulva/vagina as uterus, oviduct, and ovary; anterior gonad right of intestine, with uterus and oviduct extending ventrally and anteriorly on right of intestine and with a totally reflexed (= antidromous reflexion) ovary extending dorsally on left of intestine; oocytes mostly arranged in three to four rows in distal two-thirds of ovary and in double or single row in rest of ovary, distal tips of each ovary reaching oviduct of opposite gonad branch; anterior end of oviduct (= junction tissue between ovary and oviduct) consists of rounded cells; anterior part of oviduct consists of rounded cells, forming a simple tube; middle part of oviduct serving as spermatheca, consists of roundish and relatively large cells. Eggs in single to multiple-cell stage or even further developed at posterior part of oviduct (= uterus), in young females being composed of squared or angular cells, long enough to contain one well developed oocyte.
Diagnostic characters, i.e., stomatal morphology and male tail characters (arrangement of genital papillae) are herein described for each species including measurements for all species (Tables 1–3). Additionally, these typological characters applicable to species diagnosis of the
Morphometrics of P. laevicollis sp. n.
Character |
|
Stenostomatous female |
---|---|---|
n | 10 | 10 |
L | 834 ± 104 (662–971) | 1104 ± 209 (746–1325) |
L’ | 705 ± 89.6 (566–836) | 908 ± 179 (595–1126) |
a | 15 ± 1 (13–17) | 13 ± 0.8 (12–15) |
b | 6.5 ± 0.5 (5.9–7.4) | 7.6 ± 0.8 (5.8–8.6) |
c | 6.5 ± 0.4 (5.9–7.2) | 5.7 ± 0.7 (4.6–6.9) |
c’ | 3.9 ± 0.4 (3–4.3) | 5.8 ± 0.7 (4.9–7.1) |
T or V | 59 ± 2 (56–62) | 46 ± 2.1 (42–49) |
Maximum body diam. | 57 ± 7.4 (47–66) | 83 ± 14.8 (57–97) |
Stoma length | 9.4 ± 1 (7.7–10.6) | 11.1 ± 1.1 (9–12.5) |
Stoma diam. | 5.6 ± 0.7 (4–6.4) | 6.4 ± 0.7 (5.5–8.0) |
Pharynx length (head to base of pharynx) | 118 ± 9.5 (103–132) | 137 ± 15.5 (113–154) |
Anterior pharynx (pro– + metacorpus) | 72 ± 6.7 (61–81) | 84 ± 8.7 (71–93) |
Posterior pharynx (isthmus + basal bulb) | 46 ± 2.9 (42–51) | 53 ± 7.1 (42–63) |
Ant/total pharynx % | 61 ± 1 (58–61) | 61 ± 1.2 (59–63) |
Median bulb diam. | 20 ± 2.1 (16–22) | 27 ± 3.1 (22–30) |
Terminal bulb diam. | 19 ± 1.7 (16–21) | 25 ± 3.8 (19–31) |
Testis length | 490 ± 72.5 (370–570) | – |
Ant. end to vulva | – | 504±86.2 (365–613) |
Vulva to anus distance | – | 410 ± 78.9 (275–523) |
Cloacal or anal body diam. | 33 ± 2.3 (28–36) | 34 ± 4.5 (32–60) |
Tail length | 129 ± 17.4 (96–152) | 196 ± 47.1 (138–285) |
Spicule length (curve) | 44 ± 2.5 (40–47) | – |
Spicule length (chord) | 35 ± 2.1 (31–38) | – |
Gubernaculum length | 16 ± 1 (14–17) | – |
Morphometrics of P. honkongensis sp. n. and P. neolucani sp. n.
Character |
|
Stenostomatous female |
|
Stenostomatous female |
---|---|---|---|---|
n | 10 | 10 | 10 | 10 |
L | 1014 ± 185 (700–1302) | 1181 ± 315 (918–2008) | 871 ± 49.6 (775–951) | 1060 ± 111.1 (930–1297) |
L’ | 847 ± 184 (560–1125) | 940 ± 288 (703–1700) | 745 ± 50.7 (658–826) | 864 ± 103.2 (743–1080) |
a | 14 ± 3.7 (11–24) | 13 ± 0.9 (12–15) | 15 ± 1 (14–16) | 14 ± 0.7 (13–15) |
b | 6 ± 1 (4.6–7.7) | 6.6 ± 1.1 (5.6–9.5) | 5.4 ± 0.6 (4.7–6.6) | 5.5 ± 0.4 (4.8–6.5) |
c | 6.1 ± 1.3 (5–8.5) | 4.8 ± 0.7 (4.3–6.5) | 7 ± 0.9 (6.1–9.2) | 5.4 ± 0.5 (4.5–6.1) |
c’ | 4.2 ± 0.9 (3–5.9) | 6.3 ± 0.5 (5.1–6.9) | 3.7 ± 0.7 (2.6–4.9) | 6.1 ± 0.9 (5–7.8) |
T or V | 53 ± 4.8 (51–68) | 45 ± 2.6 (42–50) | 53 ± 7.5 (33–59) | 47 ± 1.3 (45–48) |
Maximum body diam. | 73 ± 14.9 (51–96) | 92 ± 29.4 (67–170) | 57 ± 5.8 (49–67) | 75 ± 9 (63–95) |
Stoma length | 12.6 ± 1 (11.4–14.6) | 13.3 ± 1.6 (10.3–16) | 10.4 ± 1 (8.7–12) | 11 ± 0.9 (10.2–13) |
Stoma diam. | 7.2 ± 0.7 (6.1–8.5) | 7.7 ±1.1 (6.5–9.7) | 6.0 ± 0.7 (5.3–7.6) | 7.1 ± 0.7 (6.3–8.4) |
Pharynx length (head to base of pharynx) | 155 ± 9.7 (140–172) | 168 ± 14 (154-202) | 151 ± 11.9 (129-169) | 182 ± 14.9 (149-194) |
Anterior pharynx (pro- + metacorpus) | 98 ± 5.4 (90–106) | 106 ± 7.4 (94–117) | 95 ± 10.2 (76–112) | 116 ± 9.2 (97–128) |
Posterior pharynx (isthmus + basal bulb) | 57 ± 5.9 (49–66) | 62 ± 8.4 (56–85) | 56 ± 5.3 (51–69) | 66 ± 7.1 (52–75) |
Ant/total pharynx % | 63 ± 2 (60–66) | 63 ± 2.5 (58–66) | 63 ± 3.2 (59–67) | 64 ± 1.8 (61– 66) |
Median bulb diam. | 27 ± 2 (24–31) | 31 ± 3.6 (26–38) | 25 ± 1 (24–27) | 31 ± 2.9 (27–36) |
Terminal bulb diam. | 26 ± 2.2 (22–28) | 29 ± 6.6 (24–47) | 25 ± 1.3 (22–27) | 29 ± 1.7 (27–33) |
Testis length | 540 ± 141 (366–765) | – | 467±43 (425–561) | – |
Ant. end to vulva | – | 539 ± 172 (384–995) | – | 493 ± 50.9 (420–581) |
Vulva to anus distance | – | 419 ± 149 (320–815) | – | 371 ± 47 (290–447) |
Cloacal or anal body diam. | 41 ± 5.4 (30–50) | 39 ± 8 (32–60) | 35 ± 4.8 (27–43) | 32 ± 3.8 (27–38) |
Tail length | 167 ± 21.6 (140–206) | 241 ± 30 (215–308) | 125 ± 13.2 (99–148) | 196 ± 19 (175–228) |
Spicule length (curve) | 53 ± 4.2 (44–57) | – | 47±2.3 (43–51) | – |
Spicule length (chord) | 45 ± 3.7 (37–49) | – | 36 ± 1.7 (34–39) | – |
Gubernaculum length | 19 ± 1.8 (17–22) | – | 17 ± 1.5 (14–19) | – |
Morphometrics of P. riukiariae sp. n. and P. degawai sp. n.
Character |
|
Stenostomatous female |
|
Stenostomatous female |
---|---|---|---|---|
n | 10 | 10 | 10 | 10 |
L | 918 ± 162 (663–1180) | 1362 ± 211 (1025–1700) | 872 ± 142.2 (710–1105) | 1184 ± 310.5 (811–1853) |
L’ | 780 ± 151 (553–1010) | 1142 ± 201 (835–1466) | 727 ± 134.6 (585–961) | 986 ± 282 (652–1600) |
a | 12 ± 2.5 (9.4–15) | 14 ± 1.5 (11–16) | 16 ± 2 (13–19) | 16 ± 3 (132–23) |
b | 5.7 ± 0.8 (5–7.5) | 8.4 ± 1.5 (5.9–10.8) | 5.3 ± 0.6 (4.6–6.4) | 6.6 ± 1.2 (5.1–8.6) |
c | 6.8 ± 1.2 (5.4–9.3) | 6.2 ± 0.7 (5–7.3) | 6 ± 0.8 (5.4–7.7) | 6 ± 0.9 (4.7–7.3) |
c’ | 3.4 ± 0.4 (2.7–4.2) | 5.2 ± 0.6 (4.5–6.1) | 4.1 ± 0.5 (3.3–4.7) | 5.2 ± 1 (3.8–7.3) |
T or V | 51 ± 5.3 (41–59) | 45 ± 11.1 (32–72) | 45 ± 5 (40–56) | 51 ± 5.5 (45–63) |
Maximum body diam. | 78 ± 13.2 (62–97) | 99 ± 19.4 (65–128) | 56 ± 14.4 (40–80) | 80 ± 28.6 (37–138) |
Stoma length | 11.1 ± 1 (9.7–12.5) | 11.8 ± 1.3 (9.2–14) | 11.4 ± 0.8 (10–12.3) | 12.1 ± 0.9 (11–13.4) |
Stoma diam. | 6.5 ± 0.8 (5.4–7.6) | 7.3 ±0.7 (6.2–8.4) | 6.7 ± 0.3 (6.3–7) | 7.6 ± 0.6 (6.9–8.7) |
Pharynx length (head to base of pharynx) | 143 ± 17.6 (111–167) | 156 ± 12.2 (136–178) | 152 ± 10.1 (143–176) | 169 ± 16.3 (148–207) |
Anterior pharynx (pro– + metacorpus) | 94 ± 11 (78–111) | 97 ± 8.8 (86–116) | 95 ± 4.2 (89–103) | 106 ± 8.4 (96–122) |
Posterior pharynx (isthmus + basal bulb) | 54 ± 5.8 (43–63) | 58 ± 7 (40–66) | 58 ± 7.1 (47–73) | 62 ± 9.6 (51–85) |
Ant/total pharynx % | 67 ± 11.9 (59–100) | 62 ± 3.4 (60–71) | 62 ± 2.4 (59–67) | 64 ± 2.3 (60– 68) |
Median bulb diam. | 27 ± 2.2 (23–31) | 31 ± 1.4 (29–33) | 26 ± 3 (22–32) | 30 ± 4.6 (24–41) |
Terminal bulb diam. | 24 ± 2.8 (19–28) | 28 ± 2.3 (24–32) | 25 ± 4 (19–33) | 28 ± 4.8 (22–39) |
Testis length | 468 ± 116.4 (295–677) | – | 397 ± 105.7 (285–580) | – |
Ant. end to vulva | – | 624 ± 199 (415–1040) | – | 601 ± 173.3 (416–1043) |
Vulva to anus distance | – | 510 ± 94.6 (332–665) | – | 365 ± 72.8 (255–487) |
Cloacal or anal body diam. | 41 ± 4.5 (32–46) | 43 ± 6.1 (31–52) | 35 ± 5.6 (30–44) | 39 ± 8.7 (22–55) |
Tail length | 137 ± 21.2 (104–170) | 220 ± 14.3 (190–241) | 145 ± 14.5 (125–180) | 198 ± 36.8 (150–253) |
Spicule length (curve) | 53 ± 5.5 (40–60) | – | 47±7.6 (37–57) | – |
Spicule length (chord) | 43 ± 3.4 (36–47) | – | 40 ± 6.9 (32–50) | – |
Gubernaculum length | 12 ± 2.5 (9.4–15) | – | 16 ± 2.4 (13–19) | – |
Summary of diagnostic characters of the
Stenostomatous form | Eurystomatous form | ||||||
---|---|---|---|---|---|---|---|
Species | Reproductive mode | Right subventral plate | Left subventral plate | Right subventral tooth | Left subventral cusps | Genital papillae | Other characteristic feature(s) |
|
H | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like | three large cusps each sometimes split into two (= 3-6 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | single peak | three bumps | claw-like | Three large cusps each sometimes split into two to three (= 3-9 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like with or without blunt projection | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 2: v1-v2d > v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like with blunt projection | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 3: v1-v2 = v2-v4; v2 and v3d are separated | |
|
G | 1-2 peaks | with minute denticles | claw-like | three large cusps each sometimes split into two (= 3-6 peaks) | Type 3: v1-v2 = v2-v4; v2 and v3d are separated | |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 4: v1-v2 < v2-v4; v2 and v3d are separated | |
|
G | Two peaks | Three bumps | Two large ridges or multiple small denticles | Three large cusps each sometimes split into two to three (= 3-9 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | Type 1: v1-v2d = v2d-v4; v2d and v3 are close to each other | |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | v1-v2d = v2d-v4; v2d and v3 are close to each other | v2 and v3 are very close, and sometimes third pair is directed sublaterally (v3d) |
|
G | Single peak | Three bumps | Claw-like | Three large cusps each split into three or more (= more than 9 peaks) | v1-v2 < v2-v4; v2 and v3d are separated | Comparatively large and slightly more barrel-shaped stoma in eurystomatous form |
|
G | 1-2 peaks | Three bumps | Claw-like | Three large cusps each sometimes split into two (= 3-6 peaks) | v1-v2 < v2-v4; v2 and v3d are separated |
sp. n. (Figs 2–5; Tables 1, 4, and 5).
The table shows the number of molecular differences in the 1.6kb SSU rRNA sequence for every pairwise comparison in the
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
0 | 8 | 5 | 10 | 6 | 3 | 6 | 21 | 16 | 35 | 25 | 31 | 42 | 36 |
|
– | 0 | 6 | 12 | 8 | 5 | 8 | 23 | 16 | 34 | 27 | 33 | 43 | 38 |
|
– | – | 0 | 1 | 4 | 2 | 5 | 18 | 14 | 27 | 21 | 27 | 38 | 33 |
|
– | – | – | 0 | 10 | 1 | 4 | 18 | 14 | 32 | 21 | 27 | 38 | 33 |
|
– | – | – | – | 0 | 3 | 4 | 19 | 14 | 31 | 24 | 30 | 41 | 35 |
|
– | – | – | – | – | 0 | 3 | 18 | 13 | 28 | 22 | 28 | 39 | 33 |
|
– | – | – | – | – | – | 0 | 19 | 14 | 29 | 24 | 30 | 41 | 35 |
|
– | – | – | – | – | – | – | 0 | 18 | 35 | 34 | 36 | 47 | 42 |
|
– | – | – | – | – | – | – | – | 0 | 29 | 28 | 30 | 41 | 39 |
|
– | – | – | – | – | – | – | – | – | 0 | 5 | 4 | 14 | 19 |
|
– | – | – | – | – | – | – | – | – | – | 0 | 6 | 17 | 18 |
|
– | – | – | – | – | – | – | – | – | – | – | 0 | 14 | 19 |
|
– | – | – | – | – | – | – | – | – | – | – | – | 0 | 23 |
|
– | – | – | – | – | – | – | – | – | – | – | – | – | 0 |
The species name is derived from the type host (carrier) insect of the nematode species,
Measurements have been summarized in Table 1.
Metastegostom bearing conspicuous and movable triangular or flint-shaped dorsal tooth with strongly sclerotized surface giving an appearance of an inverted V-shape in light microscopy in lateral view; pointed left subventral ridge with three minute adventitious denticles on a plate; pointed right subventral ridge, often with distinct distal adventitious denticle.
Metastegostom bearing large claw-like dorsal tooth; large claw-like right subventral tooth; ridge of left subventral denticles or cusps, varying in number and size, i.e., three large cusps, the tip of two lateral cusps sometimes split into two small tips. Dorsal and right subventral teeth movable. No movement observed for left subventral denticles.
The paired papillae and the phasmid are arranged as <v1, v2, v3d, co, v4, ad, ph, (v5, v6, v7), pd> according to the nomenclature of Sudhaus and Fürst von Lieven (2003), where v1 located about 1 CBD anterior to co; v2 and v3d close to, but clearly separated from each other and located at slightly anterior to co; v4 at less than 1 CBD posterior to co; ad laterally located at the midway between co and the root of tail spike or slightly posterior to the midpoint; ph subventrally located, opening in between ad and v5; ventral v5-v7 forming triplet just anterior to the root of tail spike; and subdorsal pd slightly posterior to v7.
The species-specific (diagnostic) characters are summarized in Table 4. The new species is characterized by the pointed left subventral ridge with three minute adventitious denticles on a plate; pointed right subventral ridge often bearing a distinct distal adventitious denticle in the stenostomatous form; a large claw-like right subventral tooth and a ridge of left subventral denticles or cusps varying in number and size, i.e., three large cusps, the tip of two lateral cusps which sometimes split into two small tips; and the relative position of the anterior four pairs of genital papillae, i.e., v1-v2 and v2-v4 are almost equal and v2 and v3d are separated (not adjusted to each other). In addition to the species-specific characters, the new species is molecularly characterized by the barcoding sequence (NCBI accession number MH114986).
The new species is both typologically and phylogenetically close to
The culture from which the type specimens were obtained was originally isolated by N. Kanzaki from an adult
Besides its type carrier and locality, the species was isolated from a millipede species,
One slide holotype male; two slides, each with paratypes one male and one female, 28530-28532, deposited in the University of California Riverside Nematode Collection (UCRNC), CA, USA. Two slides, each with paratypes one male and one female (SMNHType-8989 and 8990) deposited in the Swedish Natural History Museum, Stockholm, Sweden. Two slides, each with paratypes one male and one female (SMNK-NEMA-T-0143 and 0144) deposited in the Natural History Museum Karlsruhe, Germany. The strains are available as living cultures and as frozen stocks under culture codes RS5939 (type strain isolated from stag beetle) and RS5941 (millipede isolate) in the Department of Evolutionary Biology, MPI for Developmental Biology, Tübingen, Germany, and can be provided to other researchers upon request. The new species binomial has been registered in the ZooBank database (zoobank.org) under the identifier [urn:lsid:zoobank.org:act:A6797D55-6BDA-4AE6-BC5E-1D0D7A010808].
sp. n. (Figs 6 and 7; Tables 2, 4, and 5).
The species name is derived from the genus name of type host (carrier) of the nematode,
Measurements have been summarized in Table 2.
Metastegostom bearing conspicuous and movable triangular or flint-shaped dorsal tooth with strongly sclerotized surface giving an appearance of an inverted V-shape in light microscopy in lateral view; pointed left subventral ridge with three minute adventitious denticles on a plate; pointed right subventral ridge, often with distinct distal adventitious denticle.
Metastegostom bearing large claw-like dorsal tooth; large claw-like right subventral tooth; ridge of left subventral denticles or cusps, varying in number and size, (i.e., three large cusps), the tip of two lateral cusps often split into two small tips. Dorsal and right subventral teeth movable. No movement observed for left subventral denticles.
The paired papillae and the phasmid are arranged as <v1, (v2d, v3), co, v4, ad, ph, (v5, v6, v7), pd>, where v1 located at
The new species is characterized by the pointed left subventral ridge with three minute adventitious denticles on a plate, the right subventral ridge bearing distinct distal adventitious denticles in the stenostomatous form; a large claw-like right subventral tooth and three left subventral cusps, which sometimes split at the tip into two small denticles; and the relative position of the anterior four pairs of genital papillae, i.e. v1-v2d and v2d-v4 are almost equal and v2d and v3 are very close to each other. In addition, the new species is molecularly characterized by the barcoding sequence (NCBI accession number MH114987).
The new species is typologically similar to and a cryptic species group with several species in the
The culture from which the type specimens were obtained was originally isolated by M. Herrmann from an adult stag beetle,
One slide holotype male; two slides, each with paratypes one male and one female, 28521-28523, deposited in the UCRNC, CA, USA. Two slides, each with paratypes one male and one female (SMNHType-8983 and 8984) deposited in the Swedish Natural History Museum, Stockholm, Sweden. Two slides, each with paratypes one male and one female (SMNK-NEMA-T-0137 and 0138) deposited in the Natural History Museum Karlsruhe, Germany. The strain is available as living culture and as frozen stock under culture code RS5949 in the Department of Evolutionary Biology, MPI for Developmental Biology, Tübingen, Germany, and can be provided to other researchers upon request. The new species binomial has been registered in the ZooBank database (zoobank.org) under the identifier [urn:lsid:zoobank.org:act:6B6DE4C3-5F44-46ED-A8B4-E8CC3FBE0643].
sp. n. (Figs 8 and 9; Tables 3–5)
The species name is derived from Dr. Yousuke Degawa, a mycologist from the University of Tsukuba, who provided 400 live specimens of millipedes for the present study.
Measurements have been summarized in Table 3.
Metastegostom bearing conspicuous and movable triangular or flint-shaped dorsal tooth with strongly sclerotized surface giving an appearance of an inverted V-shape in light microscopy in lateral view; pointed left subventral ridge with three minute adventitious denticles on a plate; pointed right subventral ridge, often with distinct distal adventitious denticle.
Metastegostom bearing large claw-like dorsal tooth; large claw-like right subventral tooth; ridge of left subventral denticles or cusps, varying in number and size, (i.e., three large cusps), the tip of two lateral cusps sometimes split into two small tips. Dorsal and right subventral teeth movable. No movement observed for left subventral denticles.
The paired papillae and phasmid are usually arranged as <v1, (v2d, v3), co, v4, ad, ph, (v5, v6, v7), pd>, where v1 located at
The new species is characterized by the pointed left subventral ridge with three minute adventitious denticles on a plate, a right subventral ridge bearing a distinct distal adventitious denticle in the stenostomatous form; a large claw-like right subventral tooth and three left subventral cusps which sometimes split at the tip into two small denticles; and the relative position of the anterior four pairs of genital papillae, i.e., v1-v2d and v2d-v4 are almost equal and v2d and v3 are extremely close to each other, and sometimes the third pair is directed sublaterally forming v3d. In addition, the new species is molecularly characterized by the barcoding sequence (NCBI accession number MH114984).
The species forms a cryptic species-complex with several species in the
The culture from which the type specimens were obtained was originally isolated by N. Kanzaki from an adult millipede,
One slide holotype male; two slides, each with paratypes one male and one female, 28527-28529, deposited in the UCRNC, CA, USA. Two slides, each with paratypes one male and one female (SMNHType-8985 and 8986) deposited in the Swedish Natural History Museum, Stockholm, Sweden. Two slides, each with paratypes one male and one female (SMNK-NEMA-T-0141 and 0142) deposited in the Natural History Museum Karlsruhe, Germany. The strain is available as living culture and as frozen stock under culture code RS5938 in the Department of Evolutionary Biology, MPI for Developmental Biology, Tübingen, Germany, and can be provided to other researchers upon request. The new species binomial has been registered in the ZooBank database (zoobank.org) under the identifier [urn:lsid:zoobank.org:act:430C36BC-DD11-4CF5-A4F4-A1EF478CEFB8].
sp. n. (Figs 10 and 11; Tables 2,4, and 5).
The species name is derived from the type locality of the nematode, Hongkong, China.
Measurements have been summarized in Table 2.
Metastegostom bearing conspicuous and movable triangular or flint-shaped dorsal tooth with strongly sclerotized surface giving an appearance of an inverted V-shape in light microscopy in lateral view, the distal end pointed and curved to direct anteriorly; pointed left subventral ridge with three minute adventitious denticles on a plate; pointed right subventral ridge, often with one or more distinct distal adventitious denticle(s).
Cheilostomatal plates very thick. Anterior end of each plate rounded and elongated to project from stomatal opening, forming a small flap. Each cheilostomatal plate slightly inclined inwardly, giving an appearance that the whole stoma is narrowing anteriorly. Gymnostom with very thick cuticle, forming a short, ring-like tube being thicker posteriorly, and whole gymnostomatal ring widening anteriorly. Anterior end of gymnostom internally overlapping the posterior end of cheilostomatal plates. Thus, the cheilo and gymnostomatal regions form a barrel-shape in lateral view. Metastegostom bearing large claw-like dorsal tooth; large claw-like right subventral tooth; ridge of left subventral denticles or cusps, varying in number and size, (i.e., three large cusps), the tip of these cusps often split into three or more small tips, sometimes forming serrated plate. Dorsal and right subventral teeth movable. No movement observed for left subventral denticles.
The paired papillae and the phasmid are arranged as <v1, v2, v3d, co, v4, ad, ph, (v5, v6, v7), pd>, where v1 located at
This species is typologically distinctive from the other members of the
The culture from which the type specimens were obtained was originally isolated by M. Herrmann from an adult
One slide holotype male; two slides, each with paratypes one male and one female, 28518-28520, deposited in the UCRNC, CA, USA. Two slides, each with paratypes one male and one female (SMNHType-8981 and 8982) deposited in the Swedish Natural History Museum, Stockholm, Sweden. Two slides, each with paratypes one male and one female (SMNK-NEMA-T-0135 and 0136) deposited in the Natural History Museum Karlsruhe, Germany. The strain is available as living culture and as frozen stock under culture code RS5957 in the Department of Evolutionary Biology, MPI for Developmental Biology, Tübingen, Germany, and can be provided to other researchers upon request. The new species binomial has been registered in the ZooBank database (zoobank.org) under the identifier [urn:lsid:zoobank.org:act:C29A0FB6-D5C4-49D2-88D1-2596732974FB].
sp. n. (Figs 12 and 13; Tables 3-5).
The species name is derived from the genus name of type host (carrier) of the nematode,
Measurements have been summarized in Table 3.
Metastegostom bearing conspicuous and movable triangular or flint-shaped dorsal tooth with strongly sclerotized surface giving an appearance of an inverted V-shape in light microscopy in lateral view; pointed left subventral ridge with three minute adventitious denticles on a plate; right subventral plate with two distinct distal adventitious denticles.
Metastegostom bearing large claw-like dorsal tooth; large right subventral tooth forming various shaped ridge, i.e., the tip is split into two large ridges or multiple small denticles; ridge of left subventral denticles or cusps, varying in number and size, (i.e., three large cusps), the tip of two lateral cusps sometimes split into two small tips. Dorsal and right subventral teeth movable. No movement observed for left subventral denticles.
The paired papillae and the phasmid are usually arranged as <v1, (v2d, v3), co, v4, ad, ph, (v5, v6, v7), pd>, where v1 located at a little more than 1 CBD anterior to co; v2d and v3 close to, or almost overlapping to each other and located at slightly anterior to co; v4 slightly, less than 1/3 CBD posterior to co; ad laterally located at the midway between co and the root of tail spike; ph subventrally located just anterior to v5; ventral v5-v7 forming triplet just anterior to the root of tail spike; and subdorsal pd overlapping with, or slightly posterior to v7.
The culture from which the type specimens were obtained was originally isolated by N. Kanzaki from an adult millipede,
One slide holotype male; two slides, each with paratypes one male and one female, 28524-28526, deposited in the UCRNC, CA, USA. Two slides, each with paratypes one male and one female (SMNHType-8987 and 8988) deposited in the Swedish Natural History Museum, Stockholm, Sweden. Two slides, each with paratypes one male and one female (SMNK-NEMA-T-0139 and 0140) deposited in the Natural History Museum Karlsruhe, Germany. The strain is available as living culture and as frozen stock under culture code RS5937 in the Department of Evolutionary Biology, MPI for Developmental Biology, Tübingen, Germany, and can be provided to other researchers upon request. The new species binomial has been registered in the ZooBank database (zoobank.org) under the identifier [urn:lsid:zoobank.org:act:DB937AF5-0107-4C71-BEDC-8E92B332D368].
RNAseq libraries were prepared for all new species (presented in this study and the two accompanying manuscripts) and the 30
In contrast to many animal or plant groups, nematode taxonomy suffers from a paucity of morphological features, resulting in two major shortcomings. First, while nematodes are believed to represent the most species-rich phylum among animals with an estimated species number in the range of 1 to 10 million, less than 30,000 species are currently described (Lambshead, 1993). Second, little is known about the total number of species in most nematode taxa, because extinction and speciation processes are largely unknown and species catalogues are far from completion. In addition, many studies in nematode taxonomy rely on morphology and molecular barcode analysis only, but do not involve mating experiments, often because species cannot be kept in culture under laboratory conditions. In free-living and parasitic nematodes alike total species assessments are not available, neither at the taxonomic, nor the genetic level. Thus, the presumably largest animal phylum lacks a reasonable species and biodiversity assessment. As a result, the diversity and magnitude of nematode species often goes unnoticed in general zoology. Similarly, other than for organisms such as
In the genus
This study shows that East Asia represents a hotspot of