Three new free-living marine nematode species of Subsphaerolaimus Lorenzen, 1978, Halichoanolaimus de Man, 1886 and Belbolla Andrássy, 1973 from mangrove wetlands in Taiwan Author Xiao, Yueping 0000-0002-9177-0144 State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Fisheries College, Jimei University, Xiamen 361021, P. R. China guoyuqing @ jmu. edu. cn; https: // orcid. org / 0000 - 0002 - 9177 - 0144 & https: // orcid. org / 0009 - 0001 - 3569 - 3068 guoyuqing@jmu.edu.cn Author Guo, Yuqing 0000-0002-9177-0144 State Key Laboratory of Mariculture Breeding, Fisheries College of Jimei University Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment, Fisheries College, Jimei University, Xiamen 361021, P. R. China guoyuqing @ jmu. edu. cn; https: // orcid. org / 0000 - 0002 - 9177 - 0144 guoyuqing@jmu.edu.cn text Zootaxa 2023 2023-11-02 5361 3 301 322 https://www.mapress.com/zt/article/download/zootaxa.5361.3.1/52193 journal article 10.11646/zootaxa.5361.3.1 1175-5326 10146950 2AF3B0AE-C2E4-41D5-9C61-3A688B9D5FCD Morphological description of Belbolla forkyspicula sp. nov. urn:lsid:zoobank.org:act: FEF8DFCF-FB96-485C-8C06-A0F7F920E93A ( Figures 6–7 , Table 5 ) Type material. Three males and four females were collected from station GNTH 1 in February 2021 . Holotype : ♁1 on slide number GNT20210221 H15. Paratypes : ♁2–3 on slide number GNT20210221 H131, ♀ 1 on slide number GNT20210221 H139, ♀ 2 on slide number GNT20210221 H131, ♀ 3 on slide number GNT20210221 H136 and ♀ 4 on slide number GNT20210221 H140. Type locality and habitat. All specimens were collected from a mangrove ( Avicennia marina ) forest in Guningtou, Jinmen County. Station JMGNT: 118°18'15.84″E , 24°29'9.24″N . Etymology. Species epithet refers to the shape of the spicules: like a fork. TABLE 5. Individual measurements and morphological statistics of Belbolla forkyspicula sp. nov. (in μm).

Characteristics	Holotype ♁1	♁2	♁3	Paratypes ♀1 ♀2		♀3	♀4
Body length	1510	1512	1443	1492	1477	1675	1582
Head diameter	10	10	9	8	9	8	8
Cephalic setae length	6	7	6	5	10	5	5
Cervical setae length	5–14	5–13	5–15	5–7	5–7	6–7	5–7
Buccal cavity length	11	11	11	11	6	11	11
Buccal cavity diameter	5	6	5	6	6	6	6
Nerve ring from the anterior end	231	232	232	226	218	251	205
Nerve ring body diameter	45	39	41	41	44	42	35
Pharynx length	384	409	404	419	404	439	422
Pharynx body diameter	56	48	53	52	67	55	55
Maximum body diameter	59	56	57	57	82	65	62
Anal body diameter	30	26	26	27	30	30	27
Tail length	109	121	114	99	98	112	104
c’	3.6	4.7	4.3	3.7	3.3	3.8	3.9
Spicule length as arc	32	38	31	-	-	-	-
Spicule length as chord	32	37	30	-	-	-	-
Length of gubernaculum	13	14	13	-	-	-	-
Number of supplements	2	2	2	-	-	-	-
Distance to the vulva from the anterior end of the body	-	-	-	862	821	932	909
Vulval body diameter	-	-	-	63	80	63	62
V%	-	-	-	58	56	56	58
a	25.8	27.1	25.2	26.2	18.0	26	25.5
b	3.9	3.7	3.6	3.6	3.7	3.8	3.8
c	13.9	12.5	12.6	15.1	15.1	15.0	15.2

Description Males. Body is medium in length, tapering slightly towards the extremities, anterior body region outstretched anteriorly and strongly tapered anteriorly from the mid-pharynx to head region. Cuticle smooth, without longitudinal ridges and transversely striated. Head diameter 9–10 μm and distinctly narrowing. Inner labial sensilla papilliform, six small papillae and ten cephalic setae (6–7 µm long) arranged in one circle. Dozens of cervical setae, with the anterior cervical setae (12–15 µm long) in one circle, and the others arranged irregularly. Amphidial fovea not observed. Buccal cavity waist drum-shaped, 11 μm deep and 5–6 μm wide, separated into two buccal chambers by a cuticular ring, which is smooth without denticles. Buccal cavity with one large right dorsolateral tooth and two less prominent teeth, which are dorsal and left ventrolateral in position. Nerve ring at 57–60% of the pharynx length. Pharynx is composed of two different parts. Anterior cylindrical, muscular; the posterior part consisting of seven pharynx bulbs, each of which has a cuticle cavity. Renette cell and excretory pore not observed.Cardia small, surrounded by intestinal tissue. Tail short, with a slightly swollen tip, with six terminal setae, 7–8 μm long. Caudal glands present. FIGURE 6. Belbolla forkyspicula sp. nov. A: Lateral view of the male anterior part. B: Lateral view of the female anterior part. C: Lateral view of the male head part. D: Lateral view of the female head part. E: Spicule of the male. F: Lateral view of the male posterior part. G: Lateral view of the female posterior part. H: Lateral view of the female reproductive system. Scale bars: A, B, F, G = 25 μm; C, D, E = 10 μm; H = 50 μm. FIGURE 7. Belbolla forkyspicula sp. nov A: Lateral view of the male anterior part; B: Lateral view of the female anterior part; C: Lateral view of the male head end; D: Lateral view of the female head end; E: Lateral view of the male posterior part; F: Lateral view of the female posterior part; G: Spicule of the male; H: Supplement of the male; I: Lateral view of the female reproductive system. Scale bars: A, B, E, F, I = 25 μm; C, D, G, H, J = 5 μm. TABLE 6. Morphometrics of males of valid species of the genus Belbolla . Note: “-” indicates that data are missing; “*” indicates that data are from pictures in the literature.

Species	Body length	Buccal cavity length	Cephalic setae length	Cervical setae length	Number of oesophageal bulbs	Tail length	a	b	c	c’	Spicule length	Gubernaculum apophysis length	Number of precloacal supplements
B. asupplementata Juario, 1974	2053–2060	10.4– 11.0	5.6–6.2	5*	7	167	42–51.6	3.6–3.7	12.3–13.5	5.6	38.9–39.8	8.2–9.0	0
B. californica ( Allgén, 1951 ) Andrássy, 1973	2390	-	-	-	7–9	-	-	-	-	-	68	21	2
B. forkyspicula sp. nov	1443–1512	11	6–7	5–15	7	109–121	25.2–27.1	3.6–3.9	12.5–13.9	3.6–4.7	31–38	13–14	2
B. gallanachmorae ( Inglis, 1961 ) Andrássy, 1973	2900	14	10	16–21	8	234	34.9	4	12.4	4.8	69	14	2
B. gracilis Gagarin & Nguyen Vu Thanh, 2016	911	12	6–7	6–7*	7	135	31	9	6.7	6	50	14	2
B. heptabulba Timm, 1961	1130–1160	9	6.5	9	7	-	25–29	3.4–3.7	11.8–14.7	4.3	30–34	absent	2
B. huanghaiensis Huang & Zhang, 2005	3037–3700	16–17	11.5–13	22–27	9	230–252	34.5–41.9	3.9–4.5	12.8–14.8	3.8–4.2	106–137	45–60	2
B. intarma Belogurov & Belogurova, 1980	3700	-	-	-	9	215	-	-	-	-	144	-	2
B. longispiculata Nasira, Shahina & Shamim, 2014	2638	14	8	5	8	204	32.97	4.7	12.9	4.3	216	20	5

...Continued on the next page TABLE 6. (Continued)

Species	Body length	Buccal cavity length	Cephalic setae length	Cervical setae length	Number of oesophageal bulbs	Tail length	a	b	c	c’	Spicule length	Gubernaculum apophysis length	Number of precloacal supplements
B. stenocephalum Huang & Zhang, 2005	2226–2394	16–18	9–11	20–21	8	176–210	33.2–36.3	3.7	10.6–12.6	3.5–4.1	80–100	34–36	2
B. sundaensis ( Micoletzky, 1930 ) Andrássy, 1973	♀=2640	-	-	-	8	-	-	-	-	-	-	-	2
B. teissieri Luc & De Coninck, 1959	1899	11	7	16	8	162	36.5	3.7	11.7	5.8	39	14	3
B. tenuidens ( Cobb, 1920 ) Andrássy, 1973	2700	-	-	-	8	-	-	-	-	-	-	-	2
B. vietnamica Gagarin & Nguyen Dinh Tu, 2016	1057–1091	10–11	2.5–3	4–5	4	140–146	22–25	3.7–3.8	7.5–7.6	4.9–5.2	55–56	9–10	4
B. warwicki Huang & Zhang, 2005	1470–1772	9	5.5–7	13–15	7	116–140	39.4–45.4	3.4–3.9	12.5–12.7	4.8–5.6	33–37	7–8	2
B. wonkimi Rho, Lee, Lee & Min, 2020	3263–3396	16–17	10–11	24–25	9	265–299	33–35	4–5	11–13	3.7–4.3	115–130	17–18	2
B. sinica Wang, Guo & Wang, 2022	1405	9	7	7	7	101	36.0	3.9	13.9	3.6	36	9	2
B. zhangi Guo & Warwick, 2001	2230–2750	12–18	8–10	18–22	8	170–210	29.3–35.4	4.1–4.7	13.1–13.5	2.9–3.7	56– 74chord	40–45	2

Two testes, opposite and outstretched. Anterior testis to the left and posterior testis to the right of the intestine. Spicules 31–38 µm in length, paired, equal and arcuated. Proximal end fork-like, distally tapered. Gubernaculum small, slightly protruding, 13–14 μm long. Two winged precloacal supplements strongly developed, anterior precloacal supplement 14–15 μm long, posterior precloacal supplement 16–17 μm long. Posterior precloacal supplement 130–158 μm from the cloacal opening, and the distance between the two supplements is 59–78 μm. One pair of setae located just in front of the cloaca, approximately 5 µm long. Females. Similar to male in general characteristics, but with a shorter tail (109–121 μm vs. 98–104.1 μm; c : 12.5–13.9 vs. 15.0–15.2) and without long cervical setae or terminal setae. Reproductive system amphidelphic, ovaries outstretched.Anterior gonad to the left and posterior gonad to the right of the intestine. Vulva at 55.6–57.8% of the body length. Short vagina with thick walls perpendicular to the longitudinal body axis.