195
Two new nema ode species o he genus Zalonema (Desmodo ida,
Desmodo idae, Desmodo inae) om mang o e we lands, China
Yuzhen Chen1, Yuqing Guo1,2
1 Fishe ies College, Jimei Uni e si y, Xiamen 361021, China
2 Fujian P o incal Key Labo a o y o Ma ine Fishe y Resou ces and Eco-En i onmen , Jimei Uni e si y, Xiamen 361021, China
Co esponding au ho : Yuqing Guo ([email p o ec ed])
Copy igh : © Yuzhen Chen & Yuqing Guo.
This is an open access a icle dis ibu ed unde
e ms o he C ea i e Commons A ibu ion
License (A ibu ion 4.0 In e na ional – CC BY 4.0).
Resea ch A icle
Abs ac
Two new species o he genus Zalonema Cobb, 1920 we e iden i ied du ing a meio au-
nal su ey o mang o e sedimen in China. Zalonema eu ysbucca sp. no . is cha ac e -
ized by body leng h 1772–2309 µm, cu icle wi h ans e se annuli; cephalic se ae mea-
su ing 1–2 µm, and eigh subcephalic se ae (2–3 µm) a anged in a ci cle be ween he
cephalic se ae and he an e io ma gin o he amphid; amphideal o ea (4–4.5 u ns) lo-
ca ed la e ally on he main pos e io po ion o he cephalic capsule; buccal ca i y la ge
and cup-shaped, wi h wel e cheilo habdia in he es ibule, a cu icula ized do sal oo h,
and minu e en al oo h; males possess la e al and en al alae; spicule leng h (as a c)
abou 1.13–1.34 imes he anal body diame e (abd); a small cup-shaped p eanal sup-
plemen is p esen , and he en al ala exhibi po e-like dep essions a he soma ic se ae
posi ions. Zalonema cylind ibucca sp. no . is dis inguished by he ollowing cha ac e -
is ics: body leng h 1158–1451 μm; cu icle wi h ans e se annuli; ou cephalic se ae
(2–3 µm) and eigh subcephalic se ae (2–3 µm) a anged in sepa a e ci cula ows;
amphideal o ea wi h 3–3.5 u ns; cylind ical buccal ca i y con aining 12 cheilo habdia
a anged ci cula ly in he es ibule; a la ge do sal oo h loca ed nea he cheilo habdia
base and a small en al oo h a he buccal ca i y’s base; males possess bo h la e al
alae and en al ala, spicules measu ing 1.07–1.19 imes he anal body diame e (as
a c), a small cup-shaped p eanal supplemen p esen , and he en al ala exhibi small
po e-like dep essions a soma ic se ae posi ions.
Key wo ds: F ee-li ing ma ine nema ode, Hainan P o ince, mang o e, meio auna, new
species, axonomy, Zalonema eu ysbucca sp. no ., Zalonema cylind ibucca sp. no .
In oduc ion
Meio aunal sedimen s we e collec ed du ing a p elimina y su ey o he meio-
auna in mang o e mud la s adjacen o he ci ies o Danzhou and Sanya, Hain-
an P o ince, China. Nema odes a e he dominan g oup a hese wo mang o e
sampling s a ions, o which Zalonema Cobb,1920 is dominan genus, accoun -
ing o 5.5% and 26.9% o he abundance, espec i ely. Despi e hei ecological
p e alence, he axonomic knowledge o ee-li ing ma ine nema odes in Chi-
nese mang o e we lands emains limi ed, wi h ewe han 50 species eco ded
o da e (Chen e al. 2023; Zhu e al. 2023; Sun and Huang 2024).
Academic edi o : S e en Nadle
Recei ed:
10 July 2025
Accep ed:
18 Oc obe 2025
Published:
20 No embe 2025
ZooBank: h ps://zoobank.
o g/398AE9DB-879E-4CA2-BEB5-
D027203C69BE
Ci a ion: Chen Y, Guo Y (2025)
Two new nema ode species o he
genus Zalonema (Desmodo ida,
Desmodo idae, Desmodo inae)
om mang o e we lands, China.
ZooKeys 1260: 195–211. h ps://doi.
o g/10.3897/zookeys.1260.164776
ZooKeys 1260: 195–211 (2025)
DOI: 10.3897/zookeys.1260.164776
196
ZooKeys 1260: 195–211 (2025), DOI: 10.3897/zookeys.1260.164776
Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
The genus Zalonema Cobb,1920 belongs o he sub amily Desmodo inae
wi hin he amily Desmodo idae. I was ini ially es ablished as a amily by Cobb
based on he species Zalonema nudum Cobb, 1920. Ge lach (1963) conside ed
Zalonema o be one o he subgene a o Desmodo a and Zalonema nudum o
be a synonym o Desmodo a megalosoma S eine , 1918. La e , Ve schelde and
Vincx (1996) aised Zalonema o genus le el.
Zalonema is dis inguished om o he gene a o he sub amily Desmodo -
inae by he ollowing synapomo phies: (1) inely annula e cu icle lacking longi-
udinal s ia ions o la e al di e en ia ion; (2) well-de eloped, ounded iangu-
la cephalic capsule; (3) la ge mul ispi al amphideal o ea (≥2 u ns); and (4)
p esence o subcephalic se ae (Tchesuno 2013; Ve schelde and Vincx 1996;
Ve schelde e al. 1998). While he elonga ed body o m and annula ion pa e n
esemble hose o ep esen a i e gene a o he sub amily Spi iniinae Chi wood,
1936, Zalonema is unequi ocally di e en ia ed by i s dis inc cephalic capsule,
a s uc u e en i ely absen in Spi iniinae (Ve schelde and Vincx 1996).
Recen axonomic s udies ha e e ealed mo phological a iabili y wi hin
he genus, pa icula ly in he posi ion o subcephalic se ae. The diagnosis o
he genus by Ve schelde and Vincx (1996) s a ed ha he subcephalic se ae
a e loca ed in on o o a an e io edge o amphids, howe e se en ecen -
ly desc ibed species, i.e.: Zalonema i anicum Gha ahkhani, Pou jam, Leduc &
Ped am, 2021, Zalonema supplemen o um Gha ahkhani, Pou jam, Leduc & Pe-
d am, 2021, Zalonema g anda Fadee a, Mo dukho ich & Zog a , 2016, Zalone-
ma kamcha kaensis Fadee a, Mo dukho ich & Zog a , 2016, Zalonema ma iae
La azábal-Filho, Sil a & Es e es, 2015, Zalonema sesokoensis Leduc, 2022 and
Zalonema icen ei La azábal-Filho, Sil a & Es e es, 2015, demons a e sub-
cephalic se ae ei he aligned wi h, o pos e io o, he amphids (Leduc 2022).
Fu he mo e, Gha ahkhani e al. (2021) p oposed an in agene ic di ision o
Zalonema in o wo g oups based on he p esence (G oup I) o absence (G oup
II) o la e al o en al alae in he pos e io body egion o males. G oup I includ-
ed species wi h la e al and/o en al alae in he pos e io body o males, g oup
II species lack la e al o en al alae in he pos e io body egion o males.
In his s udy, wo new species o he genus Zalonema we e ound du ing a p e-
limina y su ey o he meio auna in mang o e mud la s o China and a e desc ibed.
Ma e ial and me hods
Sedimen samples we e collec ed om mang o e mud la s adjacen he ci ies
o Danzhou (19.77–19.78°N, 109.26–109.27°E) and Sanya (18.23°N, 109.62°E),
Hainan P o ince, China, and immedia ely p ese ed in 5% o maldehyde-seawa e
solu ion. Nema odes we e ex ac ed om he sedimen by decan a ion and/o Lu-
dox cen i uga ion in he labo a o y, and s ained wi h Rose Bengal o mo e han
24 h in he labo a o y (Wa wick e al. 1998). Sedimen sampling and nema ode ex-
ac ion we e pe o med as desc ibed in ou p e ious s udies (Chen e al. 2023).
Measu emen s a e in µm. Abb e ia ions a e as ollows: a = body leng h/
maximum body diame e ; b = body leng h/pha ynx leng h; c = body leng h/ ail
leng h; abd = anal body diame e ; cbd = co esponding body diame e ; bd =
ul al body diame e ; c’ = ail leng h/abd; V = ul a om he an e io end; V(%)
= posi ion o ul a as % o body leng h om an e io end, ha is, V/body leng h.
All holo ypes and pa a ypes a e deposi ed in Jimei Uni e si y, Xiamen, China.
197
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Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
Resul s
O de Desmodo ida De Coninck, 1965
Family Desmodo idae Filipje , 1922
Sub amily Desmodo inae Filipje , 1922
Genus Zalonema Cobb, 1920
Gene ic diagnosis. (modi ied om Leduc 2022): Body long, cylind ical, gold-
b own unde ligh mic oscope wi h glass-like o golden cephalic capsule. Cu-
icula annuli close oge he , usually wi hou o namen a ion. Cephalic capsule
ounded, iangula . Labial sensilla inconspicuous, 6+6, cephalic se ae ou , ol-
lowed by ou o eigh subcephalic se ae o papillae loca ed an e io ly, pos e i-
o ly, o a same le el as he amphids, amphideal o ea mul ispi al ( wo u ns o
mo e) loca ed on he cephalic capsule. Sho and small soma ic se ae a anged
in se e al longi udinal ows. Pha ynx cylind ical wi h py i o m basal bulb. Male
ep oduc i e sys em mono chic. Spicules sligh ly a ched, cu icula ized, wi hou
elum. Gube naculum sho , en al and/o la e al alae some imes p esen in
males ( en al ala some imes di icul o dis inguish). P ecloacal supplemen s
p esen o absen . Female ep oduc i e sys em didelphic, amphidelphic, wi h
e lec ed o a ies. Tail conical. Caudal gland duc s and spinne e conspicuous.
Zalonema eu ysbucca sp. no .
h ps://zoobank.o g/054D7601-E14B-4EF1-BDB3-757BEDE2E58F
Figs 1, 2; Tables 1, 2
Type ma e ial. Six males and i e emales we e collec ed om S a ion DZ in
Decembe , 2020. Holo ype: • ♂1 on slide DZ20201214 2L18. Pa a ypes: • ♂2
on slide DZ20201214 2L101, • ♂3 and ♀1 on slide DZ20201214 2L111, • ♂4
on slide DZ20201214 2L102, • ♂5 on slide DZ20201214 1L113, • ♂6 on slide
DZ20201214 2L117, • ♀2 and ♀3 on slide DZ20201214 2L18, • ♀4 on slide
DZ20201214 2L110, • ♀5 on slide DZ20201214 1L101.
Type locali y and habi a . All specimens we e collec ed om he muddy sed-
imen in he mang o e ese e o Xinying Po in Danzhou Ci y, Hainan P o ince,
China. The main mang o e species he e is B uguie a gymno hiza (L.) Lam.
Cha ac e is ics o su ace sedimen s o sampling s a ions a e shown in Table 1.
E ymology. The species’ name is om he La in (Eu ys = b oad) and e e s o
he la ge buccal ca i y.
Measu emen s. Mo phological cha ac e is ics we e obse ed and measu ed
unde a di e en ial con as mic oscopy (NIKON 80i) (Table 2).
Desc ip ion. Gene al cha ac e is ics: Golden-b own body elonga ed and cy-
lind ical, wi h blun and ounded an e io ex emi y and conical ail. Cu icle wi h
dis inc ine annuli a anged ans e sely om he pos e io ma gin o he cephal-
ic capsule o he ail, ending in a smoo h, non-annula ed ail ip app oxima ely
10 µm in leng h. Soma ic se ae sho , abou 1–2 µm in leng h, a anged in eigh
longi udinal ows, and each se a is connec ed o an epide mal gland. Cephalic
capsule consis s o wo pa s: an an e io labial egion, wi h a hinne cu icle; and
a main pos e io po ion, wi h a conspicuously hickened cu icle wi hou annula-
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Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
Figu e 1. D awing o Zalonema eu ysbucca sp. no . (la e al iew). A. Male ail egion, showing copula o y s uc u e,
en al ala and p eanal supplemen ; B. Male head end; C. Female head end; D. Female ail egion; E. Female body pa ,
showing o a ies; F. Female body. Scale ba s: 50 μm (A–D); 125 μm (E); 100 μm (F).
ions, which is abou 15–19 µm wide in males and abou 13–16 µm wide in e-
males. Inne labial sensilla no obse ed; six ou e labial sensilla a e papilli o m,
a anged in a ci cle; ou cephalic se ae a anged in a ci cle, abou 1–2 µm in
leng h, loca ed sligh ly o he back o he ex e nal labial sensilla; eigh subcephal-
ic se ae, abou 2–3 µm in leng h, a anged in a ci cle be ween he cephalic se ae
and he an e io ma gin o he amphid. La ge spi al amphideal o ea and ape -
199
ZooKeys 1260: 195–211 (2025), DOI: 10.3897/zookeys.1260.164776
Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
Figu e 2. Mic oscopic images o Zalonema eu ysbucca sp. no . (la e al iew). A. Male head egion, showing chei-
lo habdia in buccal ca i y; B. Male head egion, showing buccal ca i y, la ge do sal oo h and minu e en al oo h;
C. Male amphid; D. Male an e io egion, showing longi udinal ows o sho soma ic se ae; E. Male pha ynx and he
py i o m pos e io bulb; F. Male pos e io egion, showing la e al alae, he end o en al ala and he ail; G. Male pos-
e io egion, showing copula o y s uc u e, supplemen and en al ala; H. Female ul a; I. Female middle egion,
showing longi udinal ows o sho soma ic se ae; J. Female ail; K. Male o al body; L. Female o al body. Scale
ba s: 10 μm (A–D, G–I); 50 μm (E); 100 μm (F, J–L)
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Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
Table 1. Cha ac e is ics o su ace sedimen s o sampling s a ions.
S a ion Tempe a u e (°C) pH Salini y (‰)
DZ20201214 1L 23.5 6.0 28
DZ20201214 2L 26 6.5 30
Table 2. Indi idual measu emen s o Zalonema eu ysbucca sp. no . (in µm excep
o a ios).
Specimen Holo ype Pa a ypes a e age (minimum-maximum)
Cha ac e s ♂1 5 ♂♂ 5 ♀♀
Body leng h 1926 2029 (1898–2309) 1969 (1772–2161)
Subcephalic se ae cbd 23 26 (23–29) 23 (21–25)
Wid h o cephalic capsule 17 17 (16–19) 15 (13–17)
Leng h o cephalic se ae 21.4 (1–2) 1.5 (2–2)
Leng h o subcephalic se ae 3 2 (2–2) 2.5 (2–3)
Buccal ca i y dep h 34 38 (35–39) 37 (36–39)
Buccal ca i y diame e 15 16 (13–19) 13 (12–15)
Amphids om an e io end 7 9 (7–10) 7 (6–8)
Amphid diame e 17 17 (15–18) 16 (15–17)
Amphid cbd 33 37 (30–41) 31 (27–37)
Amphid diame e /Amphid cbd (%) 52 46 (38–57) 52 (44–58)
Amphid u ns 4.00 4.00 (4.00–4.00) 4.12 (4.00–4.50)
Ne e ing om an e io end 113 118 (106–134) 121 (110–132)
Ne e ing cbd 88 86 (75–96) 80 (73–88)
Pha ynx leng h 224 218 (195–235) 205 (196–214)
Pha ynx bulb diame e 76 76 (64–83) 66 (63–70)
Pha ynx cbd 99 98 (83–107) 93 (88–98)
Max. body diame e 110 109 (94–122) 101 (91–108)
abd 64 59 (48–68) 43 (38–48)
Tail leng h 100 95 (87–99) 125 (116–136)
c’ 1.57 1.61 (1.43–1.82) 2.95 (2.39–3.41)
Spicule leng h as cho d 67 65 (56–69) -
Spicule leng h as a c 76 73 (63–81) -
Spicule leng h as a c/abd 1.19 1.25 (1.13–1.34) -
Leng h o la e al alae 566 553 (505–611) -
Leng h o gube naculum 34 31 (28–34) -
V- - 986 (903–1100)
bd - - 94 (86–104)
V(%) - - 50 (48–51)
a17.51 19.11 (16.19–20.63) 19.59 (16.41–21.96)
b8.60 9.54 (9.30–10.64) 9.61 (8.31–10.87)
c19.30 21.85 (21.07–23.65) 15.71 (14.55–16.67)
u e, 4–4.5 u ns, loca ed la e ally on he main pos e io po ion o he cephalic
capsule, wi h a diame e o abou 38–58% o cbd. Buccal ca i y la ge, wi h a max-
imum diame e o abou 12–19 µm and a dep h o abou 34–39 µm. The e a e 12
cheilo habdia a anged in a ci cle in he buccal ca i y es ibule; he inne wall o
he buccal ca i y is scle o ized, wi h wo ee h: one la ge do sal oo h loca ed a
abou one- hi d o hal he dep h o he buccal ca i y, and one small en al oo h
a he bo om o he buccal ca i y. Cylind ical pha ynx wi h cu icula ized lumen
and py i o m pos e io bulb; inne wall o he pha ynx is hickened o scle o ized,
and he pha yngeal bulb is b oken in o wo pa s. Ne e ing loca ed a 50–63%
o he leng h o he pha ynx. Sec e o y-exc e o y sys em no obse ed.
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Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
Males: la e al alae p esen on bo h sides o pos e io body pa , ex ending
om 505–566 µm in on o anus o a posi ion on ei he side o he body a he
anus. Ven al ala p esen , ex ending om 250–356 µm in on o anus o he
anus. Rep oduc i e sys em mono chic wi h single an e io ou s e ched es is
loca ed o he igh o in es ine. Spicules pai ed, equal, a cua e, leng h 1.13–
1.34 imes abd as a c, wi h p oximal capi ulum, wi hou elum. Gube naculum
simple, wi hou apophyses. A small cup-shaped p eanal supplemen loca ed
abou 13 µm an e io o he anus. The su ace o he en al ala is ma ked by
small po e-like dep essions loca ed a he posi ions co esponding o soma -
ic se ae. Howe e , no dis inc se al s uc u es we e obse ed wi hin hese de-
p essions. These s uc u es appea o co espond o he “small, po e-like, no
cu icula ized” ea u es epo ed by Leduc (2022). In he p esen s udy, hese
po e-like dep essions we e clea ly obse ed o be a anged egula ly along he
en al ala, ex ending an e io ly along he body, and aligning wi h he pa e n o
soma ic se ae in egions whe e en al ala a e absen . In addi ion, each po e-
like dep ession ex ends subcu aneously and connec s o he epide mal gland,
simila o he associa ion seen in soma ic se ae. The e o e, we in e p e hese
po e-like s uc u es on he en al ala no as p eanal supplemen s, bu likely
as po e-like sensilla ha may be homologous o soma ic se ae. P eanal se ae
no obse ed. Conical ail wi hou e minal se ae, leng h abou 1.43–1.82 imes
abd. Spinne e wi h single opening p esen .
Females: Mos cha ac e is ics a e simila o hose o he males, bu he
ail is longe han ha o he males, wi h a leng h o abou 2.4–3.4 imes abd.
Wi hou la e al alae o en al ala. Rep oduc i e sys em didelphic, e lexed
and p esen on he igh side o he in es ine. Vul a scle o ized, loca ed a
48–51% o he body leng h.
Diagnosis. Zalonema eu ysbucca sp. no . is dis inguished by he ollowing
combina ion o cha ac e s: golden-b own body (leng h 1772–2309 µm) wi h a
inely annula e cu icle; sho soma ic se ae a anged in eigh longi udinal ows;
eigh subcephalic se ae (2–3 µm) a anged in a ci cle be ween he cephalic se-
ae (1–2 µm) and he amphid’s an e io ma gin; amphideal o ea (4–4.5 u ns)
loca ed la e ally on he cephalic capsule’s pos e io po ion (diame e 38–58%
o cbd); a la ge, cup-shaped buccal ca i y wi h wel e cheilo habdia, a cu icula -
ized do sal oo h, and a minu e en al oo h; and a conical ail. Males possess
la e al and en al alae; he a cua e spicules measu e 1.13–1.34 imes he anal
body diame e (abd); gube naculum simple wi hou apophyses; a small cup-
shaped p eanal supplemen , and he su ace o he en al ala a he posi ion
o he soma ic se ae sunken in o small po e-like dep essions.
In acco dance wi h he classi ica ion p oposed by Gha ahkhani e al. (2021),
he new species Zalonema eu ysbucca sp. no . belongs o G oup I, which is cha -
ac e ized by he p esence o la e al alae and/o en al ala on he pos e io pa
o he male body. Zalonema eu ysbucca sp. no . is dis inguished by he combined
p esence o bo h la e al and en al alae, con as ing wi h Zalonema di le seni
(Micole zky, 1922) Ge lach, 1963 and Zalonema megalosoma (S eine , 1918) Ge -
lach, 1963, which possess only la e al alae and lack a en al ala (in con as o
Gha ahkani’s classi ica ion ha places Zalonema megalosoma in G oup II, he e-
desc ip ion o his species by Ge lach (1963) epo s he p esence o la e al alae
in males); and om Zalonema my ianae Ve schelde & Vincx, 1996, which lacks
la e al alae bu possesses en al ala. Zalonema eu ysbucca sp. no . can also be
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Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
di e en ia ed om o he species in G oup I. Zalonema eu ysbucca sp. no . di -
e s om Zalonema ma iae La azábal-Filho, Sil a & Es e es, 2015 in ha ing eigh
subcephalic se ae ( s ou ), a cup-shaped buccal ca i y wi h a single la ge do sal
(a 30–50% dep h) and small en al ee h ( s. elonga e buccal ca i y wi h wo
do sal ee h, one a e he o he ), and spicules lacking a elum (La azábal-Filho
e al. 2015); om Zalonema icen ei La azábal-Filho, Sil a & Es e es, 2015 in he
subcephalic se ae posi ion (be ween cephalic se ae and he an e io ma gin o
he amphid s. a amphid pos e io ma gin) and numbe (8 s. 4) (La azábal-Fil-
ho e al. 2015); om Zalonema i anicum Gha ahkhani, Pou jam, Leduc & Ped am,
2021 in he den al o mula (one do sal and one en al oo h s 3 ee h, a la ge
an e io do sal oo h, a small pos e io do sal oo h, and a medium-sized en-
al-sub en al oo h) (Gha ahkhani e al. 2021); om Zalonema supplemen o um
Gha ahkhani, Pou jam, Leduc & Ped am, 2021 in he subcephalic se ae coun (8
s 4) and amphid coils (4–4.5 s 3 u ns) (Gha ahkhani e al. 2021); and om
Zalonema sesokoensis Leduc, 2022 by lacking amphid sexual dimo phism and
possessing a la ge buccal ca i y (Leduc 2022).
Zalonema cylind ibucca sp. no .
h ps://zoobank.o g/D9F11052-B88B-4498-AA92-82C0BBF8BA33
Figs 3, 4; Table 3
Type ma e ial. Fi e males and h ee emales we e collec ed om S a ion SY in
July, 2020. Holo ype: • ♂1 on slide SY2020730 2H108. Pa a ypes: • ♂2 & ♀1 on
slide SY2020730 1L126, • ♂3 & ♀2 on slide SY2020730 2H102, • ♂4, • ♂5 & ♀3
on slide SY2020730 2H108.
Type locali y and habi a . All specimens we e collec ed om he muddy sed-
imen in he mang o e ese e o Yalong Bay Qingmei Po in Sanya Ci y, Hain-
an P o ince, China. The p ima y mang o e species he e a e Rhizopho a s ylosa
G i . and A icennia ma ina (Fo ssk.) Vie h.
E ymology. The species is name o i s cylind ical buccal ca i y.
Measu emen s. Mo phological cha ac e is ics we e obse ed and measu ed
unde a di e en ial con as mic oscopy (NIKON 80i) (Table 3).
Desc ip ion. Gene al cha ac e is ics: Body elonga e-cylind ical, golden-b own
in colo , wi h a cephalic capsule and a conical ail. Cu icle wi h annuli a anged
ans e sely om he pos e io ma gin o he cephalic capsule o he ail, wi h
ail ip abou 10 µm smoo h and wi hou annuli. The annuli a e spaced by abou
0.6 µm a bo h he an e io and pos e io ends o he body, and by abou 0.8 µm
in he middle pa . Soma ic se ae sho , 1–2 µm in leng h, and a anged in eigh
longi udinal ows. Cephalic capsule di ided in o wo pa s: an an e io labial e-
gion, wi h a hinne cu icle; and a main pos e io po ion, wi h a wid h o 8–10
µm, and i s cu icle dis inc ly hickened wi hou annuli. No inne labial sensilla
we e obse ed; he six ou e labial sensilla a e papilli o m and a anged in a
ci cle; ou cephalic se ae and eigh subcephalic se ae a e each a anged in a
ci cle, abou 2–3 µm in leng h, wi h he cephalic se ae loca ed sligh ly pos e io
o he ou e labial sensilla; he subcephalic se ae a e posi ioned be ween he
cephalic se ae and he an e io ma gin o he amphid. La ge spi al amphideal
o ea and ape u e, 3–3.5 u ns, loca ed la e ally on he main pos e io po ion
o he cephalic capsule, wi h diame e abou 35–41% o cbd. Buccal ca i y cylin-
203
ZooKeys 1260: 195–211 (2025), DOI: 10.3897/zookeys.1260.164776
Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
d ical, wi h a maximum diame e o app oxima ely 5–6 µm and a dep h o abou
28–31 µm. The e a e 12 cheilo habdia a anged in a ci cle in he buccal ca i y
es ibule. A he an e io pa o he buccal ca i y, nea he base o he cheilo -
habdia, he e is a la ge do sal oo h; and ano he small en al oo h is loca ed a
he bo om o he buccal ca i y, close o he esophagus. Cylind ical pha ynx wi h
cu icula ized lumen and a pea -shaped pos e io bulb; he inne wall o he pha -
ynx is hickened o scle o ized, and he pha yngeal bulb sligh ly b oken. Ne e
ing loca ed a 60–65% o he pha ynx. The exc e o y sys em was no obse ed.
Figu e 3. D awing o Zalonema cylind ibucca sp. no . (la e al iew). A. Male head end; B. Male ail egion, showing cop-
ula o y s uc u e, en al ala and p eanal supplemen ; C. Female ail egion; D. Female head end; E, F. Male copula o y
s uc u e; G. Female body; Scale ba s: 50 μm (A–F); 100 μm (G).
210
ZooKeys 1260: 195–211 (2025), DOI: 10.3897/zookeys.1260.164776
Yuzhen Chen & Yuqing Guo: New nema ode species o Zalonema om mang o e we land o China
Con lic o in e es
The au ho s ha e decla ed ha no compe ing in e es s exis .
E hical s a emen
No e hical s a emen was epo ed.
Use o AI
No use o AI was epo ed.
Funding
This esea ch was unded by he Na ional Na u al Science Founda ion o China (g an
numbe 31772416), and he Na u al Science Founda ion o Fujian P o ince (g an num-
be 2022J01324)
Au ho con ibu ions
Me hodology, axonomy and w i ing o iginal d a : Y.C.; p ojec managemen , wo k
p og am: Y.G.
Au ho ORCIDs
Yuzhen Chen h ps://o cid.o g/0009-0009-8953-0756
Yuqing Guo h ps://o cid.o g/0000-0002-9177-0144
Da a a ailabili y
All o he da a ha suppo he indings o his s udy a e a ailable in he main ex .
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