Lanzavecchia mangrovi, Gagarin, Vladimir G., 2014

Gagarin, Vladimir G., 2014, Lanzavecchia mangrovi sp. n. (Nematoda, Dorylaimida) from mangroves of Red River Estuary, Vietnam., Zootaxa 3764 (4), pp. 489-494 : 490-494

Lanzavecchia mangrovi sp. n.

( Figs 1 , 2 ; Table 1 )

Type material. Holotype male, slide reference number 102/24, deposited in the RAS Helminthological Museum, Institute of Ecology and Evolution, Center for Parasitology, Russian Academy of Sciences (Moscow, Russia).

Paratypes. Two males and one female deposited in the RAS Helminthological Museum, Institute of Ecology and Evolution, Center for Parasitology, Russian Academy of Sciences (Moscow, Russia); six males and three females deposited in the collection of the Department of Nematology of the Institute of Ecology and Biological Resources ( JEBR), Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Rd., Hanoi, Vietnam.

Measurements. Table 1 .

Type locality. North Vietnam, Nam Dinh Province, Red River Delta, Xuan Thuy National Park, mangroves. Latitude: 20º13, 672? N, Longitude: 106º31, 324 E. Depth 25 cm, silt, salinity 27.0 ‰. Collected on 30 October 2012.

Etymology. The specific epithet means “mangroves”, “from mangrove thickets”.

Description. Male. Body comparatively long and thin, tapering toward both extremities. Cuticle smooth, 3.0– 3.5 µm thick at mid-body. Lateral pores not visible. Lips amalgamated, labial and cephalic papillae barely visible. Labial region well set off. Amphidial fovea cup-like, wide, occupying 65–78 % of the corresponding body diameter and situated at the base of lips. Odontostyle long, thin and slightly curved, 1.6–1.9 times the labial region diameter, its aperture constituting only 10–15 % its length. Odontophore rod-like, 0.8–1.0 times as long as odontostyle length. Guiding ring unitary, single. Pharynx divided into two portions. Anterior portion thin, poorly muscular, posterior portion thicker, muscular, occupying 41–46 % of pharynx length. Pharyngeal gland nuclei indistinct. Cardia conoid, muscular, surrounded with intestinal tissue.

Testes paired, opposed, situated to the left of intestine; anterior testis outstretched, posterior testis reflexed. Vas deferens well developed. Spicules dorylaimoid, 1.5–1.8 cloacal body diameters long, with two spindle-shaped guiding pieces. In addition to adanal pair, a series of 29–32 contiguous ventromedial supplements are present. Prerectum very long, well developed, 13.1–18.2 cloacal body diameter long, intestine-prerectum junction anterior to anteriormost supplement. Tail long, with proximal conical and distal thin, whip-like portions, gradually merging into one another. Distal portion of this tail is 0.9–1.2 times as long as its proximal portion. Tail bearing 3–4 pairs of caudal papillae.

Female. General morphology is similar to that of males in structure of cuticle and anterior body end. Cuticle smooth. Lips amalgamated. Labial region well set off. Amphidial fovea cup-like, wide, situated at the base of lips.

Odontostyle long, thin and slightly curved. Odontophore rod-like, 0.9–1.1 times as long as odontostyle length. Guiding ring unitary, single. Pharynx divided into two portions. Anterior portion thin, poorly muscular, posterior portion thicker, muscular, occupying 41–43% of pharynx length. Prerectum 12.3–17.5 anal body diameters long. Rectum 0.9–1.2 times as long as anal body diameter. Reproductive system didelphic, amphidelphic; ovaries antidromous, reflexed Vulva a transverse slit, pre-equatorial. Vulva lips not sclerotized, not protruding outside the body contour. Oocytes numerous, first in two rows, then a single row. Uterus spacious, containing two to four eggs, measuring 113–135 x 43 –60 µm. Vagina extending to half of the corresponding body diameter, with muscular walls. Tail long, with proximal conical and distal thin, whip-like portions, gradually merging into one another. Distal portion of this tail 1.8–2.3 times as long as its proximal portion.

Diagnosis. Body long and thin (L = 2708–3755 µm, a = 39–51). Cuticle smooth. Lips amalgamated; labial region well off set. Odontostyle long, very thin and slightly curved, 23–25 µm long; its aperture constituting 10–15 % its length. Odontophore 21–24 µm long. Guiding ring unitary, simple. Pharynx divided into two portions: anterior portion thin, poorly muscular, posterior portion thicker, muscular, occupying 41–41% of pharynx length. Vulva a transverse slit, pre-equatorial. Uterus spacious, with numerous spermatozoa and 2– 4 eggs, measuring 113– 135 x 43 –60 µm. Spicules 63–65 µm long, 29–32 contiguous ventromedian supplements. Prerectum in males long, well developed, 13.1–18.2 cloacal body diameter long; intestine-prerectum junction always anterior to anterior most supplement. Tail long, with proximal conical and distal thin, whip-like portions, gradually merging into one another. Distal portion 1.0–2.3 times as long as its proximal portion.

Differential diagnosis. The genus Lanzavecchia Zullini, 1988 currently contains 2 valid species: L. fafner Zullini, 1988 and L. coomansi ( Nicholas & Stewart, 1984) Andrássy, 2009 ). L. fafner was found in Lake Zway, Ephiopia ( Zullini, 1988). With a body length of 7.56–8.08 mm, L. fafner is much longer than L. mangrovi .

Lanzavecchia mangrovi sp. n. is similar to L. coomansi , found in mangroves in Australia ( Nicholas & Stewart, 1984), but differs in the longer body (L = 2.71–3.76 mm versus L = 2.2–2.9 mm in L. coomansi ), shorter spicules (63–65 µm versus 72–88 µm in L. coomansi ), longer prerectum (500–675 µm versus 262–310 µm in L. coomansi ) and shorter distal portion of tail in relation to its proximal portion (0.6–0.8 versus 0.9–2.3 in L. coomansi ) ( Nicholas, Stewart, 1984).

Figures

FIGURE 1. Lanzavecchia mangrove sp. n., holotype male and paratype female. A: female, entire body; B: male, entire body; C: male, head; D: male, anterior body end; E: vulva region; F: Female, posterior body end; G: male posterior body end. Scale bars: A, b = 300 µm, D, E = 80 µm; F, G = 60 µm; C = 20 µm.

FIGURE 2. Lanzavecchia mangrove sp. n., paratypes male and female. A: male, entire body; B: male, head; C: male, anterior body end; D: female, vulva region; E: female, posterior body end; F: male, posterior body end. Scale bars: A = 250 µm; E = 100 µm; C, D, F = 50 µm; B = 20 µm.

Tables

TABLE 1. Morphometrics of Lanzavecchia mangrovi sp. n. (all measurements are given in µm unless otherwise stated, expect for the ratios a, b, c, c’, V and n. sup.)

Character	Holotype male	Paratype males	Paratype females
n	1	9	4
L	3103	2994±125 (2815–3158)	3176±381 (2708–3755)
a	40	44±4 (39–50)	46±4 (41–51)
b	11.0	10.1±0.6 (9.3–11.0)	11.2±1.1 (9.8–12.7)
c	29.3	28.4±1.9 (24.7–30.3)	26.4±2.9 (22.0–30.0)
c’	2.6	2.6±0.2 (2.2–3.0)	3.4±0.3 (2.9–3.7)
V	–	–	46.2±2.2 (42.4–47.9)
diam.c.s	14	13±1 (13–14)	14±1 (13–14)
diam.midb.	77	69±7 (58–77)	69±14 (56–90)
a.d.	41	41±3 (36–47)	36±4 (30–41)
ods.	25	24±1 (23–25)	23±1 (23–24)
odph.	23	23±1 (21–24)	24±1 (23–24)
ph.l.	281	297±18 (263–322)	277±17 (250–293)
bul.l.	130	128±9 (113–144)	116±3 (113–119)
dis.ph.cl.	2716	2592±117 (2435–2759)	–
dis.ph.v.	–	–	1155±161 (933–1229)
dis.v.a.	–	–	1625±217 (1405–1985)
t.l.	106	105±6 (95–115)	119±10 (104–131)
pr.l.	567	599±35 (563–675)	517±56 (500–603)
spic.	65	64±1 (63–65)	–
n.sp.	32	31±1 (29–32)	–
l.sup.r.	117	112±5 (106–117)	–