Spirinia elongata, sp. nov. (Nematoda, Desmodoridae) from Pina Basin, Pernambuco, Brazil
Author
Castro, Francisco José Victor De
Author
Bezerra, Tânia Nara Campinas
Author
Silva, Maria Cristina Da
Author
Fonsêca-Genevois, Verônica
text
Zootaxa
2006
2006-02-02
1121
1121
53
68
journal article
11755334
2AFC2556-048E-47B2-9B2A-4CD480C622B9
Species:
Spirinia elongata
sp. nov.
Male
Cylindrical elongated body with rounded head and conical tail (L=
1368–2079 µm
). The cuticle is annulated (
0.67–1µm
) less obvious in the head region than in the tail. The internal labial sensilla are not visible. Six papilliform labial sensilla, four cephalic setae and four subcephalic setae present. The cephalic setae
3–5 µm
are placed laterally on the median portion of amphideal fovea. The subcephalic setae
3.5–5 µm
are situated on the neck region, posterior to the amphids. The somatic setae are shorter
2.5–4 µm
present up to bulb region. The amphideal fovea is ventrally rounded in “loop” with external circular line. The buccal cavity has one very small subventral tooth and two small dorsal teeth and, that are dificult to see. The muscular pharynx has a developed terminal bulb occupying 62–86 % of the total corresponding body width, with cuticularized lumen and median plasmatic interruption. The nerve ring occupies 52–63 % of the total pharynx length. The specimens possess one anterior testis in to the left of intestine. The spicules are curved
52– 67 µm
and the capitulum developed and velum sclerotized. The gubernaculum
24–28 µm
is a laminarlike shape and enveloped by the distal portion of spicule. One pair of seta is laterally present in the precloacal region in front of the spicules. The tail is filliform and the annulations
0.67–1 µm
are more evident on this region.Three caudal glands are visible. The
two juveniles
measured were in third and fourth stage. The morphological differences between juveniles were not seen
Female
The females are very similar to males, although some minor morphological differences can be observed. There is no apparent sexual dimorphism. The specimens size ranges from
1524 µm
to
1762 µm
. The size of cephalic setae varied from
3.5–5 µm
and the subcephalic setae from
3–5 µm
. The somatic setae are shorter
2.5–3.5 µm
. The nerve ring occupies 52–67 % of the total pharynx length. The specimens possess two opposed and reflexed ovaries. The vulva occupies 37.5–42 % of the total body length.
Discussion
The new species closely resemble
Spirinia septentrionalis
described by
Gerlach (1957)
and
Pastor de Ward (1988)
. However, the species was first described by
Cobb (1914)
and also by
Wieser (1954)
. The geographic distribution of
S. septentrionalis
comprise:
Antartida
,
Chile
,
Brazil
, Hawaii and
Argentina
. The main morpholmetrical differences are shown in table 4.
The species described by Gerlach, formely known as
S. parasitifera
was only based on
one males
morphological features. Despite some morphological similarities, the new species has different features such as subcephalic setae, somatic setae all over the body and number and position of the teeth.
Although the reproductive system of specimens described by Pastor de Ward was similar to the new Brazilian species, the glands present in the two portions of the vulva were not seen.
The
S. septentrionalis
described by Wieser does not have subcephalic setae, but has somatic setae on the cervical region. The presence of the two dorsal teeth and one very small subventral tooth were observed in the new species, however, the specimen described by Wieser only had one dorsal tooth that was barely visible.
FIGURE 3.
Spirinia elongata
sp. n.
A: Total body; B: Head region; C: Tail region; D: Pharyngeal region; E: Copulatory apparatus.
FIGURE 4.
Spirinia elongata
sp. n.
A: Total body; B: Head region; C: Pharyngeal region; D: Vulva region.
The subscephalic setae has a similar number of
Spirinia gerlachi
(Luc and De Coninck, 1959)
Gerlach, 1963
and
Spirinia schneideri
(Villot, 1875)
Gerlach, 1963
but both species are distinguished from
S. elongata
by the number and position of the teeth.
FIGURE 5.
Spirinia elongata
sp. n.
a: Total body; b: Pharyngeal region; c: Spicule; d: Amphids; e: Tail region; f: buccal cavity with three teeth (two dorsal and one ventral).
Based on morphological features
Spirinia elongata
differs from
Spirinia
species
by the position of three teeth (two dorsal and one ventral).
According to
Vincx and Gourbault (1989)
among the nine valid species only
Spirinia gerlachi
(Luc and De Coninck, 1959)
had one dorsal and two subventral teeth. Although the Brazilian species also has three teeth, they are differently positioned.
S. elongata
morphological features (number of subcephalic setae and presence and position of teeth) are compared with those of the other valid species in table 5.
TABLE 4.
Morphometrical features (mm) of
Spirinia elongata
(sp. nov.) compared to
Spirinia septentrionalis
.
Morphometrical
Spirinia elongata
|
Wieser, |
Gerlach, |
Pastor |
de Cobb, |
features |
1954 |
1957 |
Ward, 1988
|
1914 |
Male |
Maximum |
Minimum |
average |
L |
2079 |
1344 |
1459 |
2.14 |
1.55 |
2.2 |
|
gub |
31.5 |
24 |
26 |
|
|
2.5 |
|
a |
45 |
22 |
30.5 |
40 |
28 |
27 |
|
b |
14 |
10 |
12 |
16.3 |
11.1 |
13.4 |
|
c |
10.5 |
8 |
9 |
15.3 |
8.5 |
14.5 |
|
Female |
L |
1762 |
1531 |
1665 |
1.68 |
|
2.25 |
1.4 |
% V |
42 |
34 |
39 |
|
|
54 46 |
|
a |
32 |
24 |
28 |
28 |
|
12.2 |
50 |
b |
14.5 |
11.5 |
13 |
14 |
|
14.6 |
9.4 |
c |
7 |
5 |
5.5 |
14 |
|
13.6 |
13 |
TABLE 5.
Morphological features of
Spirinia elongata
(sp. nov.) compared with
Spirinia
valid
species (NeMys database—http://intramar.rug.ac.be/taxondata).
Valid Species Subcephalic setae Presence and position od the teeth
Spirinia gerlachi
(Luc & De Coninck, 1959) Not
mentioned 1 dorsal and 1 ou 2 (?)
Gerlach, 1963
subventral teeth
Spirinia gnaigeri
Ott, 1977
2 circles of 8 2 small subventral subcephalic setae
Spirinia granullata
Allgén 1929
Not
mentioned
Not
mentioned
Spirinia flagellata
Vitiello, 1975 Not
mentioned
Not
mentioned
Spirinia hamata
Wieser, 1967 Not
mentioned 3 teeth
Spirinia megamphida
Vincx & Gourbault, 1989
Not
mentioned Without teeth
Spirinia mokii
Coles, 1987
4 cervical setae Without teeth
Spirinia laevioides
Gerlach, 1963
Not
mentioned 1 dorsal tooth
Spirinia papillata
Vincx & Gourbault, 1989
8 cervical setae 1 dorsal and probably 2 ventralsublateral
Spirinia laevis
(Bastian, 1865)
Gerlach, 1963
2 cervical setae 1 dorsal tooth
Spirinia parasitifera
(Bastian, 1865)
Gerlach 1963
Not
mentioned 1 dorsal e 2 subventral
Spirinia schneideri
(Villot, 1875)
Gerlach, 1963
4 subcephalic setae 1 dorsal tooth
Spirinia septentrionalis
(Cobb, 1898) Gerlach, Not
mentioned 1 dorsal tooth
1963
Spirinia tenuicaudata
(Allgén, 1959)
Gerlach, 1963
Not
mentioned
Not
mentioned