Draconema brasiliensis and Draconema fluminensis (Chromadorida, Draconematidae): two new species of free living nematodes from a rocky shore affected by upwelling on the Brazilian coast
Author
Venekey, Virág
Laboratório de Meiofauna, Depto. de Zoologia, Universidade Federal de Pernambuco Av. Prof. Nelson Chaves, s / n; CEP: 50739 - 000; Cidade Universitária, Recife-PE, Brasil. e-mail: virag _ venekey @ yahoo. com. br
Author
Lage, Luciana Monteiro
Author
Genevois, Verônica Da Fonsêca-
text
Zootaxa
2005
2005-12-02
1090
1
51
64
https://biotaxa.org/Zootaxa/article/view/zootaxa.1090.1.3
journal article
10.11646/zootaxa.1090.1.3
11755334
5051027
44FD5824-29C7-400E-9EF2-DF3CC7485B05
Draconema brasiliensis
sp.n.
(
Figs 2A–F
,
3A–E
)
Holotype
: male, slide
UGMD
104087 in
RUG
.
Allotype
: female, slide
UGMD
104088 in
RUG
.
Paratypes
:
6 males
, slides 01–07NM and
7 females
, slides 08–14NM in
LMZOO UFPE
.
Type locality: Pedra Vermelha, Cabo Frio Island, Arraial do CaboRJ,
Brazil
.
Habitat: marine intertidal phytal environment on granite rocky shore formation
Etymology: named after
Brazil
, country of sampling.
Measurements:
Holotype
male:
L=
1452 µm
; CAT=12; t=
127 µm
; CATat=
25 µm
; CATpt=
27 µm
; ABD=
47 µm
; tmr=
42 µm
; Ph=
153 µm
; Wapr=
3 µm
; SlAT1=
55 µm
; SvAT1=
49 µm
; SlATL=
48 µm
; SvATL=
34 µm
; spic=
84 µm
; gub=
41 µm
; b=9,5; c=11,4.
Allotype
female:
L=
1299 µm
; CAT=12; t=
115 µm
; CATat=
21 µm
; CATpt=
26 µm
; ABD=
31 µm
; tmr=
49 µm
; Ph=
153 µm
; Wapr=
3 µm
, SlAT1=
54 µm
; SvAT1=
47 µm
; SlATL=
45 µm
; SvATL=
32 µm
;
V
%=54; b=8,5; c=11,3.
Paratype
males (n=7):
L=
1236
–
1401 µm
; CAT=12; t=
127
–
140 µm
; CATat=
22
–
26 µm
; CATpt=
27
–
31 µm
; ABD=
41
–
47 µm
; tmr=
42
–
48 µm
; Ph=
115
–
166 µm
; Wapr=
3 µm
; SlAT1=
55
–
66 µm
; SvAT1=
39
–
59 µm
; SlATL=
45
–
52 µm
; SvATL=
32
–
37 µm
; spic=
77
–
97 µm
; gub=
34
–
44 µm
; b=7,5
–
11,3; c=8,8
–
10,2.
Paratype
females (n=7):
L=
1070
–
1465 µm
; CAT=12; t=
102
–
127 µm
; CATat=
20
–
28 µm
; CATpt=
23
–
32 µm
; ABD=
31
–
38 µm
; tmr=
39
–
55 µm
; Ph=
115
–
178 µm
; Wapr=
3 µm
, SlAT1=
52
–
58 µm
; SvAT1=
43
–
50 µm
; SlATL=
36
–
49 µm
; SvATL=
31
–
34 µm
;
V
%=49
–
56; b=8,0
–
10,1; c=9,3
–
14,4.
Description
Males
Body small and typically shaped as in other
Draconema
specie
s
with swollen pharyngeal region (
Fig 2A
). The first 15–16 postrostral annules are prominently enlarged and present subcuticular markings. Cuticle with annulations extending from the nonannulated cephalic region (helmet) to the caudal region where the nonannulated portion presents minute punctuations. Somatic setae with variable lengths present along the body arranged in 8 longitudinal rows, 2 subdorsal, 4 sublateral and 2 subventral.
Swollen pharyngeal region 9–13% of total body length (relation between length and width: 2,0) (
Fig 2B
). Amphids large, loopshaped with the ventral arm often longer than the dorsal arm, positioned slightly dorsal on the nonannulated part of the helmet.
Six lips can be visualized at the anterior portion of the helmet. Each lip has one associated sensory setae 8.6–9.9 m long. Helmet length varying from
32 to 36 m
long.
Twelve cephalic adhesion tubes (CAT), paired and in two transverse rows on the dorsal side of the helmet. Anteriorly positioned CAT shorter than those more posteriorly. In
holotype
the pair most anterior has
25 m
long while the most posterior has
27 m
long. Subcephalic setae also present in different positions of helmet.
The buccal cavity is minute and without teeth. Pharynx with swollen anterior corpus and posterior bulb (dumbbellshaped) separated by a constricted region encircled by the nerve ring (posterior bulb longer than anterior corpus). Pharyngeal glands present, with indistinguishable opening. Intestine larger anteriorly, becoming narrow posteriorly and having differentiated rectum. Secretoryexcretory gland not observed.
FIGURE 2.
Male holotype of
Draconema brasiliensis
sp.n.
— A. Whole body, B. Pharyngeal region, C. Cloacal region with copulatory apparatus, D. Posterior body region, E. Posterior adhesion tubes, F. Nonannulated punctuated tail region.
FIGURE 3.
Female allotype of
Draconema brasiliensis
sp.n.
— A. Whole body, B. Pharyngeal region, C. Midbody region with reproductive system, D. Vulva region, E. Posterior adhesion tubes.
All posterior adhesion tubes anteriorly to cloaca (
Fig 2D
–
2E
), 9 sublateral and 15
–
17 subventral PATs at each side of the body. Both PATs become shorter from anterior to posterior part of the body. The sublateral PATs are always longer than the equivalent positioned subventral ones (i.e. first sublateral PAT
55 m
long, first subventral PAT
49 m
long in
holotype
).
The reproduction system is composed by one outstretched testis directed anteriorly and situated at the left side of intestine. Cephalated spicules, equals in size and shape, varying from
77 to 97 m
long (1.8–2.0 in relation to ABD) (
Fig 2C–2D
). Gubernaculum
34–44 m
long, corpus parallel to the spicules and with a reduced lateral wing. Four pairs of anal setae, 2 subventral and 2 sublateral,
11–16 m
long. Two are anterior and two are posterior to the anus.
Tail 2,5 anal diameters long in
holotype
(in
paratypes
is 2.7–3.4). Nonannulated part of the tail 30–37% of tail length. Six pairs of setae on the nonannulated punctuated tail region (
Fig 2F
), position measured from last complete tail annule to tail tip: 3 subdorsal pairs; 1 long pair just posterior to last complete tail annule (
42–51 m
long), 1 short pair just posterior to long pair and 1 short pair about 33%; 2 subventral pairs, 1 short pair about 50% and 1 short pair about 60%; 1 lateral short pair about 75%. Caudal glands are extended to the precaudal region.
Females
Similar to males in most morphological aspects (
Fig 3A
). The amphids are conspicuously inverted “U” shaped. Swollen pharyngeal region 10–13% of total body length (
Fig 3B
). Helmet length
32 to 39 m
long. Reproductive system didelphicamphidelphic with antidromoudly reflexed ovaries, positioned at the left side of the intestine (
Fig 3C
). Vulva, a transverse slit and protruded, lying between 49–56% of body length (
Fig 3D
). Two pairs of paravulvar setae, 1 anterior and 1 posterior to the vulva (anterior 7.5–
11 m
and posterior 8.5–
11 m
long). Vagina sclerotized. All PATs between the vulva and anus, intermingled with somatic setae (
Fig 3E
). One row of 14 sublateral and one of 17–19 subventral adhesion tubes at each side of the body. Anal body diameter smaller than in males,
31–
38 m
. Position and number of setae on nonannulated tail region as in males. The length of the long pair just posterior to last complete tail annule varies from
42 to
49 m
. Caudal glands extending anteriorly to the anus as in males.