Draconema brasiliensis, Venekey & Lage & Genevois, 2005

Venekey, Virág, Lage, Luciana Monteiro & Genevois, Verônica Da Fonsêca-, 2005, 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, Zootaxa 1090 (1), pp. 51-64 : 54-58

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.

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.

Figures

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.