Croconema torquens ( Gerlach, 1963 ) Verschelde, Gourbault & Vincx, 2006

Abolafia, Joaquín, Ruiz-Cuenca, Alba N., Fernandes, Berenice M. M., Cohen, Simone C. & Cárdenas, Melissa Q., 2015, Description of free-living marine nematodes found in the intestine of fishes from the Brazilian coast, Zootaxa 3948 (3), pp. 549-572 : 561-566

publication ID

https://doi.org/ 10.11646/zootaxa.3948.3.8

publication LSID

lsid:zoobank.org:pub:1B11AA5D-9356-445D-88A7-852F64E68F35

DOI

https://doi.org/10.5281/zenodo.5626033

persistent identifier

https://treatment.plazi.org/id/0395A140-FFCE-FFA7-959C-FBCA3AABFEB4

treatment provided by

Plazi

scientific name

Croconema torquens ( Gerlach, 1963 ) Verschelde, Gourbault & Vincx, 2006
status

 

Croconema torquens ( Gerlach, 1963) Verschelde, Gourbault & Vincx, 2006

( Figs 8–10 View FIGURE 8 View FIGURE 9 View FIGURE 10 )

Material examined. Ten females and ten males were examined from Diapterus rhombeus .

Measurements. See Table 2 View TABLE 2 .

Description. Adults: Body 1.22–1.84 mm long. Cuticle with transverse striations forming well developed annuli, having two morphologies: with the anterior margin dentate in the anterior half of body and with the posterior margin dentate in the posterior half; somatic setae present over whole body. Lateral field only seen with SEM, occupying one third body diameter. Anterior end swollen, forming a cephalic capsule lacking transversal striations and bearing short setae. Lip region with six fused lips carrying short setiform papillae. Amphids with sexual dimorphism, smaller in females and larger in males (see description below). Stoma differentiated into two parts, anterior short and wide bearing small teeth, and posterior longer with reduced lumen and very muscular. Pharynx short, scarcely more than twice body diameter at its base, expanded posteriorly in a bulb slightly longer than wide. Nerve ring not observed clearly. Excretory pore not observed. Cardia poorly developed. Intestine in bad condition.

Female: Body with helical habitus. Amphids reduced, spiral, a quarter of lip region daimeter, located at base of lateral lips. Reproductive system didelphic-amphidelphic; ovaries short and not reflexed; oviducts thin; a small sphincter separates each oviduct and uterus; uteri short and swollen with spermatozoa inside; vagina very reduced. Rectum short, less than one anal body diameter. Tail conoid, slightly ventrad curved and ending in a conoid spinneret.

Male: General morphology similar to female, also with helical habitus. Amphids well developed, elliptical, about half lip region width and occupying more than half of the cephalic capsule length. Spicules sickle-shaped, with rounded manubrium, short calamus and ventrad curved lamina with acute tip. Gubernaculum short, less than half of spicule length. Copulatory and precloacal thorns present. Tail conoid, slightly ventrad curved and ending in a conoid spinneret.

T. latus C. torquens D. pellucida P. breviamphida Diapterus rhombeus Diapterus rhombeus View in CoL Diapterus View in CoL Eucinostomus View in CoL Diapterus rhombeus argenteus rhombeus View in CoL Distribution. Croconema torquens was previously reported by Gerlach (1963, 1964) from the Maldives and the Red Sea. This is its first report from Brazil (see Venekey et al. 2010).

Remarks. This material is similar to that described by Gerlach (1963, 1964) although differing in: anterior vulva position (V= 54–66 vs 86), with longer (72–83 vs 55 µm) and more ventrad curved spicules.

TABLE 2. Measurements οf Trissonchulus latus (Wieser, 1953) Inglis 1961, Croconema torquens (Gerlach, 1963) verschelde, Gοurbault & vincx, 2006, Dorylaimopsis pellucida (Cοbb, 1920) Jensen, 1979 Parodontophora breviamphida (Τimm, 1952) Τimm, 1963. All measurements in μm and in the fοrm ∶ mean ± standard deviatiοn (range), when cοrrespοnds.

Character 10♀♀ 10♂♂ 10♀♀ 10♂♂
Bοdy length 2617.9 ± 269.2 (2211-3041) 2385.1 ± 220.4 (2096-2829) 1581.3 ± 185.3 (1218-1840) 1687.1 ± 94.7 (1526-1803) 1564 1431 1309
a 32.8 ± 3.2 (28.5-40.0) 33.3 ± 2.8 (27.8-38.2) 16.6 ± 2.0 (14.1-20.2) 19.9 ± 2.2 (18.0-23.9) 20.6 32.5 31.2
b 5.4 ± 0.5 (4.8-6.4) 5.2 ± 0.5 (4.6-6.2) 5.7 ± 1.2 (4.4-7.8) 7.1 ± 0.9 (5.4-7.8) 5.8 6.4 6.7
c 35.6 ± 3.6 (29.9-41.1) 33.2 ± 3.1 (28.3-37.2) 16.7 ± 2.1 (12.4-20.7) 13.6 ± 2.0 (11.7-17.6) 11.3 9.7 9.5
c' 1.6 ± 0.1 (1.4-1.8) 1.4 ± 0.2 (1.0-1.6) 2.2 ± 0.4 (1.6-3.0) 2.3 ± 0.3 (1.6-2.7) 4.3 3.5 4.9
v 51.6 ± 2.2 (49-55) - 61.7 ± 5.0 (54-66) - 52 - 49
Lip regiοn (width) 24.9 ± 2.1 (22-27) 23.3 ± 1.8 (22-27) 34.7 ± 6.0 (20-42) 33.2 ± 1.1 (32-34) 12 12 14
Cephalic capsule (width) - - 48.0 ± 3.1 (45-51) 45.0 ± 3.5 (41-47) - - -
Cephalic capsule (high) - - 26.3 ± 8.4 (16-36) 31.0 ± 2.0 (29-33) - - -
Amphid (width) 11.2 ± 1.8 (8-12) 13.3 ± 2.6 (10-15) 8.8 ± 1.1 (8-10) 14.5 ± 1.0 (14-16) 10 12 14
Amphid (length) - - 8.0 ± 0.0 (8) 23.5 ± 1.9 (14-16) 10 10 4
Stοma (length) 57.8 ± 7.7 (44-66) 63.2 ± 3.1 (59-71) 35.9 ± 7.1 (27-52) 34.3 ± 4.6 (29-37) 27 32 28
Stοma (width) 8.7 ± 1.7 (6-10) 9.2 ± 1.8 (7-12) 37.1 ± 10.1 (22-52) 36.7 ± 2.5 (34-39) 5 5 6
Basal bulb 62 (n=1) 32.5 ± 5.9 (25-39) 35.5 ± 12.0 (27-44) 37.7 ± 9.3 (27-44) ? ? ?
Pharynx (length) 415.7 ± 33.9 (360-481) 378.3 ± 41.7 (327-442) 237.6 ± 50.4 (148-298) 197.2 ± 36.0 (175-270) 238 189 ?
Neck (length) 485.6 ± 30.2 (442-538) 457.0 ± 39.3 (410-519) 280.3 ± 54.1 (208-370) 242.2 ± 40.2 (216-323) 270 223 194
Cuticle (width) 3.8 ± 1.5 (2-5) 2.3 ± 0.9 (2-5) 2.3 ± 0.9 (2-5) 2.0 ± 0.0 (2) 2 2 1.5
Bοdy diameter at neck base 74.8 ± 8.8 (59-86) 74.9 ± 5.8 (62-84) 85.5 ± 9.9 (74-103) 79.3 ± 5.9 (69-86) 62 42 33
Bοdy diameter at vulva 80.4 ± 11.2 (62-96) 71.8 ± 5.5 (66-84) 95.4 ± 9.8 (84-118) 85.8 ± 10.6 (71-96) 76 44 42
Anteriοr οvary οr testis (length) 185.0 ± 0.0 (185-185) ? ? 92 (n=1) ? ? 96
Anteriοr uterus (length) 140.0 ± 0.0 (140-140) - ? - ? ? 194
Pοsteriοr οvary οr testis (length) ? ? ? 113.5 ± 27.6 (94-133) ? ? 96
Pοsteriοr uterus (length) 177.0 ± 7.1 (172-182) - ? - ? ? 178
vagina (length) 11.6 ± 6.6 (5-22) - 12.7 ± 3.5 (10-17) - 12 - 7
vulva - anteriοr end 1370.0 ± 89.7 (1205-1500) - 959.9 ± 116.4 (801-1096) - 808 - 640
Rectum (length) 35.4 ± 6.7 (27-45) ? 42.0 ± 7.1 (37-47) ? ? ? 20
Bοdy diameter at anus οr clοaca 45.5 ± 5.9 (39-59) 54.2 ± 9.7 (42-71) 44.5 ± 3.8 (39-49) 55.7 ± 3.3 (52-62) 32 42 28
Τail (length) 72.3 ± 4.8 (66-83) 71.9 ± 4.6 (62-76) 95.4 ± 10.2 (80-116) 125.3 ± 14.5 (100-145) 138 148 138
Spicule (length) - 74.1 ± 7.5 (62-86) - 77.0 ± 3.6 (72-83) - 91 -
Gubernaculum (length) - 37.0 ± 4.5 (30-44) - 33.4 ± 2.9 (30-38) - 47 -
Gubernaculum (apοphysis) - - - - - 17 -

Kingdom

Animalia

Phylum

Nematoda

Class

Adenophorea

Order

Desmodorida

Family

Desmodoridae

Genus

Croconema

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