Parasaveljevia uncinoa, Pastor, Catalina, Russo, Virginia Lo & Villares, Gabriela, 2015

Pastor, Catalina, Russo, Virginia Lo & Villares, Gabriela, 2015, Two new species of Parasaveljevia Wieser, 1953 (Thoracostomopsidae, Nematoda) from Argentinean coasts (Chubut, Argentina), Zootaxa 4027 (4), pp. 551-564 : 554-558

Parasaveljevia uncinoa n. sp.

( Fig. 2 ; Fig. 3 (A‒I), Fig. 4 (A‒H); Fig. 7 (C); Table 1

Material examined. Holotype Male, CNP-NEM N° 1115, collected in winter, 13/06/2006 on “Playa Pozo” beach (42º 49’ S and 64º 53’ W), during low tide. This coastal area is characterized by rock outcrops forms easily eroded material as tuffs and siltstones. The specimens were collected from small tuff holes, covered by sediment and bordered with abundant Polysiphonia brodiei (Dillwyn) Sprengel, 1827 . Characteristics of surface sediment layer: mean particle size (Mean particle size, Q2= 0.22; Fine fraction, FF % = 1.11; SO index = 0.65; SK index = 1.50). This species was found together with several specimens of Patagonema iubatum Pastor et al., 2014. Collector: Catalina Pastor.

Paratypes Six males and three females, same data as holotype mounted on slide numbers CNP–NEM N° 1116‒1117; 1119‒1121; 1124‒1127.

Measurements. See Table 1.

Description. Holotype: Male. One dorsal and two ventro-sublateral lips, rounded in lateral view, with at least one incision on each lip. Two inner labial setae (9 µm long) inserted near apex of each lip, six in total. Two cirri rectangular in shape, 10 Μm long, inserted on the outer surface of ventro sublateral lips at the level of insertion of inner labial setae. Outer labial and cephalic setae situated at the anterior end of cephalic capsule. Six outer labial setae, 48 Μm long, and four cephalic setae all of the same length (25 Μm).

Amphidial fovea indistinct. Front end of the head capsule has a visible junction with the oesophagus. Outer labial and cephalic setae (emerge) from small fenestrae, in anterior margin of cephalic capsule. Cervical setae present in two circles of 6 + 2 setae (20 + 6 Μm long). Anterior part of the buccal cavity bowl shaped, covered by three corpulent curved mandibular plates. Two mandibles large, similar in size (ventro-sublateral), with three lines of nine denticles, one small (dorsal), with two lines of six denticles. Both these mandibles have a hook on the lateral edge, directed towards the centre of the mouth. Ventro-sublateral teeth present at level of the mandibular ring and articulated with it ( Fig. 3 E and C; Fig. 2 ). Refringent cuticularization present on posterior 100 µm of pharynx, anterior to the small cardia.

Reproductive system diorchic, testes opposed. Two spicules each 40 Μm long, arcuate, with velum, proximal end with well-developed cephalisation. Gubernaculum tubular, 3 Μm in width with dorso-caudal apophysis (22 Μm long). One tubular-globular supplement (10 Μm long) situated 83 Μm in front of spicules. Three precloacal ( Fig. 4 B, G1) and two postcloacal ( Fig. 4 B, G2) papillae present. Tail 170 Μm long (AD = 3.4), conical to cylindrical toward the distal end with swollen tip. Tip of the tail lacks setae.

Female. Similar to male in general body shape. Lateral mandibles slightly smaller than in males, with only two rows of denticles. Ventro-sublateral and dorsal teeth smaller than in males ( Fig. 3 C). Reproductive system didelphic amphidelphic, ovaries reflexed. Vagina short, not thickened. Tail 155 Μm long (AD = 3.68) without setae. Diagnosis and relationships. Parasaveljevia uncinoa n. sp. is characterized by having a long rectangular cirri, positioned at the level of the inner labial setae; rectangular mandibles with prominent lateral hooks, bearing denticles in three (or two) lines of nine (or six) each and six cephalic setae of the same length, inserted at the anterior end of a small head capsule.

The De Man’s ratios of P. uncinoa n. sp. and P. cirrifera Wieser, 1953 are similar, but the two species differ in the length of the cephalic capsule and shape of the mandibles. Parasaveljevia uncinoa has a greater number of denticles of different sizes on the mandibles, a smaller general body size, and shorter spicules, gubernaculum and tail than P. cirrifera .

Etymology. The specific name refers to the hooks found on lateral ends of mandibles. From the Latin word “uncino”.

Species Parasaveljevia uncinoa n. sp. Parasaveljevia limitensis n. sp.

Male Male Female Male Male Female Juvenile

Holotype Paratypes Paratypes Holotype Paratypes Paratypes

n 1 6 3 1 3 4 1 Total body length 2500 2398.3 (2050-2600) 2166.7 (1910-2470) 2380 2362.5 (2200-2570) 2005 (1770-2510) 950 de Man’s a 41.7 41.2 (37.7-47.3) 32.2 (31.9-32.9) 59.5 63.8 (57.5-80.3) 60.5 (50.3-71.7) 39.6 de Man’s b 4.2 4.4 (4.1-4.6) 4.4 (4.1-4.7) 3.6 3.6 (3.5-3.7) 3.7 (3.6-3.8) 3.2 de Man’s c 14.7 15.7 (15.1-17.3) 13.9 (12.7-14.9) 14.0 14.1 (13.5-15.1) 12.1 (10.9-13.9) 10.0 de Man’s V% ……. …………………………. 57.7 (54.9-59.9) ……… …………………………. 68.3 (54.3-100) ……… Lip-lobe height 7 6.8 (6-7) 8 (7-9) 7 6 (5-7) 5.9 (5-6.5) 4.5 Mandible height 4 5.1 (5-6) 5 7.5 8.4 (7.5-9) 5.6 (4.5-7) 2,0 0 Mandible width 14 14.8 (13-17) 14.8 (12-17.5) 13 12.7 (12-13) 8.1 (7-9.5) 7.5 Dorsal tooth height 3 4.2 (4-6) 10.3 (10-11) 6 5 (4-6) 3.4 (3-3.5) 3 ventrolateral tooth height 10 11.2 (11-13) 4.7 (4-5) 10 10.6 (10-11.5) 8.7 (8-9) 6 Cephalic capsule 10 9.9 (9-10.5) 11 (10-13) 12 10.2 (6-12.5) 6.6 (6-8) 5 Inner Labial setae 9 9.7 (7-12) 12.3 (9-15) 8 6.7 (6-8) 6.7 (5-8.5) 5.5 Outer labial setae (sublateral) 48 44.3 (40-49) 41.7 (38-44) 35 33.5 (32-35) 24.7 (19-32) 50 Cepahlic setae (lateral) 48 44.3 (40-49) 41.7 (38-44) 70 70.5 (67-75) 28.7 (21-35) 25 Cephalic setae (sublateral) 25 26 (25-28) 23.3 (22-25) 32 38 (32-42) 62.7 (60-65) 55 Cervical setae (short) 6 7 (9-5) 3.8 (3-4.5) 12 10.3 (7-12) 9.7 (8-12) Not see Cervical setae (long) 20 14.7 (12-20) 10 (9-11) 16 15.7 (15-17) not seen Not see Buccal cavity depth 15 12.8 (10-15) 11.3 (10-12) 9.5 8.9 (8-9.5) 9.6 (9-10) 4.5 Number of denticles in 3 lines of 3 lines of nine (27) 3 lines of nine (27) 5 lines of 5 lines of 5-10 each 5 lines of 5-10 each not seen ventrosublateral mandible nine (27) 5-10

each

N umber of denticles in in dorsal 2 lines of 2 lines of six (12) 2 lines of six (12) 5 lines of 5 lines of 5-8 each 5 lines of 5-8 each not seen mand ib le six (12) 5-8 each

Anterior to nerve ring 160 151.7 (145-160) 145 (150-150) 160 125 (90-160) 175.7 (120-330) 95 Anterior to cardia 600 548.3 (505-600) 498.3 (465-530) 650 620.0 (460-720) 533.7 (475-660) 295 Anterior to vulva …….. …………………………. 1253.3 (1050-1440) …….. …………………………. 1356.2 (960-1830) ……… Tail length 170 152.5 (145-170) 155.0 (150-165) 170 167.5 (160-170) 166.2 (150-180) 95 Spicule arc length 40 43 (40-45) 31.3 (25-37) 40 38.5 (34-40) …………………………. ……… Cloaca to supplement 83 82.2 (75-90) 52.7 (53-55) 75 67.5 (55-75) …………………………. ……… Supplement length 10 10 (10-10) 67.3 (60-75) 10 9.7 (9-10) …………………………. ……… Apophysis length 22 23.7 (21-28) 42.3 (37-45) 15 13.5 (10-15) …………………………. ……… Head width at cephalic setae 30 28.4 (26-30) 32.2 (31.9-32.9) 20 23.7 (20-26) 18.9 (18-20) 14.5 Body width at cardia 60 52.7 (45-50) 4.4 (4.1-4.6) 53 51.5 (40-58) 55.7 (50-60) 30 Maximum width/at vulva 60 58.3 (50-65) 13.9 (12.7-14.9) 55 70 (55-95) 61.2 (60-65) 40 Width at cloaca/anus 50 43.3 (35-50) 57.7 (54.9-59.9) 40 37.5 (32-40) 33.2 (30-38) 24 Cephalic setae length lat/head width 1.6 1.6 (1.4-1.8) 1.3 (1.2-1.5) 3.5 2.9 (2.8-3.5) 1.5 (1.1-1.8) 1.7 Cephalic setae length sublat/ head w 0.8 0.9 (0.8-1.1) 0.7 (0.7-0.9) 1.6 1.6 (1.5-1.7) 3.3 (3.1-3.6) 3.8 Cloaca to suplement/width at cloaca 1.6 1.9 (1.6-2.6) …………………………. 1.9 1.8 (1.4-2.2) …………………………. ……… Tail length/ width at cloaca/anus (AD 3.4 3.6 (3-4.3) 3.7 (3.3-4.1) 4.2 4.5 (4.2-5.3) 5.1 (4.6-5.3) 4 Spicule length/width at cloaca 0.8 1.1 (0.8-1.1) …………………………. 1.0 1.1 (0.9-1.2) …………………………. ……… cirri length 10 10.2 (10-11) 12 (10-14) 6.0 5.4 (5-6) 5.7 (5-7) 5 Mandible Heigth/Width 0.3 0.3 (0.3-0.4) 0.3 (0.3-0.4) 0.4 0.3 (0.3-0.4) 0.3 (0.2-0.4) 0.3

Figures

FIGURE 2. Figure showing main characters that differ between genera Oxyonchus and Parasaveljevia. A. In apical view of Oxyonchus and Parassaveljevia; B. In cephalic capsule (lateral view); C. In cephalic capsule (ventral view).

FIGURE 3. Parasaveljevia uncinoa n. sp. Line drawings. A. Head in apical view of male paratype; B. Cirri and cephalic setae on anterior end of female paratype; C. Head and buccal cavity of female paratype; D. Cirri and cephalic setae on anterior end of male holotype; E. Head and buccal cavity of male holotype; F. Posterior end of male holotype; G. Posterior end of female paratype; H. Vulva and gonadal apparatus of female paratype; I. Copulatory apparatus, spicule, gubernaculum of male holotype. Scale bar: 1 = 20 µm; 2 = 100 µm.

FIGURE 4. Parasaveljevia uncinoa n. sp. Micrographs of slide mounted specimens. A. Apical view male paratype; B. Cloacal aperture in subventral view of male paratype; C. Apical view male paratype. D. Head and buccal cavity of male holotype; E. Head and buccal cavity of male paratype, sensillae; F. Copulatory apparatus, spicule, gubernaculum of male paratype; G. Cuticularization of pharynx in male holotype; H. Head and buccal cavity of male paratype, ventro-sublateral tooth. Abbrev: VSlat MB = ventro-sublateral mandible; VSlat tooth = ventro-sublateral tooth; D tooth = dorsal tooth; Mb hook = mandible hook, G 1 = precloacal glands; G 2 = postcloacal glands. Scale bar: 1 = 20 µm.

FIGURE 7. Pictorial key to known Parasaveljevia species (with males). A. P. cirrifera, from Wieser, 1953; B. P. limitense n. sp.; C. P. uncinoa n. sp. Scale bar: 1 = 20 µm.