Campylaimus rimatus Vitiello, 1974

Holovachov, Oleksandr, 2019, New and known species of the genus Campylaimus Cobb, 1920 (Nematoda: Araeolaimida: Diplopeltidae) from North European marine habitats, Biodiversity Data Journal 7, pp. 46545-46545 : 46545

Campylaimus rimatus Vitiello, 1974

Materials

Type status: Other material. Occurrence: catalogNumber: SMNH-177072 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 352; maximumDepthInMeters: 374; verbatimLatitude: 58°19,18'N; verbatimLongitude: 10°29,34'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 10; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177073 ; individualCount: 1; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 232; maximumDepthInMeters: 240; verbatimLatitude: 58°27,40'N; verbatimLongitude: 10°33,56'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 12; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177074 ; individualCount: 2; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 139; maximumDepthInMeters: 153; verbatimLatitude: 58°34,19'N; verbatimLongitude: 10°38,20'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 12; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177095 ; individualCount: 1; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 390; maximumDepthInMeters: 428; verbatimLatitude: 58°22,30'N; verbatimLongitude: 10°20,33'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 10; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177097 ; individualCount: 1; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 30; maximumDepthInMeters: 39; verbatimLatitude: 58°15,13'N; verbatimLongitude: 11°27,31'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2010; month: 8; day: 21; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177102 ; individualCount: 2; sex: 1 female, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 180; maximumDepthInMeters: 216; verbatimLatitude: 58°28,16'N; verbatimLongitude: 10°37,04'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 11; habitat: Hard bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177104 ; individualCount: 3; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 232; maximumDepthInMeters: 240; verbatimLatitude: 58°27,40'N; verbatimLongitude: 10°33,56'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 12; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177105 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 248; maximumDepthInMeters: 316; verbatimLatitude: 58°28,22'N; verbatimLongitude: 10°29,39'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 11; habitat: Mixed bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177106 ; individualCount: 2; sex: 1 female, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 390; maximumDepthInMeters: 428; verbatimLatitude: 58°22,30'N; verbatimLongitude: 10°20,33'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 10; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177107 ; individualCount: 3; sex: 2 females, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 351; maximumDepthInMeters: 387; verbatimLatitude: 58°22,19'N; verbatimLongitude: 10°23,50'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 10; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH-177123 ; individualCount: 2; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 221; maximumDepthInMeters: 260; verbatimLatitude: 58°28,30'N; verbatimLongitude: 10°33,22'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 11; habitat: Soft bottom Type status: Other material. Occurrence: catalogNumber: SMNH TYPE-9206 (same slide as C.triclados) ; individualCount: 1; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 30; maximumDepthInMeters: 30; verbatimLatitude: 58°15,25'N; verbatimLongitude: 11°27,30'E; Identification: identifiedBy: Oleksandr Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 11; habitat: Soft mud

Description

Measurements. Table 3 . Adult. Figs 11 , 12, 13, 14. Cuticle without longitudinal striation. Lateral pair of outer labial sensilla distinct in some specimens, located half way between tip of lip region and anterior margin of amphid ( Fig. 12 a). Space between dorsal and ventral limbs of amphid developed. Lateral alae narrow, appearing externally as smooth uniform band with straight margins ( Fig. 13 e), but with distinct subcuticular channel and crenate margins when focused midway ( Fig. 13 f). It originates at posterior end of dorsal limb of amphid and ends in a small expansion at basis of clavate part of tail. Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine ( Fig. 13 c, d). Tail with clavate terminal part. Male. Anteriormost edge of amphid positioned anterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 2.2-2.6 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of midpharynx; 1.9-2.4 times the length of dorsal limb. Ventral limb of amphid is as wide as dorsal limb. Interamphideal space extends along pharyngeal region to same level as ventral limb. Spicules with rounded manubrium and conoid, arcuate shaft; distinct velum. Gubernaculum with weak caudal apophysis, often hard to discern. One small precloacal papilliform sensillum located on 5 th– 6th annule anterior to cloacal opening ( Fig. 14 a, b). Second precloacal pore-like sensillum located on 11th annule anterior to cloacal opening ( Fig. 14 a, b). Two pairs of ventrosublateral setae located along posterior half of tail and one pair of dorsosublateral setae located subterminally. Female. Anteriormost edge of amphid positioned anterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 1.9-2.2 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of midpharynx; 1.6-1.9 times the length of dorsal limb. Ventral limb of amphid is as wide as dorsal limb. Interamphideal space extends along pharyngeal region to same level as ventral limb. Vagina straight. One pair of ventrosublateral setae located along posterior third of tail and one pair of dorsosublateral setae located subterminally.

Diagnosis

Body 0.63-0.73 mm long; cuticle without longitudinal striation; anteriormost edge of amphid anterior to oral opening; dorsal limb of amphid equal to 2.2-2.6 labial region diameters in male, 1.9-2.6 labial region diameters in female; ventral limb of amphid extends towards midpharynx in both sexes, 1.9-2.4 times the length of dorsal limb in male and 1.6-1.9 times the length of dorsal limb in female; ventral limb of amphid is as wide as dorsal limb; interamphideal space extends to same level as ventral limb; secretory-excretory pore opens posterior to cardia; spicules 23-26 µm long; two precloacal supplements; tail equal to 4.1-5.3 anal body diameters in length, with clavate terminal part.

Taxon discussion

Original description of this species is based on one male and two females ( Vitiello 1974), while recent material includes 11 specimens. Both populations are similar in most body measurements and in the morphology of the anterior end: position of the oral opening posterior to the anteriormost edge of the amphid and in the shape of the amphid with developed interamphideal space, ventral limb of the amphid two times the length of the dorsal limb and extending to the level of the middle of the pharynx. Observed differences between two populations are limited to spicule length (31 µm in the holotype male and 23-26 µm in recent specimens).

Figures

Figure 11. Campylaimus rimatus Vitiello, 1974 (scale bars = 20 µm, PIJ = pharyngo-intestinal junction / cardia, EP = secretory-excretory pore): a: female tail; b: female pharyngeal region; c: male pharyngeal region; d: male caudal region.