Campylaimus orientalis Fadeeva, Mordukhovich & Zograf, 2016

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 orientalis Fadeeva, Mordukhovich & Zograf, 2016

Materials

Type status: Other material. Occurrence: catalogNumber: SMNH-177075 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 40; maximumDepthInMeters: 50; verbatimLatitude: 58°15,40'N; verbatimLongitude: 11°27,46'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2010; month: 8; day: 21; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177078 ; individualCount: 2; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 25; maximumDepthInMeters: 50; verbatimLatitude: 58°22,20'N; verbatimLongitude: 11°09,26'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 9; habitat: Muddy sand Type status: Other material. Occurrence: catalogNumber: SMNH-177079 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Kristineberg-Lysekil ; minimumDepthInMeters: 53; maximumDepthInMeters: 53; verbatimLatitude: 58°15,73'N; verbatimLongitude: 11°26,10'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2014; month: 8; day: 14; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177080 ; individualCount: 3; sex: 1 female, 2 males; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 20; maximumDepthInMeters: 30; verbatimLatitude: 58°16,04'N; verbatimLongitude: 11°27,34'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2010; month: 8; day: 21; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177081 ; individualCount: 2; sex: 1 female, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Kristineberg-Lysekil ; minimumDepthInMeters: 53; maximumDepthInMeters: 53; verbatimLatitude: 58°15,73'N; verbatimLongitude: 11°26,10'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2014; month: 8; day: 14; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177082 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 40; maximumDepthInMeters: 50; verbatimLatitude: 58°15,40'N; verbatimLongitude: 11°27,46'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2010; month: 8; day: 21; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177083 ; individualCount: 1; sex: female; 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-177093 ; individualCount: 4; sex: 3 females, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Kristineberg-Lysekil ; minimumDepthInMeters: 53; maximumDepthInMeters: 53; verbatimLatitude: 58°15,73'N; verbatimLongitude: 11°26,10'E; Identification: identifiedBy: Oleksandr Holovachov; dateIdentified: 2018; Event: year: 2014; month: 8; day: 14; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177097 ; individualCount: 7; sex: 2 females, 5 males; 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-177099 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 8; maximumDepthInMeters: 15; verbatimLatitude: 58°15,09'N; verbatimLongitude: 11°27,54'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 11; habitat: Muddy sand Type status: Other material. Occurrence: catalogNumber: SMNH-177100 ; individualCount: 2; sex: 1 female, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 53; maximumDepthInMeters: 53; verbatimLatitude: 58°20,06'N; verbatimLongitude: 11°09,24'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 9 Type status: Other material. Occurrence: catalogNumber: SMNH-177101 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 25; maximumDepthInMeters: 50; verbatimLatitude: 58°22,20'N; verbatimLongitude: 11°09,26'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 9; habitat: Muddy sand Type status: Other material. Occurrence: catalogNumber: SMNH-177114 ; individualCount: 3; sex: 1 female, 2 males; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Kristineberg-Lysekil ; minimumDepthInMeters: 53; maximumDepthInMeters: 53; verbatimLatitude: 58°15,73'N; verbatimLongitude: 11°26,10'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2014; month: 8; day: 14; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177117 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Klubban ; verbatimLatitude: 58°15,03'N; verbatimLongitude: 11°27,54'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2014; month: 8; day: 14; habitat: Shells, gravel, sand, mud Type status: Other material. Occurrence: catalogNumber: SMNH-177118 ; individualCount: 2; sex: 1 female, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, near Fiskebaeckskil ; minimumDepthInMeters: 44; maximumDepthInMeters: 44; verbatimLatitude: 58°15,63'N; verbatimLongitude: 11°27,72'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 11; habitat: Soft mud Type status: Other material. Occurrence: catalogNumber: SMNH-177119 ; individualCount: 2; sex: 1 female, 1 male; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Kristineberg-Lysekil ; minimumDepthInMeters: 53; maximumDepthInMeters: 53; verbatimLatitude: 58°15,73'N; verbatimLongitude: 11°26,10'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2014; month: 8; day: 14; habitat: Mud Type status: Other material. Occurrence: catalogNumber: SMNH-177120 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord ; minimumDepthInMeters: 54; maximumDepthInMeters: 54; verbatimLatitude: 58°16,00'N; verbatimLongitude: 11°28,00'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 1976; month: 4; day: 12; habitat: Very fine sediment Type status: Other material. Occurrence: catalogNumber: SMNH-177122 ; 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: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 11; habitat: Soft mud Type status: Other material. Occurrence: catalogNumber: SMNH TYPE-9205 (same slide as C.triclados) ; individualCount: 2; sex: female; 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 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 15 , 16, 17. 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. Space between dorsal and ventral limbs of amphid developed. Lateral alae narrow, appearing externally as smooth uniform band with straight margins. It originates at posterior end of dorsal limb of amphid and ends in a small expansion at basis of tail tip ( Fig. 17 f). Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine. Tail with conoid, gradually narrowing terminal part. Male. Anteriormost edge of amphid positioned anterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 1.9-2.3 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of anterior third of pharynx; 1.2-1.4 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. Gubernaculum plate-like, without apophysis. One small precloacal papilliform sensillum located on 6th annule anterior to cloacal opening ( Fig. 17 c, d). Second precloacal pore-like sensillum located on 10 th– 11th annule anterior to cloacal opening ( Fig. 17 c, d). 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 1.6-2.3 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of anterior third of pharynx; 1.2-1.4 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. Vagina straight. Vulva a transverse slit. One pair of ventrosublateral setae located along posterior third of tail and one pair of dorsosublateral setae located subterminally.

Diagnosis

Body 0.58-0.65 mm long; cuticle without longitudinal striation; anteriormost edge of amphid anterior to oral opening; dorsal limb of amphid equal to 1.9-2.3 labial region diameters in male, 1.6-2.3 labial region diameters in female; ventral limb of amphid extends towards anterior third of pharynx in both sexes, 1.2-1.4 times the length of dorsal limb in both sexes; 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 23-27 µm long; two precloacal supplements; tail equal to 3.9-5.3 anal body diameters in length, with conoid terminal part.

Taxon discussion

The main distinguishing feature of C. orientalis is the shape of the amphid, where the ventral limb is only slightly longer than the dorsal limb and the inter-amphideal space is equal in width to either of the limbs of the amphid ( Fadeeva et al. 2016). This feature unites both type population from the Sea of Japan and recently collected specimens from the Skagerrak, with recent specimens only being somewhat smaller in size (0.58-0.65 mm vs. 0.61-0.85 mm in type specimens), which also proportionally affects a number of other characters.

Figures

Figure 15. Campylaimus orientalis Fadeeva, Mordukhovich & Zograf, 2016 (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.