Campylaimus triclados Holovachov, 2019

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 triclados Holovachov, 2019 sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: SMNH TYPE-9205 ; 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 Type status: Paratype. Occurrence: catalogNumber: SMNH TYPE-9207 ; individualCount: 1; 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: Paratype. Occurrence: catalogNumber: SMNH TYPE-9206 ; individualCount: 2; sex: 1 female, 1 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 Type status: Other material. Occurrence: catalogNumber: SMNH-177105 ; individualCount: 1; sex: male; 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 juvenile; 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: 1; sex: 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-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-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

Description

Measurements. Table 4 . Adult. Figs 18 , 19, 20, 21. Cuticle without longitudinal striation. Space between dorsal and ventral limbs of amphid developed. Lateral alae narrow, appearing externally as smooth uniform band with straight margins, but with crenate margins when focused midway. It originates at posterior end of dorsal limb of amphid and gradually disappears at a short distance from the tail tip. Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine ( Fig. 20 c, d). Tail with conoid terminal part. Male. Anteriormost edge of amphid positioned anterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 1.6-2.5 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of anterior part of intestine; 4.3-5.5 times the length of dorsal limb. Ventral limb of amphid is as wide as dorsal limb. Interamphideal space extends along pharyngeal region further than posterior end of dorsal limb but not reaching posterior end of ventral limb. Spicules with rounded manubrium and conoid, arcuate shaft; distinct velum. Gubernaculum platelike, without apophysis. One small precloacal papilliform sensillum located on 5th-6th annule anterior to cloacal opening ( Fig. 21 a). Second precloacal pore-like sensillum located on 9th annule anterior to cloacal opening ( Fig. 21 a). 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 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of midpharynx; 2.2-2.8 times the length of dorsal limb. Ventral limb of amphid is as wide as dorsal limb. Interamphideal space extends along pharyngeal region further than posterior end of the dorsal limb but not reaching posterior end of 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 0.59-0.69 mm long; cuticle without longitudinal striation; anteriormost edge of amphid anterior to oral opening; dorsal limb of amphid equal to 1.6-2.5 labial region diameters in male, 1.9 labial region diameters in female; ventral limb of amphid extends towards anterior part of intestine in male and midpharynx in female, 4.3-5.5 times the length of dorsal limb in male and 2.2-2.8 times the length of dorsal limb in female; ventral limb of amphid is as wide as the dorsal limb; interamphideal space extends further than posterior end of dorsal limb but not reaching posterior end of ventral limb; secretory-excretory pore opens posterior to cardia; spicules 19-24 µm long; two precloacal supplements; tail equal to 4.3-5.6 anal body diameters in length, with conoid terminal part.

Etymology

The specific epithet refers to the three-partite shape of the amphid, with three "branches": strongly developed dorsal and ventral limbs and prominent interamphideal space.

Taxon discussion

This new species can be easily differentiated from all currently known species of the genus Campylaimus by the shape of the amphid, with interamphideal space being longer than the dorsal limb of the amphid, but shorter than the ventral limb of the amphid. In all other known species with developed interamphideal space ( C. rimatus , C. mirus and C. orientalis ), it is usually as long as the ventral limb of the amphid.

Figures

Figure 18. Campylaimus triclados sp. n. (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.