Campylaimus longispiculus 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 longispiculus Holovachov, 2019 sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: SMNH TYPE-9208 ; individualCount: 1; 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: Oleksandr Holovachov; dateIdentified: 2018; Event: year: 2012; month: 10; day: 12; 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-177111 ; individualCount: 1; sex: 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; habitat: Muddy sediment

Description

Measurements. Table 6 . Adult. Figs 22 , 33. Cuticle without longitudinal striation. Space between dorsal and ventral limbs of amphid not developed. Lateral alae narrow, appearing externally as smooth uniform band with straight margins. It originates at posterior end of ventral limb of amphid and fades away along posterior third of tail. Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine. 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 1.8-2.1 labial region diameters in length. Ventral limb of amphid extends along pharyngeal region to level of anterior part of intestine; 2.8-3.5 times the length of dorsal limb. Ventral limb of amphid equal to or slightly wider than dorsal limb. Spicules with rounded manubrium and elongate, arcuate shaft. Gubernaculum without apophysis. One small precloacal papilliform sensillum located on 2nd annule anterior to cloacal opening ( Fig. 33 d). Second precloacal pore-like sensillum located on 7 th– 8th annule anterior to cloacal opening ( Fig. 33 d). These sensilla are less obvious in the holotype. Two pairs of ventrosublateral setae located along posterior half of tail and one pair of dorsosublateral setae located subterminally. Female. Not found.

Diagnosis

Body 0.56-0.65 mm long; cuticle without longitudinal striation; anteriormost edge of amphid anterior to oral opening; dorsal limb of amphid equal to 1.8-2.1 labial region diameters in male; ventral limb of amphid extends towards anterior part of intestine in male, 2.8-3.5 times the length of dorsal limb in male; ventral limb of amphid is as wide as dorsal limb; interamphideal space absent; secretory-excretory pore opens posterior to cardia; spicules 28-35 µm long; two precloacal supplements; tail equal to 4.9-5.3 anal body diameters in length, with clavate terminal part.

Etymology

Specific epithet refers to relatively long spicules in this species.

Taxon discussion

The new species is most similar to C. amphidialis and C. striatus in the size and shape of the amphid, with ventral limb being more than three times as long as the dorsal limb, especially in males. It differs from both C. amphidialis and C. striatus in having relatively shorter ventral limb of the amphid, equal to 2.8-3.5 times the dorsal limb (in male), vs. 8.3-9.5 in C. striatus and 4.6-5.3 in C. amphidialis. It further differs from C. striatus in having smooth annulation of cuticle (vs. with longitudinal striation in C. striatus ) and from C. amphidialis in the position of the excretory pore at the level with the anterior part of intestine (vs. apically on the anterior end in C. amphidialis ) and simple lateral alae along the posterior part of the body (vs. with crenate margins in C. amphidialis ).

Figures

Figure 22. Campylaimus mirus Gerlach, 1950 (a-b) and Campylaimus longispiculus sp. n. (c-d) (scale bars = 20 µm, PIJ = pharyngo-intestinal junction / cardia, EP = secretory-excretory pore): a: female pharyngeal region; b: female tail; c: male pharyngeal region; d: male caudal region.