Campylaimus lefeverei Gerlach, 1956

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 lefeverei Gerlach, 1956

Materials

Type status: Other material. Occurrence: catalogNumber: SMNH-177077 ; individualCount: 1; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Gullmarsfjord, Kvarnbukten ; minimumDepthInMeters: 5; maximumDepthInMeters: 5; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2010; month: 8; day: 27

Description

Measurements. Table 2 . Adult. Figs 8 , 10. Cuticle without longitudinal striation. Space between dorsal and ventral limbs of amphid not developed. Lateral alae broad, appearing externally as two crenate lines encompassing entire length of the amphid. It originates at level with anterior edge of amphid, extends posteriorly as two lines parallel to and widely spaced from ventral limb of amphid ( Fig. 10 f) and ends at level of posterior fourth of tail by merging with posterior end of ventral limb of amphid. Interamphideal space absent. Cardia extremely long, more than corresponding body diameter in length. Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine ( Fig. 10 d). Tail with clavate terminal part. Male. Not found. Female. Anteriormost edge of amphid posterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 1.6 labial region diameters in length. Ventral limb of amphid extends along entire body to posterior fourth of tail. Ventral limb of amphid is 3 times wider than dorsal limb. Vagina straight ( Fig. 10 e). Spermatheca absent, spermathozoa in uterus. One pair of ventrosublateral setae located along middle of tail and one pair of dorsosublateral setae located just behind posterior end of the lateral alae.

Diagnosis

Body 0.96 mm long; cuticle without longitudinal striation; anteriormost edge of amphid posterior to oral opening; dorsal limb of amphid equal to 1.6 labial region diameters in female; ventral limb of amphid extends towards posterior fourth of tail; ventral limb of amphid is 3 times wider than dorsal limb; interamphideal space absent; secretory-excretory pore opens posterior to cardia; tail equal to 14.5 anal body diameters in length, with clavate terminal part.

Taxon discussion

Original description of this species is based on two specimens, a male and a female ( Gerlach 1956) while the recent specimen is a female. Both populations are similar in the morphology of the anterior end: position of the oral opening anterior to the anteriormost edge of the amphid and in the shape of the amphid without interamphideal space, with ventral limb of the amphid extending towards tail tip and the dorsal limb of the amphid 1.6-1.7 times the labial region diameter in length. Observed differences between the two populations include much smaller body of the recently collected female (959 µm vs. 1553-1555 µm in the original description) and thus smaller measurements of a number of characters (length of cephalic setae, length of dorsal limb of the amphid etc.). Since inter- and intraspecific variability in species of the genus Campylaimus are currently poorly understood and since no qualitative differences can be found between these two populations, they are considered here to belong to the same species.

Figures

Figure 8. Campylaimus siwaschensis Sergeeva, 1981 (c-d) and C. lefeverei Gerlach, 1956 (a-b) (scale bars = 20 µm, PIJ = pharyngo-intestinal junction / cardia, EP = secretory-excretory pore): a, c: female pharyngeal region; b, d; female tail.