Campylaimus gerlachi Timm, 1961

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 gerlachi Timm, 1961

Materials

Type status: Other material. Occurrence: catalogNumber: SMNH-177084 ; individualCount: 3; sex: 2 females, 1 male; Location: waterBody: Baltic; country: Sweden; maximumDepthInMeters: 0.02; verbatimLatitude: 58°46,00'N; verbatimLongitude: 17°49,52'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 5; day: 26; habitat: Soft sediment Type status: Other material. Occurrence: catalogNumber: SMNH-177085 ; 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-177086 ; individualCount: 2; sex: 1 female, 1 juvenile; Location: waterBody: Baltic; country: Sweden; locality: Oeregrund ; minimumDepthInMeters: 38; maximumDepthInMeters: 38; verbatimLatitude: 60°24,21'N; verbatimLongitude: 18°29,10'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 5; day: 19; habitat: Soft mud with clay Type status: Other material. Occurrence: catalogNumber: SMNH-177087 ; individualCount: 2; sex: female; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 45; maximumDepthInMeters: 55; verbatimLatitude: 58°17,32'N; verbatimLongitude: 11°11,24'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 9; habitat: Coarse sediment with algae Type status: Other material. Occurrence: catalogNumber: SMNH-177088 ; individualCount: 2; sex: male; Location: waterBody: Skagerrak; country: Sweden; locality: Bratten ; minimumDepthInMeters: 30; maximumDepthInMeters: 70; verbatimLatitude: 58°22,14'N; verbatimLongitude: 11°05,00'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 8; day: 9; habitat: Gravel, mud, algae Type status: Other material. Occurrence: catalogNumber: SMNH-177089 ; individualCount: 1; sex: female; Location: waterBody: Baltic; country: Sweden; maximumDepthInMeters: 0.02; verbatimLatitude: 58°46,00'N; verbatimLongitude: 17°49,52'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 5; day: 26; habitat: Soft sediment Type status: Other material. Occurrence: catalogNumber: SMNH-177090 ; 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-177092 ; 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-177098 ; 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-177109 ; individualCount: 1; sex: 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-177112 ; individualCount: 1; sex: female; 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-177121 ; individualCount: 1; sex: female; Location: waterBody: Baltic; country: Sweden; locality: Hoega Kusten ; minimumDepthInMeters: 86; maximumDepthInMeters: 86; verbatimLatitude: 62°49,10'N; verbatimLongitude: 18°23,44'E; Identification: identifiedBy: O. Holovachov; dateIdentified: 2018; Event: year: 2011; month: 5; day: 23; habitat: Silty mud on rather stiff clay Type status: Other material. Occurrence: catalogNumber: SMNH-177125 ; 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 TYPE-9205 (same slide as C.triclados) ; 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: Other material. Occurrence: catalogNumber: SMNH TYPE-9207 (same slide as C.triclados) ; 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

Description

Measurements. Table 1 . Adult. Figs 1 , 2, 3. Cuticle without longitudinal striation. Space between dorsal and ventral limbs of amphid not developed ( Fig. 2 a). Lateral alae narrow, appearing externally as two straight lines encompassing entire length of amphid. It originates at level with anterior edge of amphid, extends posteriorly as two lines parallel and very close to ventral limb of the amphid ( Fig. 2 b) and ends at level of posterior fifth of tail by merging with posterior end of ventral limb of amphid ( Fig. 3 c, d). Secretory-excretory pore opens posterior to cardia, at level with anterior part of intestine ( Fig. 2 d). Tail with clavate terminal part. Male. Anteriormost edge of amphid positioned just posterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 2.2-2.7 labial region diameters in length. Ventral limb of amphid extends along entire body to posterior fifth of tail. Ventral limb of amphid is 1.0-1.5 wider than dorsal limb. Spicules with rounded manubrium and subcylindrical, arcuate shaft ( Fig. 3 a). Gubernaculum with dorsal apophysis ( Fig. 3 b). Precloacal supplements/sensilla invisible in current specimens. Two pairs of ventrosublateral setae located along posterior half of tail and one pair of sublateral setae located subterminally. Female. Anteriormost edge of amphid positioned just posterior to oral opening. Dorsal limb of amphid extends for a short distance posteriorly, equal to 2.1-2.3 labial region diameters in length. Ventral limb of amphid extends along entire body to posterior fifth of tail. Ventral limb of amphid is 1.5 wider than dorsal limb. Vagina straight ( Fig. 2 e, f). One pair of ventrosublateral setae located along middle of tail and one pair of sublateral setae located subterminally.

Diagnosis

Body 0.34-0.52 mm long; cuticle without longitudinal striation; anteriormost edge of amphid just posterior to oral opening; dorsal limb of amphid equal to 2.2-2.7 labial region diameters in male, 2.1-2.3 labial region diameters in female; ventral limb of amphid extends towards posterior fifth of tail in both female and male; ventral limb of amphid is 1.0-1.5 wider than dorsal limb; interamphideal space absent; secretory-excretory pore opens posterior to cardia; spicules 14-22 µm long; precloacal supplements indistinct; tail equal to 4.7-8.9 anal body diameters in length, with clavate terminal part.

Taxon discussion

Originally described as C. inaequalis by Gerlach (1950) and subsequently renamed into C. gerlachi by Timm (1961), the species was described from the Kiel Bay ( Gerlach 1950), the Bay of Bengal ( Timm 1961) and from the Yellow Sea ( Huang and Zhang 2006), not accounting for published records from other parts of the world which were not accompanied by the proper species descriptions. Recent specimens and populations described by Gerlach (1950), Huang and Zhang (2006), Timm (1961) are united by a combination of the following characters: body less than 0.7 mm long, dorsal limb of the amphid equal to 2-3 labial region diameters in length, ventral limb of the amphid extends towards the posterior part of the tail, but does not reach the tail tip, both limbs of roughly equal width and the tail terminus clavate in shape. Villares et al. (2013) found a single male from Argentina with two precloacal supplements, which they also described under the name C. gerlachi. Unfortunately, since the description of this specimen does not cover all diagnostic features, it is impossible to verify the taxonomic position of the specimen and compare it to the population of C. gerlachi found in Sweden.

Figures

Figure 1. Campylaimus gerlachi Timm, 1961 (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.