Campylaimus Cobb, 1920

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 Cobb, 1920

Campylaimus Campylaimus inaequalis Cobb, 1920

Description

Adult. Body cylindrical or fusiform, tapering anteriorly in the pharyngeal region and posteriorly in the tail region, straight or curved, either ventrally or dorsally, upon fixation. Cuticle annulated along the entire body, annules equal in width; annulation starts at a level with the cephalic setae bases and extends towards the tail terminus; annules visually smooth or with fine longitudinal striation as seen under the light microscope. When present, longitudinal striation covers annules over the entire body length. Lateral alae present; anterior end of lateral alae may connect with the amphideal fovea in some species; posterior end extends towards tail terminus, ending at a certain distance from the tail tip. Body pores and epidermal glands absent. Somatic sensilla present. Labial region bluntly rounded, lips fused, tip of the anterior end often with much thicker cuticle. There are no cuticularised plates or other refractive structures around the anterior end. Inner labial sensilla invisible if present. Outer labial sensilla on the apical surface of the labial region. Of the outer labial sensilla, only lateral ones are often clearly visible under the light microscipe, located half way between the tip of the lip region and the anterior margin of the amphid. Cephalic sensilla setiform; their bases located at the base of the labial region, at various levels relative to the anterior edge of the amphid. Subcephalic and cervical sensilla, deirid and ocelli absent. Amphids usually similar in shape and size between sexes, sexual dimorphism, if present, is reflected in the relative length of the amphid or its sections: amphidial fovea an inverted U-shape with its ventral limb as long as or longer than the dorsal limb. Space between the amphidial limbs is variable in size (narrow or wide). Two species with the amphid in a shape of a longitudinal slit, assumed to be formed due to the reduction of the dorsal limb ( Thanh and Gagarin 2011, Thanh et al. 2012). Amphidial glands often large, located at the level with the posterior part of the pharynx. Secretory-excretory system usually present; renette cell located opposite to the anterior part of intestine. Secretory-excretory ampulla present, located at the level of the intestine in the majority of species (if known). Cuticularised secretory-excretory duct very short, opens to the exterior via a pore, located at the level of the anterior part of intestine, except for C. amphidialis , in which it opens to the outside on the labial region. Nerve ring surrounding pharyngo-intestinal junction, just posterior to the muscular pharynx. Buccal cavity small and undifferentiated: cheilostom broad cylndrical, without rhabdia or sclerotisations; gymnostom and stegostom undifferentiated, closed or funnel-shaped, its slender lining continuous with that of the pharynx. Pharyngeal tubes absent. Pharynx uniformly muscular, cylindrical or fusiform, without visible subdivisions, with evenly distributed myofilaments; pharyngeal lumen uniform in thickness along the entire pharynx length; valves absent. Number and arrangement of pharyngeal glands and their orifices unclear. Cardia elongate, glandular. Tail conoid or subcylindrical, in some species with clavate terminal part. Three caudal glands present, their bodies and nuclei are incaudal; they open via a common spinneret.

Female reproductive system didelphic-amphidelphic with equally developed branches, ovaries outstretched. Spermatheca present in some species. Vulva equatorial, transverse (when described). Vagina straight; pars proximalis vaginae encircled by single sphincter muscle; pars refringens vaginae and epiptygmata absent. Tail most commonly with one pair of ventrosublateral setae located along the middle of the tail and one pair of sublateral setae located subterminally. Rectum short.

Male reproductive system diorchic, testes opposed: anterior testis outstretched and posterior testis reflexed. Spicules paired and symmetrical, arcuate, with weakly defined manubrium and subcylindrical shaft. Gubernaculum plate-like, without strongly developed apophysis. Some species with 2-5 precloacal supplements arranged midventrally; ventrosublateral precloacal and postcloacal sensilla absent. Tail most commonly with two pairs of ventrosublateral setae located along the posterior half of the tail and one pair of sublateral setae located subterminally.

Valid species

Campylaimus abnormis Nguyen Vu Thanh & Gagarin, 2011 ( Thanh and Gagarin 2011)

Campylaimus amphidialis Fadeeva, Mordukhovich & Zograf, 2016 ( Fadeeva et al. 2016)

Campylaimus arquatus Villares, Martelli, Lo Russo & Pastor, 2013 ( Villares et al. 2013)

Campylaimus bonariensis Villares, Martelli, Lo Russo & Pastor, 2013 ( Villares et al. 2013)

Campylaimus cylindricus Gerlach, 1956 ( Gerlach 1956)

Campylaimus gerlachi Timm, 1961 ( Gerlach 1950, Timm 1961)

Campylaimus gracilis Nguyen Vu Thanh, Nguyen Thanh Hien & Gagarin, 2012 ( Thanh et al. 2012)

Campylaimus inaequalis Cobb, 1920 ( Cobb 1920)

Campylaimus lefeverei Gerlach, 1956 ( Gerlach 1956)

Campylaimus longispiculus sp. n.

Campylaimus minor Timm, 1961 ( Timm 1961)

Campylaimus minutus Fadeeva, Mordukhovich & Zograf, 2016 ( Fadeeva et al. 2016)

Campylaimus mirus Gerlach, 1950 ( Gerlach 1956)

Campylaimus orientalis Fadeeva, Mordukhovich & Zograf, 2016 ( Fadeeva et al. 2016)

Campylaimus patagonicus Villares, Martelli, Lo Russo & Pastor, 2013 ( Villares et al. 2013)

Campylaimus ponticus Sergeeva, 1981 ( Sergeeva 1981)

Campylaimus pulcher Fadeeva, Mordukhovich & Zograf, 2016 ( Fadeeva et al. 2016)

Campylaimus rimatus Vitiello, 1974 ( Vitiello 1974)

Campylaimus siwaschensis Sergeeva, 1981 ( Sergeeva 1981)

Campylaimus striatus Boucher & Helléouët, 1977 ( Boucher and Helléouët 1977)

Campylaimus tkatchevi Tchesunov, 1978 ( Tchesunov 1978)

Campylaimus triclados sp. n.

Nomen nudum

Campylaimus abditus Bussau, 1993 ( Bussau 1993)