Rev: 01/03/2024
Oncholaimus oxyuris Ditlevsen, 1911
Synonyms:
Females:
Males:
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Probably omnivore-predators with large stoma and sharp teeth (Heip et al., 1985; Tchesunov, 2015). Considered a dominant predatory brackish-water nematode . When prey become scarce, cannibalism occurs; large males may attack up to five, smaller individuals of the same species in half an hour uwhen other prey are not available (Smol et al., 1980)
Completes three life cylcles in two years in a brackish water pool in Belgium, one generation per year at mean temperatures below 11.2 C and two generations at mean temperatures above 13.9C (Smol et al., 1980).
Females of O. oxyuris produce a maximum of 37 eggs. The species is relatively large, has slow development and long generation time; it is considered a K-selected species (Smol et al., 1980)
The following observations on sexual processes were made for Oncholaimus oxyuris. They may differ in other species.
The Demanian system features in "traumatic insemination" in which the male uses spicules and secretions to puncture the cuticle of the posterior of the female to form a copulatory pore. Sperm are released into the pore. The sperm injected into the female move through terminal ducts and reach the main duct of the Demanian system. The sperm move forward in the main duct to the uterus through the uvette and ductus uterinus. Eggs are fetrilized in the uterus. After withdrawal of the spicules a "wound plug" seals the pore (Coomans et al., 1988; Tchesunov, 2015).
Ecophysiological Parameters:
Coomans, A., Verschuren, D., Vanderhaeghen, R. 1988. The demanian system, traumatic insemination and reproductive strategy in Oncholaimus oxyuris Ditlevsen (Nematoda, Oncholaimina). Zool Scr 17:15-23.
Heip, C., Vincx, M., Vranken, G. 1985. The ecology of marine nematodes. Oceanography and marine biology. Ann Rev Lond 23:399-489
Smol, N., Heip, C.H.R., Govaert, M. 1980. The life cycle of Oncholaimus oxyuris (Nematoda) in its habitat. Ann. Soc. Roy. Zool. Belg. 110:87-103