Molgolaimus haakonmosbiensis

Molgolaimus haakonmosbiensis Portnova, 2009

Languages: English

Overview

General Description

The body is short and cylindrical. The cuticle is finely striated, with the striation especially visible on the tail. The cuticle thickens at the head. The head is small and wide, and is separated from the body by a small narrowing before the head setae. The inner and outer labial sensilla are indistinct.

There are four cephalic setae each 3–4 µm long, arranged slightly over the cephalic constriction. The amphidial fovea is circular, and is distinctly sclerotized, measuring 5–6 µm in diameter (45–50 % of the corresponding body diameter). The distance from the apex to the anterior border of the amphidial fovea is 10–11 µm, identical for males and females. There are no somatic setae along the body.

The stoma is small and very narrow, weakly sclerotized, and is without teeth. The oesophagus is narrow, cylindrical, and muscular along its entire length, posteriorly forming a pronounced spherical bulb. The diameter of the bulb is 20 µm. The cardia is small and extended.

The glandular body of the renetta cell is porrect, and lies below the cardia at the ventral side of the body. The excretory pore is located between the nervous ring and the bulb.

The male reproductive system is monorchic. There is outstretched testis situated to the left of the intestine. The vas deferens is long and thin. The spermatozoa are oval and trapezium-shape, and are very dense, filling the testes.

The spicules are short, thin, flexuous, and are ventrally bent. They have dilated and excurved proximal parts. The length of spicules are 30.5 µm (arch), and 24.4 µm (chord). The relation of the spicules length vs. the anal body diameter is 1.32–1.45.

The gubernaculum has a thin, long, claw–like, hamose front apophysis. The length of the apophysis is 12.2 µm. The two precloacal papilla form supplements with short terminal setae and are present in all males. The distance between the anus and the nearest supplement is 12.2 µm. The distance between the two supplements is 6.1 µm.

The female reproductive system is didelphic, with reflexed ovaries. The anterior ovary is slightly longer than the posterior one. The ovaries are located to the left of the intestine.

The tail is conical and evenly tapering. The relation of the spicules length vs. anal body diameter . is 2–2.9. The relation of body length vs. the spicules length is 17.5–20. The relation of the tail length vs. the spicules length/anal body diameter is 42.2–46.3. A row of somatic setae 1–2 µm long are present at the ventral side of the tail.

(Portonova, 2009)

 

Author(s): Allen, Chris
Rights holder(s): Allen, Chris

Ecology and Distribution

Distribution

Haakon Mosby Mud Volcano, Norwegian Sea at 1,288m (Portonova, 2009).

Author(s): Allen, Chris
Rights holder(s): Allen, Chris

References

Portonova, D. (2009).  Free-living nematodes from the deep-sea Håkon Mosby Mud Volcano, including the description of two new and three known species. Zootaxa. 2096, 197–213.