Shell small (up to 14 mm high), snow-white, semi-transparent, thin, fragile, sculpture reticulate. Shape fusiform, slender with high spire and short siphonal canal. Protoconch paucispiral, smooth, with about 1.15-1.25 well rounded whorls.
Teleoconch whorls. 4 or 5 in number, convex, shoulder slightly angulate. Suture rather deep. On first teleoconch whorl 14 high and sharp axial ridges with broad interspaces; 14-16 on penultimate whorl, 15-19 on body whorl.
On spire whorls 3 strong, rounded, high spiral ridges with broad interspaces; 6 or 7 on body whorl. 6-10 fine spiral ridges on siphonal canal. Upper spiral ridge on shoulder giving the shell a slightly angulate shape. Fourth spiral ridge at lower suture, partly hidden under the following whorl. Presence of 4 weak and low spiral threads between suture and adapical spiral ridge. Aperture semi-ovate, outer lip broad, rounded. Paratype 12 showing 6 strong knobs inside outer lip. each knob corresponding with interspace: lowest knob on beginning of siphonal canal. Siphonal canal straight, open, short. Aperture and siphonal canal about 1/2 of total shell length. Columella curved, smooth, formed by resorption of sculpture and outer shell layer.
Periostracum thick, yellowish or dark brown, copying sculpture, consequently having a reticulate appearance. Each intersection between spiral and axial sculpture ornamented with short hair, resulting in a hirsute appearance. Hairs on adapical spiral cord often bicuspid.
Operculum corneus, pale yellowish-brown, oval with terminal nucleus.
Radula typically buccinid. Central tooth tricuspid, the central cusp slightly larger. Lateral teeth tricuspid, with broad base, outer cusp largest, inner cusp smallest.

Pararetifusus (=Eclectofusus) dedonderi n.sp. is characterized by a high spire and a strong, reticulate sculpture in combination with a small, smooth, paucispiral protoconch and a reticulate and hirsute periostracum. Pararetifusus tenuis (Okutani, 1966) resembles P. dedonderi much in spiral sculpture, protoconch and radula. The lateral teeth have equally sized cusps in P. tenuis, while their size is variable in P. dedonderi. The shell of P. tenuis differs by the absence of axial sculpture, by a lesser number of teleoconch whorls (3 or 4 instead of 4 or 5), and by a thin and smooth periostracum.
Americominella duartei Klappenbach & Ureta, 1972 exhibits a remarkable resemblance with P. dedonderi. Sculpture and periostracum are virtually the same. The radula is quite identical with the exception of the central tooth which has a concave base in A. duartei (instead of rectangular) and the broader base of the lateral teeth. A. duartei differs at once in having a broad, depressed protoconch consisting of 1.50 whorls, and differs considerably in range (subantarctic, off Argentina) and size (up to 90 mm). Some species belonging to Muricidae. Ranellidae and Turridae can look similar to P. dedonderi but have a different radular morphology.