The shell is moderately small (maximum length 16 mm) and stoutly fusiform. The spire is high, consisting of one and one-half convex nuclear whorls and five or six convex postnuclear whorls. The suture is distinct and weakly impressed. The bodywhorl is of moderate size and fusoid. The aperture is small and ovate to lenticular, with a shallow, moderately broad anal sulcus. The outer apertural lip is thickened, essentially nonerect, and minutely serrate; its inner surface bears six moderately strong denticles. The columellar lip is adherent posteriorly, more or less detached and weakly erect anteriorly. The siphonal canal is moderately short and fused.
The body whorl bears eight prominent axial ridges that may qualify as varices, depending on the definition used. Spiral sculpture consists of 18 prominent spiral cords, three on the shoulder, 12 on the body, and three on the canal, these cords as prominent between the axial ridges as on them. Numerous fine axial lamellae are thrown into scalelike expansions on the spiral cords.
Shell color is uniform orange-brown through red-brown to purple-brown. The aperture is porcelaneous white.

Shell up to approximately 15-18 mm in length (usually smaller in the Mediterranean Sea) with 1.25-1.50 protoconch whorls and up to 5 or 6 rounded teleoconch whorls. Protoconch small with small granules, or rows of small granules. Whorls rounded. Axial sculpture of last teleoconch whorl consisting of 6-11. usually broad, low. rounded ribs. Spiral sculpture of numerous, high, occasionally low, weakly squamous, rounded, similarsized cords.
Aperture small, or moderately large, ovate. Outer lip weakly crenulate, erect, occasionally with weak or strong labial tooth, and with 5-9 weak or strong denticles within. Columellar lip smooth, weakly erect abapically. adherent adapically. Siphonal canal short, sealed.
Light tan, pale or dark brown, occasionally with pinkish protoconch and first teleoconch whorls. Interior of aperture white.

Shell of medium size for the genus, H up to 18 mm, fusiform and solid. Protoconch paucispiral of 1.25-1.5 rounded whorls, globose, apparently smooth but with a microsculpture of small granules often arranged in spiral rows. Teleoconch uniformly pale brown, dark brown, reddish, pinkish or orangeish, occasionally black or white, usually of 6 convex whorls at maturity, slightly elongate and usually rounded, with the last whorl consisting of about 3/4 of total height in adult specimens. Subsutural ramp rounded with impressed suture. Spiral sculpture in the convex part of the whorl consisting of 6 low, weakly squamose and rounded primary cords and approximately equally sized secondary cords. P1 and P2 start in the early teleoconch, IP starts at half of the first teleoconch whorl, while s1, s2 and abis start at half of the second teleconch whorl. Axial sculpture consisting of low, weak, broad, rounded ribs: 9-15 on the first teleoconch whorl; 15-18 on the second whorl; 13-16 on the third whorl; 11-16 on the fourth whorl; 11-15 on the fifth whorl; 9-13 on the last whorl. Outer lip weakly crenulate and with 5 weak to strong internal denticles (some could appear double), occasionally with a labral tooth, formed by the extension of P4. Labral varix slightly nodose, weak, narrow and rounded. Columellar lip moderately expanded ventrally, smooth, adherent adapically and slightly erect abapically. Aperture from narrow to moderately large, elongate-ovate, from pinkish to whitish coloured inside. Siphonal canal short, narrow, straight, ventrally sealed. Animal reddish. Operculum corneous from pale to dark brown, D-shaped/ovate, with subterminal nucleus surrounded by many concentric ridges. Radula typical of Ocenebrinae, with sickle-shaped lateral teeth with a broad base, rachidian bearing short and thick central and lateral cups with a short and thick inner lateral denticle on the base. Marginal area with short denticles and a thick marginal cusp.

There are a few names used to designate different forms, despite the fact that the shell morphology is only slightly variable. These forms were for the most part named by Monterosato, Pallary. and Settepassi. A large number of specimens from both the Atlantic Ocean and the Mediterranean Sea were examined, and no constant difference could be observed in the shell morphology of both populations. The fact that the Mediterranean shell is usually smaller, occasionally broader, and sometimes with a pinkish protoconch and first whorls does not, in my opinion, require the use of a name like O.corallina which is here included in the synonymy. A small or sometimes fairly large labral tooth is occasionally observed in some populations of O. aciculata. The tooth is formed by the extension of the abapical spiral cord of the last whorl. This particular spiral cord is then fairly larger and higher than in "normal” specimens without a labial denticle. This distinctive character is not particular to Mediterranean shells, as I observed the same features in specimens from Brittany (France). Fossil specimens of O. aciculata also have this distinctive character, as well as O. excoelata Cossmann & Peyrot, 1923 from the Miocene of Aquitaine (France). To this date I am not aware of any research to determine the reason of this peculiarity. However, it could be a matter of sexual dimorphism. O. aciculata is a fairly common species.

Shells of this species are easily diagnosed from most of the other Ocinebrina spp. by the rounded primary cords and equally sized secondary spiral cords (Houart 2001), a character shared only with Ocinebrina corallinoides Pallary, 1912 (see below). Similarly to most common and widespread northeastern Atlantic and Mediterranean species, the nomenclatural history of Ocinebrina aciculata is somewhat complicated by a long list of synonyms. Among the synonyms, Murex corallinus Scacchi, 1836 is the only taxon described from within the geographic range of the new species we describe herein (see below) that shows constant, yet subtle morphological differences from O. aciculata. The description of Murex corallinus Scacchi, 1836 was explicitly based on specimens with clean shells not incrusted by sponges (Scacchi 1836) and both the original description (no dark spots on the ribs) and the drawings (similarly sized primary and secondary spiral cords are evident) clearly indicate the typical Ocinebrina aciculata. As no type material of Murex corallinus Scacchi, 1836 (Cretella et al. 2005, N. Maio, pers. comm.) has been found to stabilize this synonymy, we have here designated as neotype a shell of 11.9x6.5 mm from Scacchetiello (Baia, Naples) (MZN Z7010). Admittedly, a neotype selection for Murex aciculatus Lamarck, 1822 would also be desirable. However, given the evidence that in Ocinebrina some hidden biodiversity can be uncovered only with a genetic approach, we prefer to leave this designation to a future genetic and morphological revision of Ocinebrina aciculata throughout its entire range.

Lusitanian Province, from the central Mediterranean (Adriatic Sea) to the British Isles and Madeira.

Probably throughout the Mediterranean Sea but I have not seen specimens from Algeria and Libya. In the Atlantic, it lives up to the Scilly and Channel Islands to the north, up to Mauritania (Baie de l’Etoile), and north of Senegal, to the south. To the west it was recorded in the Canary Islands (Tenerife) by Nordsieck & Garcia-Talavera (1979: 133) and in Madeira and the Azores. On rocky shores at low tide, under stones. It may occur living as deep as 105 m.