Brocchinia clenchi Petit 1986

Brocchinia cf. clenchi Petit, 1986

Fig. 25A–E

Brocchinia clenchi Petit, 1986: 23–26.

Brocchinia clenchi – Verhecken 2007: 311–313.

GALICIA BANK • 5 spm and 7 sh; 43°00.12′ N, 11°57.67′ W; 1706 m; 29 Jul. 2011; BANGAL 0711 V2; MNCN • 5 sh; 42°56.77′ N, 11°58.53′ W; 1631 m; 2 Aug. 2011; BANGAL 0711 V5; MNCN • 1 spm (Fig. 25A‒B, 10.8 mm high); 42°59.61′ N, 11°58.41′ W; 1671 m; 7 Aug. 2011; BANGAL 0711 V9; MNCN • 1 spm, 6 sh; 42°41.87′ N, 11°26.71′ W; 1720 m; 8 Aug. 2011; BANGAL 0711 V10; MNCN • 5 sh; 42°28.81′ N, 11°50.03′ W; 1410 m; 8 Aug. 2011; BANGAL 0711 DR15; MNCN.

Shell rather solid, creamy white, conical and elongated, up to 10.8 mm in height, 5.4 mm width. Protoconch paucispiral, globose, of 1½ whorl, 330 µm in nucleus diameter and about 650 µm in maximum diameter, smooth, with a clear thickened edge marking the transition to teleoconch. Teleoconch with up to 5 convex whorls, first whorl with 2 initially smooth and then slightly nodulose spiral cords, with third cord appearing at the end of this whorl. Spiral sculpture formed by 3 nodulose spiral cords on last 2 whorls, and 3‒4 more basal cords almost smooth on body whorl; uppermost basal cord meeting a level close to the suture at the posterior end of aperture. Axial sculpture formed by nodulose ribs, crossed by the three equally spaced upper spiral cords. Shell entirely marked by strong axial growth lines. Suture incised, with suprasutural furrow. Base conical, with 2 smooth spiral cords that emerge from the interior of the aperture. Aperture elliptical, outer lip thin, prosocline, smooth inside. Inner lip strongly reflected, with a thin and shiny vitreous callus on the parietal area. Columella somewhat inclined to right, with 2 strong folds, posterior larger, columellar end somewhat angled at its end and forming a weak siphonal canal when it meets the outer lip.

Specimens and shells of this species were only found in the deepest BANGAL samples (1631‒1720 m), together with shells of Brocchinia azorica (Bouchet & Warén, 1985) in samples V2 and V5.

Brocchinia clenchi Petit, 1986 was originally described from the Josephine Bank at 610‒770 m depth (Petit 1986); the holotype being faintly sculptured and measuring 4.5 mm. The species was later found deeper (1350‒1360 m) in the same locality; shells and specimens were recorded from the Canary Islands (65‒1520 m), Selvagem Grande (830 m), Azores (15‒1250 m) and off Western Sahara (1000‒1100 m) (Verhecken 2002, 2007). Both extremes of the bathymetric range (15‒1520 m) are based on live collected specimens (Verhecken 2007).

Verhecken (2007: fig. 29c‒d) illustrated as B. clenchi two larger and more sculptured shells in a lot of six collected in PORCUPINE stn 28 (S of Sagres, 548 m, BMNH 1885.11.5.2607–12), which are closely similar to those from GB and were identified by Jeffreys (1885: 49) as ‘ Cancellaria mitraeformis, Brocchi’. Verhecken (2007) noted that shells of B. clenchi of similar size coming from shallow or deep waters of the Canary Islands may be faintly or strongly sculptured, whereas shells from deeper water were larger (up to 8.5 mm). He nevertheless preferred to consider one species awaiting for more material from different localities. In disagreement with this view, Rolán & Hernández (2009) described Brocchinia canariensis as different from B. clenchi. These authors also concluded that the paratype of B. clenchi (a shell of 6 mm, BMNH 1855.4.4.202, from the Canary Islands) illustrated by Petit (1986), as “possibly the type of Cancellaria pusilla H. Adams, 1869 ” (a junior primary homonym of Cancellaria pusilla G.B. Sowerby I, 1832) was different from both B. clenchi and B. canariensis, therefore their choice to describe a new species from the Canaries rather than propose a replacement name for C. pusilla.

Other N Atlantic species, as Brocchinia azorica (Bouchet & Warén, 1985) (see Fig. 25F–I), B. pustulosa Verhecken, 1991, and B. nodosa (Verrill & S. Smith, 1885) have the inside of the outer lip smooth, but are larger and have a more solid and conical shell with stronger nodulose sculpture; B. azorica and B. nodosa also have multispiral protoconchs. The S Atlantic B. decapensis (Barnard, 1960) is the largest Atlantic species (up to 27.3 mm), and has also a more solid and conical shell. Finally, the NE Brazilian species Brocchinia verheckeni Barros & Lima, 2007 and B. harasewychi Barros & Lima, 2007, have a paucispiral protoconch, but they are smaller (up to 4.4 and 6.3 mm, respectively), less elongated than the species from GB, and have a stronger nodulose sculpture; B. verheckeni has lyrae inside the outer lip, whereas B. harasewychi lacks them (see Barros & Lima 2007).