Alvania porcupinae Gofas & Warén, 1982

Oliver, Joan Daniel, Gofas, Serge, Urgorri, Victoriano, Díaz-Agras, Guillermo & Templado, José, 2022, Rissoidae gastropods of the outer continental shelf and slope off Galicia (NW Spain), Zootaxa 5196 (1), pp. 1-45 : 19

Alvania porcupinae Gofas & Warén, 1982

( Fig. 11 )

Material examined. (1 empty shell): SPAIN • 1 sh; 43° 34.86′N, 009° 21.95′W to 43° 36.44′N, 009° 20.71′W; 1010–1112 m; 15–30 Sep. 2008; DIVA-Artabria II EBS-04 .

Remarks. Alvania porcupinae is known from the Bay of Biscay to off Canary Islands (not found in the Mediterranean) in a wide depth range (800–4700 m) ( Bouchet & Warén 1993; Hoenselaar & Goud 1998), and it is one of the few rissoids occurring at abyssal depths ( Sysoev 2014). Within the material studied only one shell ( Fig. 11a ) was found in a sample collected at 1050 m in depth. According to Bouchet & Warén (1993) A. porcupinae belongs to the same lineage as A. electa , A. adinogramma and A. cancapae , characterized by similar teleoconch features and a finely granulated protoconch. As in the case of A. electa , this species is rather variable (see Bouchet & Warén 1993 in figures 1424–1429) and needs a deep revision. The shell here studied is quite similar to the one of figure 1426 in Bouchet & Warén (1993) from off southern Morocco, bearing square reticulate sculpture ( Figs. 11a, g ), but it is somewhat smaller (1.9 mm compared to 2.3 mm in the latter) and with a low number of spiral cords. Suture slightly channeled. About forty axial ribs in the body whorl, almost orthocline, somewhat narrower than the interspaces which adapically deviated by a slight subsutural depression. The ribs are interrupted at the level of the apertural insertion, disappearing at the base. Flat spiral cords, slightly wider than the ribs and somewhat narrower than their interspaces. Paucispiral dome protoconch ( Figs. 11b–d ) with almost smooth surface and abrupt transition to the teleoconch ( Fig. 11f ).

Figures

FIGURE 11. Alvania porcupinae Gofas & Warén, 1982 (DA-II(08) EBS-04). a–b Shell (1.9 mm) in lateral and apical views; c–d Protoconch in lateral and apical views of the same shell; e Detail of its microsculpture of the protoconch; f Detail of the transition protoconch/teleoconch; g Detail of the sculpture of the teleoconch.