Pusillina cf. radiata ( Philippi, 1836 )

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 : 34

Pusillina cf. radiata ( Philippi, 1836)

( Fig. 21a–c )

Material examined. (23 empty shells and 2 with soft parts, in 8 samples): SPAIN • 1 sPc (juv); 43° 35.451′N, 008° 34.432′W to 43° 34.810′N, 008° 35.407′W; 153– 151 m; 08–15 SeP. 2002; DIVA-Artabria I EBS-150 • 2 sh; 43° 48.421′N, 008° 51.453′W to 43° 49.160′N, 008° 51.091′W; 599–607 m; 10–20 SeP. 2003; DIVA-Artabria I DRN-600 • 1 sPc (juv); 43° 34.127′N, 008° 36.562′W to 43° 34.820′N, 008° 35.585′W; 152– 149 m; 10–20 SeP. 2003; DIVA-Artabria I EBS-150 • 6 sh; 43° 38.812′N, 009° 07.949′W to 43° 39.841′N, 009° 07.405′W; 999–1001 m; 17–28 Sep. 2004; VERTIDOS GA-DRN-1000 • 6 frg; 43° 38.105′N, 009° 02.006′W to 43° 37.738′N, 009° 00.905′W; 836– 826 m; 17–28 SeP. 2004; VERTIDOS GA-AT-800 • 2 sh; Polygon delimited by Points 44° 10.000′ N, 009° 00.000′ W /44° 10.000′ N, 008° 35.000′ W/44° 00.000′ N; 009° 00.000′ W/44° 07.000′ N; 008° 35.000′ W; 480–600 m; SARRIDAL (2006–2007) SARRI-2 • 6 sh; 44° 11.652′N, 008° 58.152′W to 44° 11.539′N, 008° 57.574′W; 908–1106 m; 15–24 Jul. 2008; A SELVA DRN-7 • 1 sh; 44° 08.461′N, 009° 04.634′W to 44° 08.607′N, 009° 04.413′W; 917– 896 m; 15–24 Jul. 2008; A SELVA DRN-7-1 .

Remarks. It is a Mediterranean species with isolated records in the Atlantic coasts ( Verduin 1976) usually in seagrass meadows ( Gofas & Oliver 2011). Verduin (1976) pointed out the extreme variability of this species (with some local forms), whose precise delimitation is not clear. A thorough review of most species of genus Pusillina , including genetic analysis, is necessary to elucidate their taxonomic status.

The presence of some juvenile shells in our samples, attributed with doubts to P. radiata ( Figs. 21a–b ) is considered accidental; probably washed away by currents. Only two shells with soft parts were found in samples obtained at 150 m. The protoconch is shown in Figure 21c .

Figures

FIGURE 21. Pusillina cf. radiata (Philippi, 1836). a–b Juvenile eroded shells (a: 1.6 mm; b: 1.7 mm) (SE:DRN-7); c Protoconch (VE:GA-AT-800); d Alvania cancellata (Da Costa, 1778) (0.96 mm) (VE:AG-EBS-150); e Crisilla semistriata (Montagu, 1808) (1.9 mm) (SE-08:EBS14); f Onoba semicostata (Montagu, 1803) (1.7 mm) (SA:SARRI-3); g Manzonia crassa (Kanmacher, 1798) (2.1 mm) (SE:DRN7).