Alvania cancellata (da Costa, 1778)

Gofas, Serge, 2007, Rissoidae (Mollusca: Gastropoda) from northeast Atlantic seamounts, Journal of Natural History 41 (13 - 16), pp. 779-885 : 789

Alvania cancellata (da Costa, 1778)

( Figure 5A, B )

Material examined

Gorringe— Seamount 1 sta. DW04, 7 sh. (jv.); DW05, 3 sh. (jv., old sh.); DE09, 1 sh. (jv.); DW15, 1 sh. (jv, old sh.); DW33, 1 sh. (4.90× 2.98 mm). Seine— Seamount 1 sta. DE72, 1 sh. (jv.). Ampère— Seamount 1 sta. DE98, 7 sh. (jv. or broken).

Remarks

This species is common in the Azores (see Gofas 1990) and is capable of crossing the interarchipelago distances during its planktotrophic larval stage. However, it is extremely rare on the seamounts where it currently does not find the shallow sublittoral rubble or rocky bottoms on which it normally lives. The few shells collected may represent pseudopopulations, and some of the occurrences could even be subfossil shells which date back to Pleistocene low water stands. This species was also recorded from Gorringe by Ávila and Malaquias (2003).

Figures

Figure 5. Alvania species from Lusitanian seamounts, shared with the mainland shelf. (A) A. cancellata (da Costa, 1778), shell from Gorringe seamount, DW33 (55–70 m), actual size 4.90 mm; (B) A. cancellata, protoconch of a shell from Ampère seamount, DE98 (300–325 m); (C) A. zylensis Gofas and Warén, 1982 from Gorringe seamount, CP20 (305–320 m), actual size 2.25 mm; (D) protoconch of the same specimen; (E) A. zylensis from Ampère seamount, DW92 (117–129 m), actual size 2.00 mm; (F) A. punctura (Montagu, 1803), protoconch of a shell from Gorringe seamount, CP 20; (G) Alvania vermaasi van Aartsen, 1975, protoconch of a shell from Gorringe seamount, DW08 (470–485 m). Scale bars: 100 Mm.