Nucula profundorum Smith, 1885

Wiklund, Helena, Taylor, John D., Dahlgren, Thomas G., Todt, Christiane, Ikebe, Chiho, Rabone, Muriel & Glover, Adrian G., 2017, Abyssal fauna of the UK- 1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Mollusca, ZooKeys 707, pp. 1-46 : 10-12

Nucula profundorum Smith, 1885

Material examined.

NHM_141 NHMUK 20170051, collected 2013-10-11, 13.75833 -116.69852, 4080 m. http://data.nhm.ac.uk/object/f2133256-1cad-4255-a5cb-bd5331417127

NHM_274A NHMUK 20170052, collected 2013-10-17, 13.75583 -116.48667, 4076 m. http://data.nhm.ac.uk/object/f96a470e-237e-46b4-ba85-4c6196106071

NHM_378 NHMUK 20170053.1-2, collected 2013-10-19, 13.93307 -116.71628, 4182 m. http://data.nhm.ac.uk/object/65f8d1ed-dd6a-4265-90d2-daf07491cd76

Description.

Small, trigonal- subovate. Periostracum light brown, shiny. Sculpture of fine radial lirae. Resilifer small. Hinge teeth: 5 anterior, 4 posterior. Inner shell margin finely denticulate. Voucher NHM_274A width 2 mm, height 1.8 mm (Fig. 9).

Genetic data.

GenBank NHM_141 16S-MF157457, 18S-MF157473, COI-MF157503; NHM_274A COI-MF157512; NHM_378 16S-MF157464, COI-MF157520.

Remarks.

Morphologically matches Nucula profundorum Smith, 1885 based on examination of the syntype specimens [NHMUK 1887.2.9.2919]. In the molecular analysis of nuculoid protobranchs (Fig. 12) Nucula profundorum and the Atlantic Nucula atacellana Schenck, 1939 are well supported sister species. However the N. profundorum identified from the present samples differs genetically from the N. profundorum record in GenBank (accession nr KJ950274; Jennings and Etter 2014) which we believe may be misassigned. That sample came from 1045 m in the north eastern Pacific off San Diego (Figure 10). The shell illustrated by Coan and Valentich-Scott (2012 pl 12) as N. profundorum has more hinge teeth. There may be a complex of morphologically similar species in the eastern Pacific. No genetic matches on GenBank.

Ecology.

The most abundant bivalve mollusc recorded in the ABYSSLINE sampling programme, frequently found in epibenthic sledge and box core samples from region of sediment and polymetallic nodules.