taxonID	type	description	language	source
FF361D1B2547F64FFC53FB76FBBC576A.taxon	type_taxon	TYPE SPECIES. — Pecten (Propeamussium) ceciliae de Gregorio, 1884 by original designation.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2547F648FCA6FA71FE9B5746.taxon	description	(Fig. 1 A-E)	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2547F648FCA6FA71FE9B5746.taxon	materials_examined	TYPE LOCALITY. — Challenger Stn 158, 50 ° 01 ’ S, 123 ° E, southern Indian Ocean, depth 3292 m. MATERIAL EXAMINED. — Walters Shoal • 1 rv, 1 lv; south plain; 33 ° 52 ’ S, 44 ° 05 ’ E; depth 1539 - 1615 m; 11. V. 2017; Stn CP 4913; MNHN-IM- 2013 - 67062 • 2 pr, living, DNA tissue sample, 9 rv, 9 lv; south plain; 33 ° 55 ’ S, 44 ° 03 ’ E; depth 1598 - 1714 m; 11. V. 2017; Stn CP 4914; MNHN-IM- 2017 - 3544.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2547F648FCA6FA71FE9B5746.taxon	distribution	DISTRIBUTION. — A relatively deep-water species, widely distributed in the south-west Pacific, Philippines, Indonesia, New Caledonia, also western Australia and the Indian ocean from the Arabian Sea to South Africa; collected at two neighbouring stations on the surrounding plains of Walters Shoal CP 4913 and CP 4914, living specimens retrieved at depths between 1598 and 1714 m.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2547F648FCA6FA71FE9B5746.taxon	discussion	REMARKS Propeamussium meridionale was found alive at one station (CP 4914), at least two paired valves and several disarticulated ones with soft parts still attached to the left valves. In a previous paper (Dijkstra & Maestrati 2015), the authors did not report its occurrence in the Mozambique Channel from the recent campaigns Miriky and Mainbaza, where only four stations out of a total of 168, exceeded 1000 m depth (1000 - 1400 m).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F648FECCFA51FDF054B3.taxon	type_taxon	TYPE SPECIES. — Pecten (Pleuronectes) duodecimlamellatus Bronn, 1832 by original designation.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F648FECCFA51FDF054B3.taxon	discussion	NOTE. — For synonymy, diagnosis, distribution and discussion of the genus Parvamussium see Dijkstra (1995: 25).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F649FECCF930FA2357A6.taxon	description	(Figs 2; 9 C-D) urn: lsid: zoobank. org: act: 2 B 91976 D-FB 7 E- 4 B 55 - 8 C 92 - 30 A 95 EB 42535	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F649FECCF930FA2357A6.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Walters Shoal • 1 lv; slopes; 32 ° 46 ’ S, 44 ° 18 ’ E; depth 964 - 965 m; 10. V. 2017; Stn CP 4911; MNHN-IM- 2000 - 34159. Paratypes. Walters Shoal • 1 lv, 1 rv; same data as for holotype; MNHN-IM- 2000 - 34160. OTHER MATERIAL. — Walters Shoal – slopes • 4 lv, 1 rv; 33 ° 32 ’ S, 44 ° 00 ’ E; depth 1000 - 1052 m; 9. V. 2017; Stn CP 4905; MNHNIM- 2017 - 3571 • 8 lv, 6 rv; 33 ° 29 ’ S, 44 ° 00 ’ E; depth 900 - 950 m; 9. V. 2017; Stn CP 4908; NBC • 2 rv; 32 ° 45 ’ S, 44 ° 06 ’ E; depth 966 - 968 m; 10. V. 2017; Stn CP 4910; MNHN-IM- 2017 - 3570 •> 50 lv,> 50 rv; 32 ° 46 ’ S, 44 ° 18 ’ E; depth 964 - 965 m; 10. V. 2017; Stn CP 4911; MNHN-IM- 2018 - 6314 • 5 lv, 18 rv; 33 ° 49 ’ S, 44 ° 23 ’ E; depth 961 - 966 m; 10. V. 2017; Stn CP 4912; MNHN-IM- 2018 - 6315.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F649FECCF930FA2357A6.taxon	distribution	DISTRIBUTION. — Known only from the slopes of Walters Shoal, 32 ° 45 ’ S- 33 ° 49 ’ S, 44 ° 00 ’ E- 44 ° 23 ’ E; on soft substrate at 950 - 1000 m, shells only, no live-taken specimens.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F649FECCF930FA2357A6.taxon	etymology	ETYMOLOGY. — From cancelli L – lattice-work; in reference to the small latticed sculpture on the left valve.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F649FECCF930FA2357A6.taxon	description	DESCRIPTION Shell up to 6.8 mm in height, circular, semi-transparent to opaque, almost equivalve, rather inflated, left valve slightly more convex than right valve, auricles unequal in shape and size, umbonal angle c. 110 °, colour whitish. Left valve with reticulated sculpture, intersecting, closely spaced (10 per mm) commarginal and radial sculpture throughout shell disc, commencing after 1.5 mm shell height and extending to ventral margin, more closely spaced near periphery. Radial riblets and commarginal lamellae of even strength. Auricles with closely spaced commarginal lamellae, finer and more closely arranged on posterior than on anterior. Right valve with regularly arranged commarginal lirae (10 per mm on central part of disc). Anterior auricle, demarcated from shell disc, with closely spaced, coarse commarginal lamellae, more delicate and more close set on posterior. Hinge line straight. Byssal notch shallow, byssal fasciole narrow. Interior with 8 - 10 strongly developed ribs, one interstitial rudimentary in some specimens near the ventral margin, one weak auricular on each side, starting at 1 mm shell height and reaching close to ventral margin. Prodissoconch (Figs 2 G; 9 C-D): length 150 µm. Dimensions: holotype, height 7 mm, width 6.5 mm, convexity 1.1 mm.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2540F649FECCF930FA2357A6.taxon	discussion	REMARKS The most similar congeneric species is Parvamussium biformatum Dijkstra & Maestrati, 2008 from bathyal depths (453 - 542 m) off the Solomon Islands. Parvamussium cancellinum n. sp. morphologically differs from P. biformatum by having a latticed sculpture throughout on the left valve (P. biformatum has more widely spaced commarginal lamellae in early growth stages, and a more delicate reticulate sculpture in late growth stages), and by having more numerous internal riblets that develop earlier (P. cancellinum n. sp. 10, P. biformatum 8). Another close congener is Parvamussium retiaculum Dijkstra, 1995, known from bathyal depths of the south-western Pacific (Dijkstra & Marshall 1997: 81; Dijkstra 2001: 85; Dijkstra & Maestrati 2008: 93, 2012: 392, 2017: 477). However, the present species differs from P. retiaculum by having a circular shape (P. retiaculum is longer than wide); by having a more closely spaced latticed sculpture on the left valve (P. retiaculum has a reticulate sculpture of widely spaced commarginal lamellae and narrowly spaced radial riblets), and by having fewer internal riblets, which start earlier (P. cancellinum n. sp. 8 - 10, P. retiaculum 12). A somewhat similar congener with latticed sculptured is Parvamussium retiolum Dijkstra, 1995, also known from bathyal depths of the south-western Pacific (Dijkstra 2001: 85; Dijkstra & Marshall 2008: 10; Dijkstra & Maestrati 2008: 93, 2013: 473, 2017: 477). However, the present species is much smaller (P. cancellinum up to 7 mm, P. retiolum up to 16 mm in height), and has a circular shape (P. retiolum is longer than wide and posteriorly oblique).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2541F64BFC17FA31FD6A55C0.taxon	description	(Figs 3; 9 G-H) urn: lsid: zoobank. org: act: D 6 BA 36 F 7 - 9 D 1 C- 47 F 3 - 9708 - 6 D 4 B 1660 ACCF	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2541F64BFC17FA31FD6A55C0.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Walters Shoal • 1 pr; slopes; 33 ° 16 ’ S, 43 ° 50 ’ E; depth 377 - 382 m; 2. V. 2017; R / V Marion Dufresne Stn DW 4881; MNHN-IM- 2013 - 67057. Paratypes. Walters Shoal • 1 lv + 1 rv; slopes; 33 ° 16 ’ S, 43 ° 50 ’ E; depth 377 - 382 m; 2. V. 2017; R / V Marion Dufresne Stn DW 4881; MNHN-IM- 2013 - 67059 • 1 lv + 1 rv; slopes; 33 ° 16 ’ S, 43 ° 50 ’ E; depth 377 - 382 m; 2. V. 2017; R / V Marion Dufresne Stn DW 4881; MNHN-IM- 2000 - 34161. OTHER MATERIAL. — Walters Shoal – Slopes • 2 lv, 5 rv; 33 ° 10 ’ S, 43 ° 49 ’ E; depth 217 - 256 m; 1. V. 2017; Stn DW 4877; MNHNIM- 2017 - 3555 • 1 pr; 33 ° 09 ’ S, 43 ° 50 ’ E; depth 221 - 256 m; 1. V. 2017; Stn DW 4878; MNHN-IM- 2017 - 3551 • 9 lv, 50 rv; 33 ° 16 ’ S, 43 ° 50 ’ E; depth 377 - 382 m; 2. V. 2017; Stn DW 4881; MNHN-IM- 2017 - 3548 / 3557 •> 50 pr; 33 ° 14 ’ S, 43 ° 51 ’ E; depth 290 - 326 m; 2. V. 2017; Stn DW 4883; MNHN-IM- 2017 - 3522 • 4 lv, 20 rv; 33 ° 17 ’ S, 43 ° 55 ’ E; depth 272 - 380 m; 3. V. 2017; Stn DW 4885; MNHN-IM- 2018 - 6310 • 18 lv, 69 rv; 33 ° 17 ’ S, 43 ° 56 ’ E; depth 573 - 582 m; 3. V. 2017; Stn DW 4886; MNHNIM- 2017 - 3549 / 3554 • 7 lv, 16 rv; 33 ° 17 ’ S, 43 ° 57 ’ E; depth 599 - 640 m; 3. V. 2017; Stn DW 4887; MNHN-IM- 2017 - 3553 • 1 pr; 33 ° 10 ’ S, 43 ° 57 ’ E; depth 299 - 311 m; 3. V. 2017; Stn DW 4888; MNHN-IM- 2017 - 3556 • 6 lv, 3 rv; 33 ° 09 ’ S, 43 ° 58 ’ E; depth 353 - 465 m; 3. V. 2017; Stn DW 4889; MNHN-IM- 2017 - 3547 / 3550 • 7 lv, 15 rv; 33 ° 09 ’ S, 43 ° 59 ’ E; depth 492 - 588 m; 4. V. 2017; Stn DW 4890; MNHN-IM- 2018 - 6309 • 3 lv; 33 ° 16 ’ S, 43 ° 58 ’ E; depth 623 - 629 m; 4. V. 2017; Stn DW 4893; MNHN-IM- 2017 - 3552 • 2 pr; 33 ° 09 ’ S, 43 ° 49 ’ E; depth 238 - 283 m; 5. V. 2017; Stn DW 4895; MNHN-IM- 2018 - 6311 • 1 pr, 1 lv, 1 rv; 33 ° 07 ’ S, 43 ° 51 ’ E; depth 325 - 357 m; 5. V. 2017; Stn DW 4896; MNHN-IM- 2017 - 3546 • 1 pr, 1 rv; 33 ° 09 ’ S, 43 ° 59 ’ E; depth 490 - 584 m; 5. V. 2017; Stn DW 4897; MNHN-IM- 2018 - 6308.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2541F64BFC17FA31FD6A55C0.taxon	distribution	DISTRIBUTION. — Known only from Walters Shoal 33 ° 07 ’ S- 33 ° 17 ’ S, 43 ° 49 ’ E- 43 ° 59 ’ E; inhabits bathyal zones characterized by soft substrates, occurring at depths ranging from 221 to 584 m, with a typical distribution between 256 and 490 m.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2541F64BFC17FA31FD6A55C0.taxon	etymology	ETYMOLOGY. — From laetus L. – richly coloured; in reference to the multi-coloured left shell disc.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2541F64BFC17FA31FD6A55C0.taxon	description	DESCRIPTION Shell up to 11 mm in height, almost circular, somewhat oblique posteriorly, opaque, weakly inflated, auricles unequal, umbonal angle c. 110 °, multi-coloured. The shell disc of left valve in early ontogeny glossy and smooth to 1 mm below umbo, followed for 1 mm by dull and smooth surface of pre-radial stage. Numerous (25 - 35) irregularly spaced delicate radial riblets starting after 2 mm below umbonal apex, increasing in number towards ventral margin, and crossed by very closely spaced (c. 12 per mm) over-running fine commarginal lamellae, showing a somewhat reticular sculpture. Commarginal lamellae more closely arranged near periphery (c. 15 per mm). Anterior auricle larger in size than posterior one (3.5: 2), and both set with very weak radial riblets (6 - 12) and over-running closely spaced lamellae, pronounced on anterior and weaker on posterior. Right valve sculptured throughout with delicate commarginal lirae (c. 8 per mm) and semi-transparent, internal riblets visible through shell disc. Anterior auricle somewhat demarcated from the shell disc with 6 - 10 fine radial riblets and closely set commarginal lamellae, more prominent on the dorsal margin. Posterior auricle more continuous with shell disc, sculptured with very closely set, fine commarginal lamellae near posterior margin. Internal radial riblets equally spaced, numbering 10 in most specimens, a few specimens with one or two interstitial rudimentary riblets in late growth stage near periphery; riblets small, beginning c. 3 mm below dorsal margin and extending to ventral submarginal area. A small auricular lira produced on each border. Byssal notch small and shallow, ctenolium on suture absent. Hinge line straight; cardinal crura rather broad and resilial pit triangular. Colour of left valve variegated, uniformly whitish, creamy or brownish, or brightly maculated with multi-coloured dots and / or streaks. Prodissoconch (Figs 3 I; 9 G-H): Length 150 µm. Dimensions: Holotype, height 9.2 mm, width 9.1 mm, convexity 2.0 mm.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2541F64BFC17FA31FD6A55C0.taxon	discussion	REMARKS The most similar congeneric species is Parvamussium virgatum Dijkstra, 1991 from upper bathyal depths of the western, south-western and southern Pacific (Dijkstra 1991: 20, 2001: 88; Dijkstra & Kastoro 1997: 265; Dijkstra & Maestrati 2008: 97, 2017: 477). The present species differs from P. virgatum in having a more posteriorly oblique shell shape (P. virgatum is circular, see Dijkstra 1991: fig. 72), in having a shorter glossy surface in the early growth stage of the left valve (P. laetum n. sp. 1 mm, P. virgatum 2 mm, see Dijkstra 1991: fig. 74), in having more prominent sculpture on the left valve, comprising radial riblets and commarginal lamellae (weaker and finer in P. virgatum, see Dijkstra 1991: figs 62, 64 and Dijkstra & Kastoro 1997: fig. 99) and in the bright colouration of the left valve (P. virgatum is opaque whitish). Other morphological characters of both species are almost similar. Another morphologically close congener is Parvamussium formosum (Melvill in Melvill & Standen, 1907), known from upper bathyal depths of the north and south-western Indian Ocean (Dijkstra & Knudsen 1998: 45; Dijkstra & Janssen 2013: 191; Dijkstra & Maestrati 2015: 601). Parvamussium laetum n. sp. is characterized by a more prominent sculpture of radial riblets and commarginal lamellae on the left valve while P. formosum is almost smooth on the central part of the shell disc with a very weak radial lateral sculpture (see Oliver 1992: 70, Fig. 6). Additionally, Parvamussium laetum n. sp. has a constant number of internal ribs (10 versus P. formosum 8 - 11, with occasionally additional rudimentary interstitial riblets) and has in general a more colourful left valve.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2543F644FC78FF35FEB05466.taxon	description	(Fig. 4; 9 I-J) urn: lsid: zoobank. org: act: 969 E 5 D 6 E- 8 E 1 C- 4 D 57 - 9 CC 7 - 7 BCCD 734 E 2 B 6	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2543F644FC78FF35FEB05466.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Walters Shoal • 1 pr; slopes; 33 ° 09 ’ S, 43 ° 59 ’ E; depth 492 - 588 m; 4. V. 2017; Stn DW 4890; MNHN-IM- 2013 - 67061. Paratypes. Walters Shoal • 1 lv + 1 rv; same data as for holotype; MNHN-IM- 2000 - 34162. OTHER MATERIAL. — Walters Shoal – Slopes • 1 lv; 32 ° 46 ’ S, 44 ° 18 ’ E; depth 964 - 965 m; 10. V. 2017; Stn CP 4911; NBC • 5 lv; 33 ° 17 ’ S, 43 ° 57 ’ E; depth 599 - 640 m; 3. V. 2017; Stn DW 4887; MNHNIM- 2017 - 3566 / 3568 • 2 lv; 33 ° 09 ’ S, 43 ° 59 ’ E; depth 492 - 588 m; 4. V. 2017; Stn DW 4890; MNHN-IM- 2017 - 3563 • 1 rv; 33 ° 12 ’ S, 44 ° 01 ’ E; depth 650 - 653 m; 4. V. 2017; Stn DW 4891: MNHNIM- 2017 - 3561 • 12 lv, 19 rv; 33 ° 12 ’ S, 44 ° 01 ’ E; depth 624 - 646 m; 4. V. 2017; Stn DW 4892; MNHN-IM- 2017 - 3564 • 1 rv; 33 ° 09 ’ S, 43 ° 59 ’ E; depth 490 - 584 m; 5. V. 2017; Stn DW 4897; MNHNIM- 2018 - 6313 • 1 pr, 24 lv, 49 rv; 33 ° 09 ’ S, 44 ° 01 ’ E; depth 652 - 668 m; 6. V. 2017; Stn DW 4898; MNHN-IM- 2017 - 3565 / 3569 • 35 lv,> 50 rv; 33 ° 09 ’ S, 44 ° 02 ’ E; depth 707 - 720 m; 6. V. 2017; Stn DW 4899; MNHN-IM- 2017 - 3562 / 3567 • 18 lv, 23 rv; 33 ° 10 ’ S, 44 ° 01 ’ E; depth 660 - 670 m; 6. V. 2017; Stn DW 4900; MNHN-IM- 2017 - 3558 • 1 pr, 1 lv; 33 ° 11 ’ S, 44 ° 01 ’ E; depth 652 m; 6. V. 2017; Stn DW 4904; MNHN-IM- 2017 - 3560 • 1 lv; 33 ° 26 ’ S, 44 ° 00 ’ E; depth 799 - 837 m; 9. V. 2017; Stn CP 4906; MNHN-IM- 2017 - 3559.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2543F644FC78FF35FEB05466.taxon	distribution	DISTRIBUTION. — Known only from the bathyal zone off Walters Shoal, 33 ° 09 ’ S- 33 ° 26 ’ S, 43 ° 57 ’ E- 44 ° 02 ’ E; on soft substrata at a depth range of 492 - 588 m and 964 - 965 m.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2543F644FC78FF35FEB05466.taxon	etymology	ETYMOLOGY. — From pustulatus L. – with vesicles; in reference to the vesicular sculpture of the left valve.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2543F644FC78FF35FEB05466.taxon	description	DESCRIPTION Shell small, height up to 11 mm, circular, almost equilateral, weakly inflated, anterior auricle slightly larger than posterior, semi-transparent, opaque whitish in coloration. Left valve disc smooth, somewhat glossy in early growth stage to c. 2 mm from dorsal margin, followed by c. 10 radial rows of distant vesicles (c. 5 - 6 per mm) increasing in number by intercalated radial rows of vesicles to c. 60 - 80 near ventral margin. Commarginal sculpture on the disc absent. The anterior auricle with prominent, closely spaced, commarginal lamellae (c. 8 per mm), the posterior auricle nearly identical, commarginal lamellae slightly more closely spaced and less prominent (c. 10 per mm). The hinge line straight. The right valve with very closely spaced, delicate commarginal lirae (c. 10 - 12 per mm). The anterior auricle slightly twisted, strongly marked with widely spaced commarginal lamellae, the posterior auricle with fine, very closely spaced commarginal lamellae. The byssal notch narrow and shallow. Internal riblets prominent, nine plus one auricular on the posterior side; more widely spaced centrally than laterally, start in early growth stage and extend to ventral submarginal area. Prodissoconch (Fig. 4 G; 9 I-J): length 240 µm. Dimensions: holotype, height 11.0 mm, width 11.2 mm, convexity 2.9 mm.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2543F644FC78FF35FEB05466.taxon	discussion	REMARKS The only similar congeneric species is Parvamussium vesiculosum Dijkstra & Maestrati, 2013, known by empty shells from bathyal depths of the Tarava Seamounts and the Society Islands (French Polynesia). Parvamussium pustulatum n. sp. morphologically differs from P. vesiculosum in having a more delicate vesicular sculpture on the left valve of more radially arranged vesicles (P. pustulatum n. sp. c. 60 - 80, P. vesiculosum c. 40), in having less, commencing earlier, internal riblets (P. pustulatum n. sp. 9 + 1 auricular, P. vesiculosum 12 + 2 auricular).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF644FEDFF970FDE955C0.taxon	type_taxon	TYPE SPECIES. — Pecten pustulosus Verrill, 1872 [synonym of Pecten hoskynsi E. Forbes, 1844] by subsequent designation (Sykes et al. 1898: 75).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF644FEDFF970FDE955C0.taxon	discussion	REMARK For synonymy, diagnosis, distribution and discussion of the genus Cyclopecten see Dijkstra (1995: 41).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF645FC33FB11FBC75725.taxon	description	(Figs 5; 9 A, B) urn: lsid: zoobank. org: act: FB 79 FB 69 - 1 E 3 D- 4715 - AA 94 - A 4 E 996634 C 50	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF645FC33FB11FBC75725.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Walters Shoal • 1 lv; slopes; 33 ° 49 ’ S, 44 ° 23 ’ E; depth 961 - 966 m; 10. V. 2017; Stn CP 4912; MNHN-IM- 2000 - 34163. Paratypes. Walters Shoal • lv + 1 rv; same as for holotype; MNHNIM- 2000 - 31164.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF645FC33FB11FBC75725.taxon	distribution	DISTRIBUTION. — Known only from the type locality.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF645FC33FB11FBC75725.taxon	etymology	ETYMOLOGY. — This new species is named after Victor Broi, captain of the R / V Marion-Dufresne, serving on his last cruise before retirement.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF645FC33FB11FBC75725.taxon	description	DESCRIPTION Shell up to 4.8 mm in height, fragile, semi-transparent, circular, inequivalve, almost equilateral, auricles unequal in size and shape, umbonal angle c. 110 °, whitish opaque. Prodissoconch length 160 µm. Left valve with narrow but distinct commarginal hollow curved lamellae, widely spaced, more closely spaced in late growth stage. Delicate radial sculpture of wavy radial lines, more definitive at abutment with commarginal lamellae, not intersecting. The lamellae continued on the anterior and posterior auricles, although closer spaced. Right valve with early prodissoconch quite smooth, gradual onset of closely spaced, regularly arranged commarginal striae. Auricles weakly sculptured with commarginal striae, anterior auricle with distinct radial folds. Hinge line straight, dorsal margin weakly denticulate. Internal surface smooth. Byssal notch well developed, byssal fasciole narrow, no ctenolium. Prodissoconch (Figs 5 G; 9 A, B): length 160 µm. Dimensions: holotype, height 4.8 mm, width 4.8 mm, convexity 0.9 mm.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254CF645FC33FB11FBC75725.taxon	discussion	REMARKS The most similar congeneric species is Cyclopecten cincinnatus Dijkstra & Gofas, 2004 from bathyal depths of the northeastern Atlantic Lusitanian seamounts. Cyclopecten broii n. sp. morphologically differs from C. cincinnatus in having fewer and more widely spaced commarginal lamellae (C. broii n. sp. c. 6, C. cincinnatus 6 - 10), in having weaker commarginal lamellae on the left valve (C. cincinnatus more prominent and curved), in having finer and weaker interlamellar radial striae, even lacking anteriorly (C. cincinnatus with more prominent striae, commencing earlier). Other morphological characters of both species are identical. Another comparable species with somewhat similar commarginal sculpture and weak interlamellar striae on the left valve is Parvamussium australanum Dijkstra & Maestrati, 2010, from bathyal depths off the Austral Islands (French Polynesia). C broii n. sp. differs from P. australanum in size (C. broii n. sp. almost 5 mm in height, P. australanum 11.5 mm), in shape (C. broii n. sp. is slightly more oblong, P. australanum circular) and in internal riblets (lacking in C. broii n. sp., numerous in P. australanum).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254DF646FC22FAB1FC6255C0.taxon	description	(Fig. 6; 9 K-L) urn: lsid: zoobank. org: act: 46 E 1 FF 67 - 7 E 99 - 455 B- 882 C- 4 FBAEE 0 E 12 FC	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254DF646FC22FAB1FC6255C0.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Walters Shoal • 1 pr; slopes; 33 ° 08 ’ S, 44 ° 02 ’ E; depth 700 - 711 m; 7. V. 2017; Stn CP 4902; MNHN-IM- 2000 - 34165. Paratypes. Walters Shoal • 2 lv + 2 rv; same data as for holotype; MNHN-IM- 2000 - 34166. OTHER MATERIAL. — Walters Shoal – Slopes • 1 pr; 33 ° 11 ’ S, 44 ° 01 ’ E; depth 620 - 642 m; 7. V. 2017; Stn CP 4903; NBC • 1 lv, 1 rv; 33 ° 17 ’ S, 43 ° 56 ’ E; depth 573 - 582 m; 3. V. 2017; Stn DW 4886; MNHN-IM- 2017 - 3574 • 1 lv, 1 rv; 33 ° 17 ’ S, 43 ° 57 ’ E; depth 599 - 640 m; 3. V. 2017; Stn DW 4887; MNHN-IM- 2017 - 3575 • 1 lv, 2 rv; 33 ° 12 ’ S, 44 ° 01 ’ E; depth 624 - 646 m; 4. V. 2017; Stn DW 4892; MNHN-IM- 2017 - 3577 • 3 lv, 1 rv; 33 ° 09 ’ S, 44 ° 01 ’ E; depth 652 - 668 m; 6. V. 2017; Stn DW 4898; MNHN-IM- 2000 - 34166 • 2 lv, 1 rv; 33 ° 09 ’ S, 44 ° 02 ’ E; depth 707 - 720 m; 6. V. 2017; Stn DW 4899; MNHN-IM- 2017 - 3576; MNHN-IM- 2018 - 6321.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254DF646FC22FAB1FC6255C0.taxon	distribution	DISTRIBUTION. — Known only from the slopes of Walters Shoal, on soft substrate at 620 - 711 m.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254DF646FC22FAB1FC6255C0.taxon	etymology	ETYMOLOGY. — This new species is named after François Simard, Deputy Director of IUCN Global Marine and Polar Programme, and Principal Investigator of the FFEM-Southwest Indian Ocean project, under the umbrella of which the Walters Shoal expedition took place.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254DF646FC22FAB1FC6255C0.taxon	description	DESCRIPTION Shell up to 6 mm in height, circular, inequivalve, left valve slightly more inflated than right valve, auricles nearly equal in size, umbonal angle c. 125 °, whitish opaque. Left valve with regularly arranged, very narrowly spaced, commarginal lamellae (8 - 10 per mm), numerous (10 - 12 per mm), prominent, hemitubular scales (erect hollow spines), arrangement in radial rows, multiplying by intercalation. Crowded microscopic granules between the commarginal lamellae. Auricles with sculpture identical to disc surface. Right valve smooth and glossy near umbonal area to c. 1 mm shell height, regular commarginal lirae, very close-set, transformation into more widely spaced, undulating commarginal lamellae with delicate spines near ventral margin. Granulate microsculpture between commarginal lirae and lamellae. Anterior auricle with three radial riblets covered with fine commarginal lamellae. Posterior auricle almost continuous with disc, surface with very close-set commarginal lirae. Hinge line straight. Antero-dorsal margin with scales, squamae weakly developed on postero-dorsal margin. Byssal notch deep, byssal fasciole broad. Prodissoconch (Figs 6 G; 9 K-L): Length 280 µm. Dimensions: holotype, height 5.1 mm, width 5.8 mm, convexity 1.0 mm.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254DF646FC22FAB1FC6255C0.taxon	discussion	REMARKS The most similar congeneric species is Cyclopecten horridus Dijkstra, 1995 from bathyal depths of the south-western Pacific and off South Africa (Dijkstra & Marshall 1997: 87, 2008: 16; Dijkstra & Maestrati 2015: 617). The present species morphologically differs from C. horridus in having a much more delicate sculpture on the left valve of hemitubular scales on the commarginal lamellae (10 - 12 scales in C. simardi n. sp. vs 6 - 8 in C. horridus), in having more closely spaced commarginal lamellae in late growth stage, with more delicate spinous scales, in having a finer sculpture on the right valve with more closely arranged commarginal lamellae, almost lacking spinose scales (C. horridus with wider set commarginal spinous lamellae). Another comparable species of similar shape and size, and with hemitubular sculpture on the left valve is Parvamussium araneum Dijkstra, 1991 from bathyal depths of the south-western Pacific (Dijkstra & Kastoro 1997: 255; Dijkstra & Maestrati 2008: 85; Dijkstra 2011: 40, 2013: 17). Cyclopecten simardi n. sp. is morphologically distinguishable from P. araneum in lacking radial sculpture on the left valve (P. araneum also has radial sculpture with hemitubular scales on the intersections of the radial riblets and commarginal lamellae), and in having a closer spaced commarginal sculpture, and in lacking internal riblets (P. araneum has rudimentary, laterally placed riblets).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF647FF3FF9B1FCA854C7.taxon	discussion	REMARK Formerly attributed to Wilkes (1810), but that work is not entirely binominal. For a diagnosis see Dijkstra (2013: 24).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF647FED5F8D0FB725486.taxon	type_taxon	TYPE SPECIES. — Chlamys famigerator Iredale, 1925 [synonym of Pecten pulleineanus Tate, 1887] by original designation.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF647FED5F8D0FB725486.taxon	discussion	REMARK For diagnosis, distribution and discussion of the genus Talochlamys see Dijkstra & Marshall (2008: 51).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF640FC12F93DFC6A5705.taxon	description	(Figs 7; 9 E-F) urn: lsid: zoobank. org: act: FE 204 DE 4 - 4 D 24 - 4448 - 9 DBE-B 2 EEEAC 3669 D	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF640FC12F93DFC6A5705.taxon	materials_examined	MATERIAL EXAMINED. — Holotype. Walters Shoal • 1 pr, living, DNA tissue sample; slopes; 33 ° 10 ’ S, 43 ° 49 ’ E; depth 217 - 256 m; 1. V. 2017; Stn DW 4877; MNHN-IM- 2013 - 67070. Paratypes. Walters Shoal • 3 pr; same data as for holotype; living, DNA tissue samples; MNHN-IM- 2013 - 67069, 67071, 67072. OTHER MATERIAL. — Walters Shoal – Slopes • 20 lv, 21 rv; 33 ° 10 ’ S, 43 ° 49 ’ E; depth 217 - 256 m; 1. V. 2017; Stn DW 4877; MNHN-IM- 2017 - 3515 • 5 pr, 9 lv, 2 rv; 33 ° 09 ’ S, 43 ° 50 ’ E; depth 221 - 256 m; 1. V. 2017; Stn DW 4878; MNHN-IM- 2017 - 3509 • 3 pr, 4 lv, 5 rv; 33 ° 17 ’ S, 43 ° 52 ’ E; depth 288 - 300 m; 1. V. 2017; Stn DW 4879; MNHN-IM- 2017 - 3512 • 2 pr, 30 lv, 9 rv; 33 ° 17 ’ S, 43 ° 51 ’ E; depth 275 - 318 m; 1. V. 2017; Stn DW 4880; MNHNIM- 2017 - 3504 • 5 lv, 4 rv; 33 ° 16 ’ S, 43 ° 50 ’ E; depth 377 - 382 m; 2. V. 2017; Stn DW 4881; MNHN-IM- 2017 - 3505 • 1 lv; 33 ° 14 ’ S, 43 ° 51 ’ E; depth 290 - 326 m; 2. V. 2017; Stn DW 4883; MNHNIM- 2018 - 6319 • 5 pr, 20 lv, 9 rv; 33 ° 17 ’ S, 43 ° 55 ’ E; depth 272 - 380 m; 3. V. 2017; Stn DW 4885; MNHN-IM- 2017 - 3514 • 10 lv, 3 rv; 33 ° 10 ’ S, 43 ° 57 ’ E; depth 299 - 311 m; 3. V. 2017; Stn DW 4888; MNHN-IM- 2017 - 3506 / 3573; MNHN-IM- 2018 - 6316 • 6 lv, 1 rv; 33 ° 09 ’ S, 43 ° 58 ’ E; depth 353 - 465 m; 3. V. 2017; Stn DW 4889; MNHN-IM- 2017 - 3508 / 3510; MNHN-IM- 2018 - 6317 • 1 lv; 33 ° 12 ’ S, 44 ° 01 ’ E; depth 650 - 653 m; 4. V. 2017; Stn DW 4891; MNHN-IM- 2018 - 6318 • 4 lv, 2 rv; 33 ° 12 ’ S, 44 ° 01 ’ E; depth 624 - 646 m; 4. V. 2017; Stn DW 4892; MNHN-IM- 2017 - 3572; MNHN-IM- 2018 - 6320 • 6 pr, 18 lv, 8 rv; 33 ° 09 ’ S, 43 ° 50 ’ E; depth 199 - 261 m, 5. V. 2017; Stn DW 4894; MNHN-IM- 2017 - 3507 • 12 lv, 8 rv; 33 ° 09 ’ S, 43 ° 49 ’ E; depth 238 - 283 m; 5. V. 2017; Stn DW 4895; MNHN-IM- 2017 - 3511 • 7 lv, 3 rv; 33 ° 07 ’ S, 43 ° 51 ’ E; depth 325 - 357 m; 5. V. 2017; Stn DW 4896; MNHNIM- 2017 - 3513.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF640FC12F93DFC6A5705.taxon	distribution	DISTRIBUTION. — Known only from the slopes of Walters Shoal, living in the bathyal zone on soft substrata between 199 - 261 m and 650 - 653 m.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF640FC12F93DFC6A5705.taxon	etymology	ETYMOLOGY. — This new species is named after Janique Etienne, Project Officer with the Fonds Français pour l’Environnement Mondial FFEM, in recognition of the Fund’s support to the IUCN Southwest Indian Ocean project and her interest in the exploration of Walters Shoal.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF640FC12F93DFC6A5705.taxon	description	DESCRIPTION Shell up to 22 mm in height, most specimens up to c. 15 mm, thin, weakly inflated, about equally convex, inequivalve, almost equilateral, weakly prosocline, anterior auricles considerably larger and longer than posterior ones, umbonal angle c. 90 °, colour cream with pale radial or divergent streaks and / or blotches. Left valve sculptured with 9 - 10 unevenly spaced, simple, subobsolete primary radial costae until central part of disc, irregular increase by intercalation of scaly secondary riblets on each side of primary costae, in middle of intercostal space. Interstitial microsculpture of radial scratches in centre of disc, laterally more divergent and / or antimarginal. Anterior auricle strongly ridged and scaly with 6 - 8 radial riblets, interstitial microsculpture granular and / or with irregular scratches. Posterior auricle with 4 - 6 radial riblets with closely spaced scales, interstitial microsculpture with commarginal scratches near disc, more antimarginal near margin. Right valve sculptured as left valve, although more subobsolete with weaker scaled radial riblets. Anterior auricle with 4 radial riblets with close-set lamellae, more prominent near dorsal margin, posterior auricle with four spinous riblets. Byssal notch moderately deep, byssal fasciole broad. Functional ctenolium well-developed, with c. six teeth. Dimensions: Holotype, height 15.0 mm, width 13.6 mm, convexity 4.0 mm.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B254FF640FC12F93DFC6A5705.taxon	discussion	REMARKS The most similar congeneric species is Talochlamys pulleineana (Tate, 1887) from upper bathyal depths off southern Australia (Raines & Poppe 2006: 288). Talochlamys janiqueae n. sp. mainly differs morphologically from T. pulleineana in having a more prominent smooth shell disc in early growth stages, up to c. 4 mm in shell height (T. pulleineana up to c. 1 mm), in having simple, less scaly primary radial riblets, subobsolete towards the centre shell disc (T. pulleineana already scaly in early growth stages), in having closer set lamellae on the primary and secondary radial riblets near the ventral margin (T. pulleineana more prominently spinose). The similarly shaped, sized and brightly coloured congener Talochlamys humilis (G. B. Sowerby III, 1904) from deep water off South Africa (Dijkstra & Kilburn 2001: 298), has a different intercostal microsculpture of commarginal lamellae (T. janiqueae n. sp. has radial and antimarginal scratches). Talochlamys janiqueae n. sp. also has fewer primary radial riblets (c. 30, T. humilis c. 55 - 70). Moreover, T. janiqueae n. sp. has numerous secondary radial riblets (T. humilis only a few) and its radial ribs are scalier (T. humilis has subobsolete or weak squamae). Talochlamys multicolor (Melvill & Standen, 1907) endemic to Gough Island (southern Atlantic) also resembles the present species in size, shape and colour. However, T. janiqueae n. sp. differs morphologically in having weaker primary radial ribs on the left valve (prominent on T. multicolor), in lacking secondary intercostal riblets in early growth stages, having one or two in late ontogeny (T. multicolor 1 - 2 in early, 4 - 5 prominent and scaly in adult), in having wider irregularly spaced radial riblets on the right valve (T. multicolor more closely spaced), in having 6 squamose radial riblets on the anterior auricle of the left valve (T. multicolor has 8 nodulose radial riblets).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2548F640FC5FFA91FA1C55C0.taxon	discussion	REMARK Another species similar to Talochlamys. janiqueae n. sp. is is Talochlamys jousseaumei (Bavay, 1904), from upper bathyal depths in the Sea of Japan, East China Sea and South China Sea (Raines & Poppe 2006: 252, as Veprichlamys jousseaumei). In earlier literature, this species was placed in the genus Veprichlamys Iredale, 1929, but most morphological characters (e. g. shell shape: circular, and sculpture: numerous secondary radial riblets) are correlated with Talochlamys. Talochlamys janiqueae n. sp. differs from T. jousseaumei in having more closely and irregularly spaced primary radial riblets (T. janiqueae n. sp. c. 30, T. jousseaumei regularly and more widely spaced, c. 20), and in having more numerous secondary intercostal radial riblets (T. jousseaumei only a few laterally).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F641FF70FA71FB905786.taxon	description	(Fig. 8 E, F)	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F641FF70FA71FB905786.taxon	materials_examined	TYPE LOCALITY. — Sulu Archipelago, Philippines, 6 ° 08 ’ N, 121 ° 19 ’ E, depth 275 m. MATERIAL EXAMINED. — Walters Shoal – slopes • 1 rv, 1 lv; 33 ° 10 ’ S, 43 ° 49 ’ E; depth 217 - 256 m; 1. V. 2017; Stn DW 4877; MNHNIM- 2017 - 3516 • 1 rv, 1 lv; 33 ° 09 ’ S, 43 ° 50 ’ E; depth 221 - 256 m; 1. V. 2017; Stn DW 4878; MNHN-IM- 2017 - 3520 • 1 pr; 33 ° 17 ’ S, 43 ° 51 ’ E; depth 275 - 318 m; 1. V. 2017; Stn DW 4880; MNHNIM- 2013 - 67058 • 1 rv; 33 ° 17 ’ S, 43 ° 51 ’ E; depth 275 - 318 m; 1. V. 2017; Stn DW 4880; MNHN-IM- 2017 - 3519 • 1 fragment lv; 33 ° 17 ’ S, 43 ° 55 ’ E; depth 272 - 380 m; 3. V. 2017; Stn DW 4885; MNHN-IM- 2017 - 3521 • 1 rv; 33 ° 10 ’ S, 43 ° 57 ’ E; depth 299 - 311 m; 3. V. 2017; Stn DW 4888; MNHN-IM- 2017 - 3517 • 1 rv, 1 lv; 33 ° 09 ’ S, 43 ° 49 ’ E; depth 238 - 283 m; 5. V. 2017; Stn DW 4895; MNHN-IM- 2017 - 3518.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F641FF70FA71FB905786.taxon	distribution	DISTRIBUTION. — Known throughout the western, south-western and central Pacific and western Indian Ocean, here extended to the south-western Indian Ocean. Walters Shoal samples collected on the slopes of the seamount, depth 217 - 380 m.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F641FF70FA71FB905786.taxon	discussion	REMARK This species was collected only dead on the slopes of Walters Shoal. Its occurrence there is not surprising, given its wide Indo-Pacific distribution.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F641FF74FB76FE8E5761.taxon	type_taxon	TYPE SPECIES. — Cryptopecten alli Dall, Bartsch & Rehder, 1938	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F641FC7DFA11FB94548B.taxon	type_taxon	TYPE SPECIES. — Ostrea maxima Linnaeus, 1758 subsequent designation (Schmidt 1818: 67).	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F642FC40F910FE8B55C0.taxon	description	(Fig. 8 A-D)	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F642FC40F910FE8B55C0.taxon	materials_examined	TYPE LOCALITY. — False Bay, South Africa, depth 40 m (designated by Dijkstra & Kilburn 2001: 286) MATERIAL EXAMINED. — Walters Shoal – Slopes • 1 lv; 33 ° 09 ’ S, 44 ° 01 ’ E; depth 647 - 672 m; 6. V. 2017; Stn CP 4901; MNHNIM- 2017 - 3524 • 2 lv, 2 rv; 33 ° 11 ’ S, 44 ° 01 ’ E; depth 620 - 642 m; 7. V. 2017; Stn CP 4903; MNHN-IM- 2017 - 3523.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
FF361D1B2549F642FC40F910FE8B55C0.taxon	discussion	REMARKS To date, this species has been recorded only from the inner continental shelf off South Africa, living at sublittoral depths (30 - 70 m) (Dijkstra & Kilburn 2001). Its occurrence at bathyal depths off Walters Shoal is thus surprising. The dozen samples collected, primarily by brushing and suction methods on the summit plateau of the seamount, did not contain any P. sulcicostatus specimens or even fragments thereof, nor any other Pectinidae. Nonetheless, it is possible that the species occurs there in low numbers that escaped detection. Stochastic colonisation of the shoal may perhaps occasionally occur by means of larvae transported from southern Africa via the Agulhas Return Current, sporadic northward flowing eddies of which flow in the vicinity of the shoal (Lutjeharms & Ansorge 2001). All five shells were rather old and encrusted juvenile valves (Fig. 9 A-D) and were most likely transported from shallower water by post-mortem downslope translocation. We do not believe it likely that they represent net debris contamination from fishing vessels.	en	Dijkstra, Henk H., Ghys, Arne, Maestrati, Philippe (2026): The Pectinoidea (Bivalvia, Propeamussiidae and Pectinidae) of Walters Shoal, with descriptions of six new species. Zoosystema 48 (15): 373-387, DOI: 10.5252/zoosystema-2026v48a15
