Myrtina reflexa, Taylor, John D. & Glover, Emily A., 2013

Taylor, John D. & Glover, Emily A., 2013, New lucinid bivalves from shallow and deeper water of the Indian and West Pacific Oceans (Mollusca, Bivalvia, Lucinidae), ZooKeys 326, pp. 69-90: 80-81

publication ID

http://dx.doi.org/10.3897/zookeys.326.5786

publication LSID

lsid:zoobank.org:pub:A99E90D4-41F3-419A-9081-0AE370D09CD5

persistent identifier

http://treatment.plazi.org/id/C5254102-0F66-41A0-9A3E-8DB483BB7D44

taxon LSID

lsid:zoobank.org:act:C5254102-0F66-41A0-9A3E-8DB483BB7D44

treatment provided by

ZooKeys by Pensoft

scientific name

Myrtina reflexa
status

sp. n.

Myrtina reflexa   sp. n. Figs 9B, 11

Lucina inanis   ( Prashad 1932) - Knudsen 1967: 286, pl. 2 figs 9,11. (non Prashad 1932).

Lucina inanis   ' Prashad’ - Cosel and Bouchet 2008: 188, figs 55 A–F.

Type material.

Holotype: 1 whole shell, L 10.5 mm, H 9.4 mm, T 2.5 mm, NHMUK 1968738, John Murray Expedition stn 125, 825m, 5°36'12"S, 39°28'24"E off Zanzibar.

Paratypes: 2 RV, L 10.7 mm H 9.5 mm T 2.5 mm, L 11.8 mm H 10.7 mm T 2.8 mm, NHMUK 1968738 locality as holotype; 17 valves (13 RV, 4 LV), figured paratype (Fig. 11E-F) RV, L 15 mm, H 13.3 mm, NHMUK 20130121, John Murray Expedition stn 106, 183-194 m, 5°38'54"S, 39°18'42"E, off Zanzibar.

Other material.

1 whole shell (live collected) L 14.2 mm, H 12.7 mm, T 3.3 mm, MNHN IM 2009-8733, MIRIKY stn DW3239 14°30'S, 47°26'E, 230-288 m, off NW Madagascar.

Description.

Shells greyish white, H to 13.5 mm, L to 15.2 mm, T 3.8 mm, longer than high H/L = 0.91 ± 0.038 (n=8), T/L = 0.24 ± 0.018 (n=8), subovate, posterior truncate, anterior dorsal area marked by shallow double sulcus, anterior dorsal margin with elevated lamellae, umbones low, sculpture of widely spaced commarginal lamellae that are reflected ventrally, no radial sculpture. Microsculpture of fine growth increments (Fig. 11L). Lunule lanceolate, strongly asymmetric with larger part in LV. Protoconch (Fig. 11M): PI+ PII 183 µm, PII a narrow rim. Hinge (Figs 11J, K): LV with 1 thin cardinal tooth, laterals absent, RV with small, single, cardinal tooth, small anterior lateral tooth, posterior lateral teeth absent. Anterior adductor scar short, detached from pallial line for ¼ of length, posterior scar ovoid. Pallial line discontinuous in short narrow blocks. Shell interior glossy, shell margin smooth.

Distribution.

Western Indian Ocean, off Zanzibar and Madagascar from 200-825 m (Fig. 4).

Etymology.

Latin reflexa means bent or turned back, a reference to the form of the commarginal lamellae. Adjective nominative singular

Remarks.

This species was referred to Lucina inanis   (Prashad) by Knudsen (1967) and the same specimens were figured and briefly discussed by Bouchet and Cosel (2008) who thought they more closely resembled species of Alucinoma   . The type and other material of Lucina inanis   from Indonesia and Philippines differ in shape and lack the regular, reflexed commarginal lamellae ( Glover and Taylor in press). Characters of the new species suggest a placement in Myrtina   and this position is corroborated by molecular evidence that places Myrtina reflexa   in the subfamily Leucosphaerinae   close to species UGS -1(now recognised as a new Myrtina   species) from the Philippines ( Taylor et al. 2011). Myrtina   occur in offshore habitats from 30-1200 m from the Philippines and New Caledonia and are likely present in organically enriched sediments throughout the tropical Indo-West Pacific.

Myrtina reflexa   differs from the genotype, Myrtina porcata   , by the more widely spaced and reflexed commarginal lamellae. It is most similar to a new Myrtina   species ( Glover and Taylor in press) from 200-1200 m around the Philippines but is larger and has more prominent and reflexed commarginal lamellae.

Kingdom

Animalia

Phylum

Mollusca

Class

Bivalvia

Order

Lucinoida

Family

Lucinidae

Genus

Myrtina