Codakia Scopoli, 1777

Glover, Emily A. & Taylor, John D., 2007, Diversity of chemosymbiotic bivalves on coral reefs: Lucinidae (Mollusca, Bivalvia) of New Caledonia and Lifou, Zoosystema 29 (1), pp. 109-181 : 130-134

Genus Codakia Scopoli, 1777

Codakia Scopoli, 1777: 398 .

Lentillaria Schumacher, 1817: 49 . Type species: Venus punctata Linnaeus, 1758 (monotypy).

Pexocodakia Iredale, 1930: 389 . Type species: Lucina rugifera Reeve, 1850 (original designation).

TYPE SPECIES. — Venus orbicularis Linnaeus, 1758 ( Chama , le codok Adanson, 1757) (by monotypy).

DIAGNOSIS. — Shells robust, medium to large, discoidal, flat to moderately inflated. Sculpture of numerous fine to broad low radial ribs crossed by fine commarginal lamellae, sometimes producing nodules at intersection with radial ribs. Lunule short, triangular to narrowly ovate, deep, strongly asymmetric, projecting from RV. Ligament large, set in deep resilifer. RV with two cardinal teeth, and a single, large anterior lateral tooth set close to cardinal teeth, posterior lateral teeth absent or indistinct. LV with 2 cardinals, anterior lateral 1 or 2, close to cardinal. Posterior lateral tiny or absent. Anterior adductor scar, long, detached from pallial line for about 2/3 of length. Shell usually white, internally with margin and hinge often rose-pink to red, within pallial line shell often yellow.

Codakia paytenorum ( Iredale, 1937) ( Figs 14G, H ; 15A )

Lentillaria paytenorum Iredale, 1937: 240 , 241, pl. 16, figs 2-3.

Codakia (Codakia) paytenorum – Lamprell & Whitehead 1992: pl. 19, fig. 120.

TYPE MATERIAL. — Figured specimen not isolated from shells of L. paytenorum collected by Iredale on Lord Howe Island ( AMS).

TYPE LOCALITY. — Lord Howe Island, Australia.

MATERIAL EXAMINED. — Koumac. 3 stn, 0-12 m, 2 v, 1 live.

Touho. 2 stn, 0 m, 7 v, 1 live.

Lifou. 9 stn, 0-55 m, 16 v.

Chesterfield Islands. CHALCAL/CORAIL 2, recorded from 24 stn at depths from 28- 69 m.

Other New Caledonia. LAGON, stn 161, Île Ouen, Baie du Prony, 22°34’S, 166°38’E, 2 m, 2 v. — Stn 241, 22°21’S, 167°00’E, 35 m, 1 v. — Stn 294, Grand Récif Sud, 22°44’S, 166°42’E, 21 m, 1 sh. — Stn 545, 22°52’S, 166°50’E, 37 m, 1 v. — Stn 772, secteur du Poindimie, 21°08’S, 165°41’E, 30 m, 2 v. — Stn 1139, secteur des Belep, 19°24’S, 163°47’E, 39 m, 1 v. — Stn 1140, 19°24’S, 163°44’E, 44 m, 1 v. — Stn 1156, 19°10’S, 163°13’E, 55 m, 1 v. — Stn 1157, 19°10’S, 163°10’E, 48 m, 2 v. — Stn 1196, 19°33’S, 163°21’E, 30 m, 1 v.

DISTRIBUTION. — Red Sea, Indian Ocean, West Pacific.

DESCRIPTION

Shell solid, medium to large (H to 53 mm, L to 55 mm), subcircular. Sculpture low radial ribs of variable width, narrower at anterior and posterior margins and often sparse in central part of shell. Ribs crossed by numerous fine, sometimes anastomosing, commarginal lamellae. Anterior and posterior dorsal areas raised into finely nodular sculpture. Lunule short, heart-shaped, deeply impressed, strongly asymmetrical. RV with two cardinal teeth and a large anterior lateral very close to cardinals and a vestigial posterior lateral. LV with one cardinal, an anterior lateral close to cardinal, and a low posterior lateral. Anterior adductor scar short, tapering, detached for 1/2 of length. Shell margin smooth, glossy. Colour white, umbonal areas tinged dark pink, interior shell margin deep pink to white, shell within pallial line bright yellow.

REMARKS

Iredale (1937) introduced the name Lentillaria paytenorum for shells with intensely rose-red coloured shell margins from Lord Howe Island and Queensland, distinguishing the new species from the yellow-coloured C. interrupta (Lamarck, 1818) . We have examined a large number of specimens of both the yellow and pink margined “species” from the IWP and have been unable to find any consistent morphological differences to separate them. Preliminary molecular analysis (unpublished data) has revealed differences between the yellow forms similar to C. interrupta and the pink margined C. paytenorum including a sample from the type locality. For this reason we use the name C. paytenorum for the pink-margined New Caledonia samples.

Codakia punctata ( Linnaeus, 1758) ( Figs 14 A-C; 15B)

Venus punctata Linnaeus, 1758: 688 .

Codakia punctata – Mörch 1853: 33.

TYPE MATERIAL. — Not located.

TYPE LOCALITY. — Indian Ocean.

MATERIAL EXAMINED. — Koumac. 4 stn, 0-15 m, 5 v, 6 live.

Touho. 4 stn, 0-2 m, 36 v, 9 live.

Lifou. 15 stn, 0-30 m, 46 v.

Chesterfield Islands. CHALCAL 1, stn DC 17, 19°12’S, 158°56’E, 44 m, 1 v.

CORAIL 2, stn DW 42, 19°22’S, 158°29’E, 45 m, 1 v. — Stn DW 48, 19°18’S, 158°27’E, 44 m, 1 v. — Stn DW 51, 19°19’S, 158°37’E, 69 m, 1 v. — Stn DW 60, 19°15’S, 158°27’E, 45 m, 1 v. — Stn DW 87, 19°06’S, 159°00’E, 31 m, 3 v. — Stn DW 100, 19°06’S, 158°27’E, 40 m, 1 v. — Stn DW 110, 19°09’S, 158°56’E, 40 m, 6 v. — Stn DW 138, 19°34’S, 158°18’E, 31 m, 4 v. — Stn DW 158, 19°46’S, 158°17’E, 28 m, 1 v. — Stn DW 160, 19°46’S, 158°23’E, 35-41 m, 3 v.

Other New Caledonia. LAGON, stn 98, Île Ouen, Baie du Prony, 22°36’S, 166°32’E, 15 m, 1 v. — Stn 478, Lagon Nord, 18°53’S, 163°27’E, 35 m, 2 v. — Stn 479, 18°55’S, 163°28’E, 37 m, 1 sh. — Stn 517, 19°09’S, 163°35’E, 42 m, 1 v. — Stn 544, Grand Récif Sud, 22°51’S, 166°49’E, 25 m, 1 v. — Stn 554, 22°50’S, 166°54’E, 27 m, 1 sh. — Stn 589, Île des Pins, 22°32’S, 167°23’E, 31 m, 1 v. — Stn 1063, secteur de Belep, 20°03’S, 163°47’E, 31 m, 1 v. — Stn 1087, 19°48’S, 163°60’E, 24 m, 1 v. — Stn 1104, 19°42’S, 163°59’E, 22 m, 2 v. — Stn 1105, 19°40’S, 163°57’E, 25 m, 3 v. — Stn 1118, 19°35’S, 163°52’E, 30 m, 3 v. — Stn 1145, 19°21’S, 163°45’E, 38 m, 1 v. — Stn 1158, 19°10’S, 163°07’E, 48 m, 1 v. — Stn 1196, 19°33’S, 163°21’E, 30 m, 1 v.

Loyalty Islands. MUSORSTOM 6, stn DW 430, 20°21’S, 166°07’E, 30 m 1 v. — Stn DW 435, 20°21’S, 166°08’E, 32 m, 1 v.

DISTRIBUTION. — Widely distributed across the IWP from the Red Sea and East Africa to Rapa, SW Pacific.

SHORT DESCRIPTION

Shell medium to large (H to 51 mm, L to 53 mm). Sculpture of around 30-40 broad, low radial ribs, variable in width, crossed by very fine, closely-spaced, commarginal lamellae. Lunule small, narrowly triangular, slightly impressed, right valve protrudes into left. Externally, dorsal areas sometimes dark pink. Interior shell margin deep rose-pink, yellow within pallial line.

Codakia tigerina ( Linnaeus, 1758) ( Figs 14 D-F; 15C)

Venus tigerina Linnaeus, 1758: 688 .

Codakia tigerina – Mörch 1853: 33.

TYPE MATERIAL. — Syntypes ( LSL).

TYPE LOCALITY. — Indian Ocean.

MATERIAL EXAMINED. — Koumac. 5 stn, 0-2 m, 7 v, 3 live.

Touho. 5 stn, 0-10 m, 10 v, 19 live.

Lifou. 7 stn, 0-10 m, 15 v, 9 live.

Other New Caledonia. Île Nou, 2 sh. — Île des Pins, 3 v. — Îlot Maitre, 2 v. — Nouméa, Ouen Toro, 9 sh.

DISTRIBUTION. — Widely distributed across the IWP from the Red Sea and East Africa to Tuamotus.

SHORT DESCRIPTION

Shell medium to large (H to 66 mm, L to 60 mm), subcircular, low umbones.Sculpture finely nodulose, with thin radial ribs crossed by sometimes anastomosing commarginal lamellae, forming rows of nodules at intersections. Lunule short, heart-shaped, deeply impressed into notch. Anterior lateral teeth of both valves lie extremely close to cardinal teeth. Interior shell colour dark rose-pink around shell margins, pale yellow within pallial line.

Figures

FIG. 14 — A-C, Codakia punctata (Linnaeus, 1758), Touho, stn 1242, New Caledonia (MNHN); A, exterior of left valve; B, C, interior of right and left valves; D-F, C. tigerina (Linnaeus,1758), Touho,stn 1242, New Caledonia (MNHN);D, exterior of right valve; E, F, interior of left and right valves; G, H, C. paytenorum (Iredale, 1937), Touho, stn 1245, New Caledonia (MNHN), exterior and interior of right valve. Scale bars: 10 mm.

FIG. 15 — Outline drawings of interiors of right valves of Codakia Scopoli,1777 and Ctena MÖrch,1861 species:A, Codakia paytenorum (Iredale, 1937); B, Codakia punctata (Linnaeus, 1758); C, Codakia tigerina (Linnaeus, 1758); D, Ctena bella (Conrad, 1837). Not to scale.