Chlidonophora Dall, 1903

Bitner, Maria Aleksandra & Logan, Alan, 2016, Recent Brachiopoda from the Mozambique-Madagascar area, western Indian Ocean, Zoosystema 38 (1), pp. 5-41 : 16

Genus Chlidonophora Dall, 1903

TYPE SPECIES. — Terebratulina incerta Davidson, 1878 , by original designation of Dall (1903: 1538).

Chlidonophora chuni Blochmann in Chun, 1900 ( Fig. 9 ; Table 8)

Chlidonophora chuni Blochmann in Chun, 1900: 404, 405; Blochmann 1906: 695-696. — Helmcke 1940: 239, fig. 6. — Muir- Wood 1959: 296, pl. 4, figs 5-7. — Cooper 1973a: 13, pl. 8, figs 17-26. — Hiller 1986: 121-123, fig. 11A-H. — Zezina 1981b: 157; 1985: 133; 1987: 555, 556; 2010: 1187.

MATERIAL EXAMINED. — Mozambique Channel. MAINBAZA, stn CP 3145, 12 bivalved specimens, 1 dorsal valve. — Stn CP 3146, 1 bivalved specimen. — Stn CC 3157, 10 bivalved specimens, 1 ventral valve, 3 dorsal valves. — Stn CC 3158, 1 bivalved specimen.

DEPTH RANGE. — 1161-1421 m.

MEASUREMENTS. — See Table 8.

REMARKS

Only two Recent species are known of this genus. Chlidonophora chuni is restricted to the Indian Ocean while C. incerta is from the Atlantic Ocean and Caribbean ( Logan 2007). Muir-Wood (1959: pl. 4, figs 6-7) figured the lophophore but not the loop of C. chuni from Minikoi, surmising it to be similar to that of C. incerta , which she also figured for comparison (her pl. 3, fig. 8). Cooper (1973a: 13), on the other hand, maintained that the loop of C. chuni “contrasts strongly” with that of C. incerta . He illustrated one of Blochmann’s specimens of C. chuni (USNM 110436a) from off the Maldives to show the loop. However, the crural processes in that particular specimen are barely discernible (his pl. 8, fig. 26), whereas in the specimens from Madagascar they can be prominent, pointed and strongly converging, although they do not unite (compare Fig. 9 G-J and Fig. 9K, L ). Hiller’s description (1986) of the loop of C. chuni from eastern South Africa is much more in agreement with that seen from Madagascar, although his fig. 11F is similar to Cooper’s. Relative measurements suggest that these differences are not a function of growth stages.

Figures

FIG. 9. — Chlidonophora chuni Blochmann,1900,Mozambique Channel,Bazaruto transect,MAINBAZA:A, B, dorsal view of complete specimen (MNHN IB-2013- 55), and enlargement of the umbonal part (B) to show details of the beak, stn CC 3158, 1220-1248 m; C, D, inner view of dorsal valve (MNHN IB-2013-56) with preserved subplectolophous lophophore, (D) enlargement of lophophore, stn CC 3157, 1410-1416 m; E, F, inner view of ventral valve (MNHN IB-2013-57) and enlargement of umbonal part (F), stn CC 3157; G-J, inner and oblique views of dorsal valve (MNHN IB-2013-58), enlargement (I) and tilted view (J) of posterior part to show cardinalia and loop, stn CC 3157; K, L, inner and tilted views of posterior part of dorsal valve (MNHN IB-2013-59), stn CC 3157. All SEMs. Scale bars: A, C, E, G, H, 2 mm; B, F, D, I-L, 1 mm.