Protapes ziczac (Linnaeus, 1758)

Arathi, Anitha R., Oliver, P. Graham, Ravinesh, Raveendhiran & Kumar, Appukuttannair Biju, 2018, The Ashtamudi Lake short-neck clam: re-assigned to the genus Marcia H. Adams & A. Adams, 1857 (Bivalvia, Veneridae), ZooKeys 799, pp. 1-20 : 12-14

Protapes ziczac (Linnaeus, 1758) Figure 11

Original combination.

Venus ziczac Linnaeus, 1758

Synonyms.

(from MolluscaBase 2018d) Venus sinuosa Lamarck, 1818; Tapes inflata Römer, 1870

Type locality.

Linnaeus (1758) gives the type locality as the Indian Ocean.

Material examined.

Neendakara, Kollam, 5 live collected specimens + 18 empty articulated shells; Dharmadam, Kannur, 3 live collected specimens.

Description.

Shells to 50 mm, solid, inflated, equivalve, inequilateral, beaks slightly in front of midline. Outline sub-ovate, lunule margin impressed, anterior margin pronounced, posterior ventral margin subtruncate, posterior area strongly sinuous. Lunule lanceolate, weakly ridged. Escutcheon narrow, smooth. Sculpture of raised concentric ridges separated by nearly equal-sized grooves. Pallial sinus narrow, apex rounded, ascending steeply towards umbonal cavity. Shell external colour tan with bright zigzag streaks and four brown rays radiating from umbo to ventral margin. Shell interior colour white with yellowish tinge in umbonal cavity.

Distribution.

The species has an Indian Ocean distribution with records from the Red Sea, Aden, East Africa, Somalia, Mozambique, Maputo, Inhambane, Nacala, Natal, Madagascar, Oman, and Persian Gulf ( Huber 2010).

Remarks.

Protapes ziczac (Linnaeus, 1758) has an inflated, heavy, and solid shell with the external sculpture the strongest of any species of Protapes .

The species was recorded as Protapes sinuosa (Lamarck 1819) by Oliver and Glover (1996) from the Arabian Sea, but has subsequently been shown to be Protapes ziczac (Huber, 2010). Huber (2010) gave P. sinuosa as a junior synonym and also synonymised Tapes inflata Römer, 1870 with P. ziczac , but Huber (2010) doubted the locality given as Sri Lanka. He regarded the Indo-Pacific shells identified as P. sinuosa as a new taxon, P. swenneni (Huber, 2010).