Pegophysema bialata ( Pilsbry, 1895 )

Jirapatrasilp, Parin, Cuny, Gilles, Kocsis, László, Sutcharit, Chirasak, Ngamnisai, Nom, Charoentitirat, Thasinee, Kumpitak, Satapat & Suraprasit, Kantapon, 2024, Mid-Holocene marine faunas from the Bangkok Clay deposits in Nakhon Nayok, the Central Plain of Thailand, ZooKeys 1202, pp. 1-110 : 1-110

Pegophysema bialata ( Pilsbry, 1895)

Figs 13 E , 15 A

Loripes bialata Pilsbry, 1895: 133 – 134, pl. 3, figs 13, 14. Type locality: Inland Sea, Japan.

Anodontia (? Pegophysema) bialata. Taylor and Glover 2005: 305 – 306, figs 11 a, 12 a, 22, 23.

Pegophysema bialata . Huber 2015: 102, 455 – 456, with in-text figs; C 10244. Wells et al. 2021: 35.

Referred material.

CUF - NKNY - B 11 (3 L + 3 R shells; Figs 13 E , 15 A ).

Habitat.

Muddy bottoms and sandy mud among weed in intertidal zones down to 60 m depth ( Huber 2015).

Distribution.

Indian Ocean; Indo-West Pacific, from Japan to Malaysia ( Taylor and Glover 2005; Huber 2015).

Record in Thailand.

Gulf of Thailand ( Wells et al. 2021).

Taxonomic remarks and comparisons.

This species differs from its similar species, Pegophysema philippiana (Reeve, 1850) , by having a ligament that is shallowly inset and an absence of secondary pallial attachment scars ( Taylor and Glover 2005). See also comprehensive taxonomic remarks in Taylor and Glover (2005).

Order Venerida Gray, 1854

Superfamily Cyrenoidea Gray, 1840

Figures

Figure 13. Size comparison of bivalves and other invertebrates found in this study A Placuna placenta B Standella pellucida C Geloina bengalensis D Anadara inaequivalvis E Pegophysema bialata F Megabalanus cf. tintinnabulum G Cultellus maximus H Lutraria complanata I Thalassina sp. J Tellinides conspicuus.

Figure 15. Bivalves A Pegophysema bialata B Geloina bengalensis C Lutraria complanata D Standella pellucida E Tellinides conspicuus F Joannisiella oblonga.