Friday, April 19, 2024

[Mollusca • 2023] Meretrix taiwanica (Bivalvia: Veneridae) • a previously misidentified New Species in Taiwan


Meretrix taiwanica 
Hsiao & Chuang, 2023


ABSTRACT
This paper describes a new Asian hard clamMeretrix taiwanica sp. n., found in the Tamsui River estuary in northern Taiwan. This species was formerly identified as M. lusoria, and was considered to be a descendant of a clam that originated in Japan. A molecular phylogenetic analysis, however, demonstrated that Meretrix taiwanica sp. n. is closely related to M. petechialis and M. lusoria. Meretrix taiwanica is distinguished by its smaller socket width and shorter posterior dorsal margin. This species is distributed throughout the coast of Taiwan on the southern coast of China.

KEYWORDS: Asian hard clams, COI-DNA barcoding, Meretrix lusoria, Meretrix petechialis, Tamsui River

  Colour patterns of Meretrix taiwanica sp. n., FRIM10031.

  Shells of hard clams A, Meretrix taiwanica sp. n.; B, M. petechialis; C, M. lusoria; D, Cytheraea formosa (unavailable name-bearing types, syntype, digital image cited from BMNH HP collection, 20120227).

Systematics
Superfamily Veneroidea Rafinesque, 1815
Family Veneridae Rafinesque, 1815

Genus Meretrix Lamarck, 1799

Meretrix taiwanica Hsiao & Chuang, sp. n.

Diagnosis: Shell surface of M. lyrata has commarginal ribs; ventral margins of M. taiwanica sp. n., M. lamarckii and M. lusoria smooth, flat and round, respectively. Meretrix taiwanica sp. n. similar in shape to M. lusoria and M. petechialis (Figure 6A–C) but differs in several morphological features. Posterior dorsal margin of M. lusoria relatively straight, causing rear shell angle to be sharper, socket narrower. Shell-shaped posterior margin of M. petechialis rounded,with wider socket. Posterior margin of M. taiwanica sp. n. rounded with narrower socket than M. petechialis.

Etymology: We name this species ‘taiwanica’ in reference to the collection locality in Taiwan. Additionally, this species is the most abundant and widely distributed hard clam in Taiwan.


 
Sheng-Tai Hsiao and Shih-Chang Chuang. 2023. Meretrix taiwanica (Bivalvia: Veneridae), a previously misidentified New Species in Taiwan. Molluscan Research. DOI: 10.1080/13235818.2023.2189428