Xenostrobus or Vignadula (Bivalvia: Mytilidae)? A taxonomic re-evaluation of small black mussels inhabiting the upper intertidal zone of the estuaries of Southeast Asia Author Tan, Koh Siang Author Tan, Samuel Hui Ming Author Sanpanich, Kitithorn Author Duangdee, Teerapong Author Ambarwati, Reni text Zoological Journal of the Linnean Society 2022 2022-05-14 196 316 345 https://www.mendeley.com/catalogue/f5a3130a-cb03-3121-b8eb-32409c478f89/ journal article 133184 10.1093/zoolinnean/zlac031 fe110920-333b-4cdc-98f2-a4cc24124ea8 0024-4082 7035193 968C576E-4747-4586-9D48-C24C92741905

Table 2. Major morphological traits that differentiate Xenostrobinae from mytilid genera currently placed in the Arcuatulinae (World Register of Marine Species, accessed 16 November 2021)

Trait	Xenostrobinae	Limnoperna	Mytella	Arcuatula
Teeth on inner margin No		No	Yes (anterior end only)	Yes (dorsal and anterior
of valves				margins)
Resilium pits	No	No	Yes	No
Posterior byssal re-	No (Category 2 of Morton, 2015a)	Yes (Category 3)	No (Category 2)	Yes (Category 3)
tractor muscle scars
clearly separated?
Ctenidial attachment	No	Yes (Morton & Dinesen, 2010)	No	No
muscle scars
Position of gut loop	Right of animal (Wilson, 1967; this study)	Left of animal (Kimura et al.,	Left of animal (Tan KS,	Left of animal (pers. obs.)
		1999)	pers. obs.)
Plicate gland (organ of Absent in type species of Xenostrobus		Present (outer) (Thomsen	Absent in Mytella	Absent (Thomsen et al.,
Sabatier)	and Vignadula; present in some species	et al., 2018)	strigata (Hanley,	2018 [as Musculista])
	(this study)		1843) (Tan KS, pers.
			obs.)