Texas lilliput

Toxolasma texasensis (Lea, 1857)

Texas lilliput
Toxolasma texasensis, UIMNH Z-15115. Wabash River, White County, Illinois. Length: 2.2 inches (5.6 cm) for male (top), 1.8 inches (4.6 cm) for female (bottom).

Other common names: None.

Key characters: Small shell, pointed or truncated on the posterior end, and greenish brown or black with a clothlike texture.

Similar species:  Lilliputpurple lilliputlittle spectaclecasepondmussel.

Description: Shell elongate, thin to relatively solid, and moderately inflated. Anterior end rounded, posterior end pointed (males) or truncated (females). Umbos even with or only slightly elevated above the hinge line. Beak sculpture of five or six strong angular ridges. Periostracum greenish brown to black with clothlike texture. Length to 2.5 inches (6.4 cm).

Texas lilliput distribution map 1992

Pseudocardinal teeth relatively thin and compressed, elevated and serrated; two in the left valve, one in the right. Lateral teeth long, straight or curved; two in the left valve, one in the right. Beak cavity shallow. Nacre white, occasionally tinged with salmon in the beak cavity and center of the shell.

Habitat: Small to medium streams or sloughs in mud or sand in slow-flowing water.

Status: Essentially a southern species that is rare in the Midwest.

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