Tag Archives: Amastra cyclostoma

Amastra cyclostoma Baldwin

Circle-mouthed Amastra Snail (Amastra cyclostoma)  

This species was described in 1895 when it was already restricted to a tiny relict population inhabiting an area of only about 10 m².  

Charles M. Cooke Jr., an American malacologist who described many endemic Hawaiian gastropod taxa, wrote at 11. April 1899.:  

… It has been found in only one place, under a few orange trees. A circle with radius of six feet [ca. 1,8 m] would enclose the whole space in which they have been found.”  


The Circle-mouthed Amastra Snail was endemic to the coastal regions of Kaumakani [formerly known as Makaweli] at the southwestern coast of Kaua’i, Hawaiian Islands.  

The species’ author made some remarks concerning the animal in life.:  

Animal when extended in motion .95 inches [ca. 2,4 cm] in length; posterior portion of foot tapering and very short, front portion long; head elongated, ocular and labial tentacles widely separated. Mantle dingy-white with streaks of black. Foot very light brown, superior portion and sides thickly studded with regular, dark brown granulations. Tentacles long, dark brown.”  

The shell reached a size of about 1,68 cm.  



[1] David A. Burney; Helen F. James; Lida Pigott Burney; Storrs L. Olson; William Kikuchi; Warren L. Wagner; Mara Burney; Deirdre McCloskey; Delores Kikuchi, Frederick V. Grady, Reginald Gage II; Robert Nishek: Fossil evidence for a diverse biota from Kaua’i and its transformation since human arrival. Ecological Monographs 7(14): 615-641. 2001  


Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second series: Pulmonata. Vol 21: Achatinellidae (Amastrinae). 1911′  

(public domain)


edited: 30.09.2017