Carelia paradoxa ssp. paradoxa (Pfeiffer)

Paradox Carelia Snail (Carelia paradoxa ssp. paradoxa 

The nominate of this species was described based on fresh, empty shells and subfossil ones, all other races are known from subfossil specimens alone.  

The shells reached lengths of up to 4,5 cm, they are distinctly and closely granulate, blackish brown, the spire is long and forms an acute cone above.  

The species inhabited the near-shore lowlands at the base of the Kalepa Mountains on the southern side of the Wailua river, where it met with a relict population of the Dead Carelia Snail (Carelia necra Newcomb) and formed a hybrid population that was originally described as a distinct subspecies (Carelia paradoxa ssp. thaanumi Cooke).  

This hybrid form was characterized by its embryonic whorl that was similar to that of C. paradoxa, while its adult whorls where identical to those of C. necra. [2]  

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References:  

[1] C. Montague Cooke Jr.: The land snail genus Carelia. Bishop Museum Bulletin 85: 1-97. 1931 [2] Elwood Zimmerman: Insects of Hawaii 1, Introduction. University of Hawaii Press, Honolulu 1947  

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

(public domain) 

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edited: 01.04.2018