This article proposes that Cristispira pectinis Gross 1910 be recognized as the type species of the genus Cristispira, a group of spiral-shaped bacteria (spirochetes) found in mollusks. The author reviews the taxonomic history of these organisms, which were initially identified in oysters by Certes in 1882 as a protozoan. Gross established the genus Cristispira in 1910 by describing two species: C. pectinis and C. interrogationis, but did not designate a type species. Subsequently, Winslow et al. (1917) incorrectly designated C. balbianii as the type, and Buchanan (1918, 1925) mistakenly listed C. veneris. The author argues that C. pectinis should be the type species because it was the first species Gross described, its morphology is representative of most other molluscan spirochetes, and C. interrogationis may be a species inquirenda (its status uncertain) due to its smaller size, hooked ends, and resemblance to treponemes. The proposal requests validation from the Judicial Commission of the International Committee on Nomenclature of Bacteria to formally establish C. pectinis as the nomenclatural type of genus Cristispira according to the International Code of Nomenclature of Bacteria.

Key findings

• Cristispira pectinis Gross 1910 is proposed as the correct type species of genus Cristispira, correcting prior erroneous designations by Winslow et al. and Buchanan
• C. pectinis was the first species described by Gross and has morphology representative of most other molluscan spirochetes
• C. interrogationis cannot serve as type species as it may be species inquirenda with atypical morphology resembling treponemes
• Historical nomenclatural errors occurred: C. balbianii was incorrectly selected as type, and C. veneris was mistakenly attributed to Gross
• The designation aligns with the International Code of Nomenclature of Bacteria (1966) requiring type species selection from those originally included in the genus