Karyotype of 27 species of eight archaeogastropod families were investigated. Including these results, karyological information on the Archaeogastropoda was reviewed based on the data stored in CISMOCH (Computerized Index System for Molluscan Chromosomes). Conservation in chromosome number and morphology has been urged and was confirmed in major archaeogastropod groups: Patellacea (Acmaeidae and Patellidae), Neritacea (marine neritids) and Trochacea (Trochidae, Turbinidae and Stomatellidae).

more »

... se archaeogastropods have certain characteristic karyotypes including chromosome number, size and morphology. Remarkable diversification in karyotype has occurred primarily in special groups having a secondary limpet-form or expanding from the sea to brackish/fresh-water areas. No results have been obtained in support of the hypotheses on an evolutionary tendency of change in chromosome number, while evolutionary polyploidy is hypothesized to have occurred in a hermaphroditic ancestor at a very early stage of gastropod radiation. CHROMOSOMES OF ARCHAEOGASTROPODA 1':) (.J1 0