Recent Candoninae (Crustacea, Ostracoda) of North America

WA Museum Records and Supplements | Updated 7 years ago

ABSTRACT – A total of 66 species of Candoninae have been described or recorded from North America in the period between the years 1894 and 1990. The majority of these species are known from the United States of America and their type material is kept in the Smithsonian Museum of Natural History in Washington. Since they were described, many new genera have been established in the subfamily Candoninae and more important morphological features for generic discrimination have been found. The descriptions of the North American Candoninae species are not sufficient to enable a proper generic designation or to establish their relationships with other World representatives of the subfamily. This paper is the result of re-examination of almost the entire collection of North American Candoninae from the Smithsonian Museum, and has resulted in a description of one new species and supplementary descriptions of 23 species. Seventeen species and four subspecies known from North America are synonymized, and four species known from elsewhere are synonymized with some of the North American species. Several species are found to be misidentified and three are considered incerte sedis. As a result of this revision, with the addition of the synonyms already recognized, the number of North American Candoninae is reduced to 40 species. A key for their identification is provided. In addition, a key to the World representatives of the caribbeana-group of species of the genus Typhlocypris Vejdovsky, 1882 is given. The morphological characteristics of some examined species necessitate redefinition of the genera Candona Baird, 1845, Eucandona Daday, 1900 and Fabaeformiscandona Krstic, 1972. In the present paper the genus Candona is divided into two subgenera: Candona s.str. and Neglectocandona Krstic, 1993. The nominal subgenus is further divided into three species groups: candida-, acuminata-, and intermedia-group. Neglectocandona is divided into neglecta- and triangulata-group. The groups intermedia and triangulata are established here for the first time. The former group is endemic to North America, while the latter is endemic to Ohrid Lake. The generic diagnosis of the genera Eucandona and Fabaeformiscandona are narrowed and a discussion on the systematics of all three genera is given. The majority of the North American Candoninae, ie. 47%, belong to the genus Candona, 32% to the genus Typhlocypris, 13% to Eucandona, while Nannocandona Ekman, 1914, Paracandona Hartwig, 1899 and Fabaeformiscandona have one representative each (2.5%) in the North American fauna. Total of 14 species recorded in North America are also known from elsewhere, while 26 species are endemic to this region.