New developments in vertebrate cytotaxonomy V. Cytotaxonomy of lampreys

✍ Scribed by I. C. Potter; E. S. Robinson

• Publisher: Springer Netherlands
• Year: 1981
• Tongue: English
• Weight: 155 KB
• Volume: 56
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00055414

✦ Synopsis

Few papers on the chromosomes of cyclostomes have been published since our last review (Potter & Robinson, 1973), and subsequent work has concentrated on those of the lampreys (Petromyzoniformes) rather than the hagfishes (Myxiniformes). This brief account provides a summary of recent information and its bearing on taxonomy and karyotype relationships within the Petromyzoniformes.

The lampreys have an antitropical distribution and are currently separated into three families (Hubbs & Potter, 1971; Potter, in press). The Petromyzonidae includes all the Northern Hemisphere lampreys (several genera and 35 described species), while the Mordaciidae (three species of Mordacia) and Geotriidae (one species of Geotria) are restricted to the Southern Hemisphere. Although early work on petromyzonid chromosomes suggested that the diploid number might range from 60-156, the use of air-dried preparative techniques in the years immediately prior to 1973, indicated that the holarctic lampreys have relatively consistent and very high chromosome numbers (Potter & Robinson, 1973). Using these methods, modal values of 164 were obtained for two North