A PRELIMINARY REPORT ON THE OSTRACODA 

 OF THE BENGUELA CURRENT 



By E. J. lies, B.Sc, Ph.D. 

 Department of Zoology, The University of Manchester 



(Text-figs. 1-5) 



INTRODUCTION 



he R.R.S. 'William Scoresby ' carried out two surveys of the Benguela current in 1950, the first 



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in March, and the second in September-October. Some of the results of these surveys have been 

 briefly described by Hart (1953) and Currie (1953), but some time will no doubt be needed for the 

 full analysis of the data, and especially for examination of the collections of plankton. Dr T. J. Hart 

 has carried out the laborious task of sorting the samples of zooplankton, and at the invitation of 

 Dr N. A. Mackintosh I undertook to examine and report upon the Ostracods. The sorting has been 

 so effective that I have received all the material from the first survey, including the early juvenile 

 stages. The present report is based on this material: that is to say it is limited to the first of the two 

 surveys, and at this stage I have thought it best simply to give an account of the species identified, to 

 note the numbers in which they occur in the samples, and to draw attention to certain aspects of their 

 horizontal and vertical distribution. It is hoped that a report on these lines will materially assist a 

 wider study of the fauna of the Benguela current and its relations to the hydrographic features of this 

 interesting region. 



With the exception of a very few species the planktonic Ostracods of the open sea belong to a single 

 family, the Halocypridae. Previous marine expeditions have provided material that has made possible 

 the recognition of what is probably the majority of the existing species of the family. A series of 

 workers (Claus, Brady, Midler, Vavra, Sars, etc.) have worked out these collections but their descrip- 

 tions are mainly limited to a few diagnostic features. More recently Skogsberg (1920, 1946) re- 

 described certain species and drew attention to the inadequate nature of the previous descriptions. 

 Although, as he pointed out, taxonomic revision of the family is clearly needed, re-description of 

 many more species will be necessary before this can be done. However, I have decided that it would 

 be preferable to postpone re-description of the species considered in this report until material with 

 a much wider range of distribution has been examined. The species found in the samples have thus, 

 with one exception, been determined and classified on the basis of existing taxonomic knowledge. 

 They are listed below with the appropriate authorities. The juvenile stages of the Halocypridae have 

 not been adequately described in the literature and therefore the early stages whose identity cannot 

 yet be established have been listed as 'unidentified juveniles'. Numerical data regarding material 

 from the samples are included in the tables, which form an appendix to this report. 



I wish to acknowledge my indebtedness to the National Institute of Oceanography for the 

 opportunity of examining the material. I should also record my sincere thanks to Dr Mackintosh 

 for the trouble he has taken in reading through and checking the typescript, and to Dr Hart for the 

 information he has supplied. Dr J. P. Harding of the British Museum (Natural History) has very 

 kindly given me details of the type material of Halocypris punka Scott. Finally, I wish to thank 

 Prof. H. Graham Cannon for introducing me to the field of study of Ostracod taxonomy and for his 

 continued interest and advice during the progress of my work. 



