the analysis of host-parasite relations and because 

 our material is so abundant. In this paper we pre- 

 sent the results of our survey of the parasitic cope- 

 pods found on the needlefishes (Belonidae). Cres- 

 sey is responsible for the identifications and de- 

 scriptions of the parasitic copepods, and Collette 

 is responsible for the identifications of the hosts 

 and most of the collection data. Both authors are 

 responsible for the interpretations and analysis of 

 data. 



We believe a host specialist and a parasite spe- 

 cialist must work together to answer the questions 

 we consider here. Data on host distribution, ecol- 

 ogy, and evolution can then be integrated with 

 parasite data. Only in this way can we solve some 

 of the important problems concerning the biology 

 and evolution of host and parasite. 



We have considered the following questions 

 about needlefishes and their copepod parasites: 



1. To what extent are copepods host-specific? 



2. How do the distributions of hosts and para- 

 sites compare? 



3. Is intraspecific variation in copepods re- 

 lated to host iiifluence, ecology, or 

 geography? 



4. What are the relative rates of evolution of 

 host and parasite? 



5. Do larger host individuals have a greater 

 copepod fauna ? 



6. Is there competition among different spe- 

 cies of parasites on the same hosts? 



7. How do the relative infestations of a given 

 host species by a given copepod species 

 compare in time and space? (We use the 

 word infestation as the appropriate term 

 for an ectoparasite or commensal that is a 

 nonmultiplying invader as opposed to a 

 multiplying one.) 



8. Are the copepods associated with needle- 

 fishes parasitic in the strict sense or are 

 some of them commensal or mutualistic? 



This paper consists of three major parts : first, 

 a taxonomic description of copepods found on 

 needlefishes; second, an account of the copepods 

 we found on each species of needlefish ; and third, 

 a consideration of the questions posed above on 

 the basis of the data presented in the first two 

 sections. 



We have not subjected our data to sophisticated 

 statistical tests for several reasons. The needlefish 

 material available in museum collections is strong- 



ly biased as regards such things as locality, num- 

 ber of specimens, and dates of collection. Then a 

 further bias has been introduced by selecting cer- 

 tain needlefishes to examine. Ideally, one should 

 plan a sampling program for needlefishes in time 

 and space and then subsample the hosts, especially 

 with regard to size. But we have used historic col- 

 lections (or accumulations) so we believe it is pref- 

 erable to present tabular summaries or graphs of 

 what we found and then to try to explain the re- 

 sults. Our use of museum collections of needle- 

 fishes has certainly biased our results in one other 

 respect — because many external forms are not 

 firmly attached we have found far fewer external 

 copepod parasites (such as Caligus) than we 

 would have found on fresh material. 



MATERIALS AND METHODS 



The 28 species of epipelagic fishes composing 

 the needlefish family Belonidae are fomid in fresh 

 waters, estuaries, and marine habitats both inshore 

 and offshore. Four species are worldwide; the 

 other 24 species have more restricted distributions. 

 Needlefishes vary in maximum body length from 

 42 mm. for the two neotenic South American fresh 

 water species of Belonion to 950 mm. for the 

 worldwide Tylosurus acus. Wliile preparing a 

 monograph on the Belonidae, Collette looked for 

 copepods on 2,720 needlefishes from more than 800 

 collections. Copepods were found on all but three 

 species — the rare South African Petalichfhys 

 capensis, of which only a single specimen was 

 examined, and the two species of Belonion. The 

 nomenclature used for the needlefishes in this 

 paper is based on Collette and Berry (1965), 

 Parin (1967), and Collette and Parin (1970). 



The needlefishes examined for copepods are 

 housed in most of the major fish collections in the 

 world. Abbreviations of these collections are listed 

 below. Full data on each host collection are not 

 included in this paper but are available from 

 Collette : 



AMNH: American Museum of Natural History, 

 New York, N.Y. 

 ANSP: Academy of Natiu-al Sciences, Phila- 

 delphia, Pa. 

 BMNH: British Museum (Natural History), 

 London, England 

 BOC: Bingham Oceanographic Collection, 

 Peabody Museum, Yale University, 

 New Haven, Conn. 



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U.S. FISH AND WILDLIFE SERVICE 



