Table 7. — Needlefish infeslalion by different numbers of 

 copepod species as related to number of specimens exam- 

 ined and maximum host size (in mm. body length) 



ords) ; Caligodcx and L. fylomiri (36) ; P. hellones 

 and L. tylosuri (26) ; L. tylosuri and Colobomatus 

 (25) ; and CaUgodes and Colobomatus (22). The 

 three species of needlefishes most involved in these 

 combinations are the three large worldwide spe- 

 cies: Ablennes Mans, Tylosurus cums, and T. croc- 

 odile. They account for almost all the (7(di- 

 godes-L. tylosuri., C aligodes-C olobomatus, and 

 L. tylosuri-C olobomatus combinations (76 of 83 

 records). T. crocodilus and Ablennes are also im- 

 portant in the P. bellones-C olobomatus and P. 

 belhnes-L. tylosuri combinations (27 records) but 



three species of Strongylura are also involved : S. 

 t/mucu (16 records) aiid/S'. twtatu (6) in the form- 

 er combination and S. ana-stomella (10) in the 

 latter. 



All the common combinations mentioned above 

 (212 of 308 records) involve copepods living in 

 different ecological niches on their host needle- 

 fishes: CaJigodes under the oral valves, Colobo- 

 matus in the cephalic lateral line canals, 

 Lertwnthroints attached to the gill filaments, and 

 Parabomolochus belhnes moving about imder the 

 opercles and in the mouth, especially under the 

 oral valves. No hosts had both L. bel-ones and L. 

 tylosuri. which occupy the same niche, although 

 some host species may have both species of Leman- 

 thropu.'i on different individuals (se^ Host Specific- 

 ity). Tlie habitat of P. beJloives includes the oral 

 valves to which CaUgodes is restricted. We found 

 12 P. bellones-C aligod^s combinations on four 

 species of needlefishes, mostly on Ablennes (8 rec- 

 ords). Four of these Ablennes were large Gulf of 

 (xuinea specimens (418-530 mm. BL) with four 

 or five species of copepods. 



The absence or rarity of some copepod combi- 

 nations is due partly to the influence of host spec- 

 ificity (or host ecology). Thus, there are no 

 CaJigodes laciniaius-Lernanthropus belones com- 

 binations because CaUgodes is restricted to Ablen- 

 nes, Tyloswrus., and a few species of Strongylura, 

 whereas L. belones is found primarily on a differ- 

 ent group of Strongylura. 



The absence of some other combinations is 

 purely geographic : the eastern Pacific Parabomo- 

 lochus constri<;tu^ and P. ensiculus cannot be 



Table 8. — Infestation of needlefishes by more than one species of marine copepod. Upper right half of table gives total number 

 of individual needlefishes with a particular combination of copepods. Lower left half of table gives number of species of 

 needlefish with the particular combination of copepods 



COPEPODS AND NEEDLEFISHES 

 373-320 0—70 11 



427 



