P BELIONES 



S limutu 

 S. nolata 



T 



T crocodilus 

 A. hions 

 P argolui 

 L gavialoid»i 

 S onoslomcllo 

 S ineiso 



P SINENSIS 



S itrongyluro 



P CONSTRICTUS 



P. orgolus 

 I. ocui 

 A. Kions 



P ENSICULUS 



S. e<ili< 



5. scopuiori 



N . 50 

 N = 41 

 N- 26 

 N • 36 

 N • 23 

 N • 4 

 N • 9 

 N  33 

 N • 21 

 N- 9 



N. 18 

 N- 9 

 N= 9 



N- 5 

 N- IS 



rin 



I^L. 



FiQUBE 189. — Lengths of two setae on leg 5 of the species of Parabomolochus by hosts. Symbols as in figure 187. 



length for absolute length. For each species of 

 needlefish infested with a given species of copepod, 

 three mean body lengths were compared : mean 

 body lengtli of all specimens examined, mean body 

 length of all specimens that lacked copepods, and 

 mean body length of all specimens infested witli 

 the particular copepod. The least mean body lengtli 

 was ranked 1, the next 2, and the greatest 3- 



The specialized copepods (table 6) show con- 

 sistent results. Without exception, the needlefishes 

 without a specific copepod had the smallest mean 

 body length (1) and the needlefishes with a par- 

 ticular species of specialized copepod had the 

 largest mean body length (3). The mean body 

 lengtli of the total specimens examined was inter- 

 mediate (2). We interpret this sequence to mean 

 that these four specialized species of copepods are 

 attached to needlefishes of larger than average 

 size because of needing sufficient space and time to 

 become attached. 



The generalized copepods show a different pic- 

 ture. As with tlie specialized copepods, three spe- 

 cies {Pai'ahoinolochtts constrictus, P. ensiciilus, and 



Nothoiomolochus gibber) are usually found on 

 needlefishes with greater mean body lengths than 

 the needlefishes with no copepods. Summing the 

 ranks for each of these three species of copepods, 

 however, shows that the mean body lengtlis of 

 needlefish infested with one of these copepods is 

 about equal to the mean body lengths of the total 

 number of needlefishes examined. Thus, the dis- 

 tribution of these three copepods is unrelated to 

 the size of the needlefishes. 



Unlike the situation with the seven species of 

 coj>epods previously discussed, the mean body 

 length of specimens infested with Parabomolochus 

 bellones is equal to or less than the mean body 

 lengths of all specimens examined. This fact seems 

 to indicate that P. bellones selects smaller speci- 

 mens of needlefishes to infest. 



The above analysis confirms the subjective im- 

 pressions that Collette gained while collecting 

 copepods from preserved needlefishes : bomolochids 

 more frequently infest smaller needlefishes than 

 do the specialized copepods. Also, the chance of 

 finding an individual needlefish infested with one 



COPEPODS AND NEEDLEFISHES 



425 



