CRESSEY ET AL.: COPEPODS AND SCOMBRID FISHES 



CD 



co 

 "O 



CD 

 CO 



O 



o 



to 

 3 

 C 

 :», 



o 



o 

 TO 

 E 

 E 



CD 



<3 



a 

 o 



c 



o 



3 

 C 

 C 



-C 



3 

 C 

 C 

 3 

 -C 

 ^- 



i2 x 



3 



FIGURE 17. — Wagner tree of scombrid hosts basedon infestation by 

 copepod species. Synapomorphies (gain, loss, or reduction in infes- 

 tation rate of copepod species) occurred at the following nodes: 

 1) loss of Lernanthropus kanagurta, Orbitacolax aculeatus, andNo- 

 thobomolochus kanagurta; 2) loss of Pumiliopes jonesi; 3) gain of 

 Caligus asymmetricus and Unicolax collateralis; 4) gain of Caligus 

 bonito; 5) gain of Caligus productus and C. coryphaenae; 6) gain of 

 Brachiella thynni; 7) gain of Shiinoa occlusa and reduction of infesta- 

 tion of Caligus productus; 8) reduction of infestation of Caligus asym- 

 metricus; 9) gain of Caligus pelamydis, Unicolax mycterobius, U. 

 collateralis, and reduction of infestation of C. productus and C. cory- 

 phaenae; 1 0) gain of Caligus bonito, Ceratocolax euthynni, and reduc- 

 tion of infestation of Unicolax mycterobius. 



Bomolochus. The eight characters used are as fol- 

 lows: Number of setae on the exopod of leg 4 (many = 

 plesiomorphic, few = apomorphic); presence or ab- 

 sence of surface ornamentation on the abdomen and 

 caudal rami (presence = plesiomorphic, absence = 

 apomorphic); first exopod segment of leg 2 with long 

 hairs or short spinules (hairs = plesiomorphic, spi- 

 nules = apomorphic); number of setae on the first 

 maxilla (4 = plesiomorphic, 3 = apomorphic); num- 

 ber of setae on exopod last segment of leg 2 (5 = 

 plesiomorphic, 4 = apomorphic); number of seg- 

 ments in first antenna (7 = plesiomorphic, 6 = apo- 

 morphic) ; endopod segments with a row of short hairs 

 (plesiomorphic) or patch of fine spinules (apomor- 

 phic); exopod spines of leg 2 with fine hairs (plesio- 

 morphic) or mostly toothed (apomorphic). 



Phylogenetic relationships of the copepod para- 

 sites of the genus Unicolax are represented in the 

 branching diagram (Fig. 19), generated with the 





CO 

 CD 



cc 



CO 



3 

 C 

 C 

 3 

 -C 



FIGURE 18. — Wagner tree of scombrid hosts based on infestation by 

 copepod genera. Synapomorphies (gain or loss of copepod genera) 

 occurred at the following nodes: 1) Orbitocolax, Nothobomolochus, 

 andLernanthropus; 2) loss of Pumilopes; 3) gain of Shiinoa; 4) gain of 

 Caligus; 5) gain of Tuxophorus; 6) gain of Unicolax; 7) gain of Cera- 

 tocolax and Caligus; 8) gain of Pseudocycnoides; 9) loss of Cerato- 

 colax. Autapomorphies are A) gain of Clavellisa; B) gain of 

 Elytrophora; C) gain olHomobomolochus, Unicolax, and Pseudocyc- 

 noides; D) loss of Unicolax and gain of Elytrophora. 



3 



.CO 







3 

 O 



| 



o 



c 



CD 



co 

 .3 

 -Q 

 O 



co 



CO 



3 

 to 



"§ 

 cb 



u 



FIGURE 19.— Cladogram showing relationships of Unicolax species. 

 The nodes (1-4) represent the following: 1 = species of Unicolax; 2 

 = teeth on leg 2 exopod spines; 3 = endopod segments with patches 

 of spinules; 4 = fewer than 5 setae on fourth leg exopod. 



WAGNER 78 program using characters of copepod 

 morphology. The additive binary matrix of this tree is 

 presented in Figure 20. Phylogenetic relationships of 

 the scombrid hosts (Fig. 2 1) are adapted from Collette 

 and Russo (1979) and represent a monophyletic sub- 



255 



