PHYLOGENY OF ARIETELLID COPEPODS 



171 



Hyperbenthic 



Hyperbenthiclcave 



Hyperbenthic I cave I 

 epipelagic 



Hyperbenthic 



Pelagic 



Pelagic 



Hyperbenthic 



Pelagic 



Hyperbenthic 



Hyperbenthic 



Fig. 45. Habitat cladogram of arietellid genera. Substitution of habitat type of each genus onto cladogram shown in Fig. 44. 



4a Antennary exopod indistinctly 10-segmented; maxillulary prae- 

 coxal arthrite with strongly serrate spines; long innermost seta 

 on fifth endopod segment of maxilliped; outermost seta on sixth 

 endopod segment of maxilliped not reduced; left antennule (cf) 

 with 2 setae on segments II and III, and segments XXI and 

 XXII fused; right endopod of leg 5 (cf) lacking 

 Crassarietellus gen. nov. 



4b Antennary exopod indistinctly 8-segmented; maxillulary prae- 

 coxal arthrite with weakly serrate spines; short innermost seta 

 on fifth endopod segment of maxilliped; outermost seta on sixth 

 endopod segment of maxilliped reduced; left antennule with 1 

 seta on segments II and III, and segments XXI and XXII 

 separate; right endopod of leg 5 (cf ) present 

 Campaneria gen. nov. 



5a Innermost seta on fourth and fifth endopod segments of maxil- 

 liped vestigial Arietellus Giesbrecht, 1892 



5b Innermost seta on fourth and fifth endopod of maxilliped not 

 vestigial 6 



6a Antennary exopod segment X unarmed 



Paraugaptilus Wolfenden, 1904 



6b Antennary exopod segment X with 3 elements 7 



7a Leg 4 with inner coxal seta; second antennary endopod segment 

 with 2 inner setae at midlength .... Paraugaptiloid.es gen. nov. 



7b Leg 4 without inner coxal seta; second antennary endopod 

 segment with 3 inner setae at midlength 8 



8a Antennulary segments XXV and XXVI separated; basal spine 

 of maxilla ornamented with spinules; outermost seta on sixth 

 endopod segment of maxilliped vestigial; genital double-somite 

 (9) with copulatory pore located midventrally on median line or 

 on left side; copulatory duct heavily chitinized; seminal recep- 

 tacle elongate, its distal end bulbous in shape; inner process 



(derived from endopod) of leg 5 (9) with 4 setae 

 Sarsarietellus Campaner, 1984 



8b Antennulary segments XXV and XXVI fused; basal spine of 

 maxilla bare; outermost seta on sixth endopod segment of 

 maxilliped not vestigial; genital double-somite (9) with copula- 

 tory pore located posteroventrally; seminal receptacle not elon- 

 gate, its distal end not bulbous; inner process of leg 5 (9) with 

 0-2 setae ParamisophriaT. Scott, 1897 



Acknowledgements. We express our sincere thanks to Drs K. 

 Hulsemann and A. Fosshagen for critical reading of the manuscript. 

 We are also grateful to Dr. F.D. Ferrari, Dr. J.M. Bradford-Grieve, 

 Mr. P. Anderson, Miss V. Wilhelmsen and Dr. C.E.F. da Rocha for 

 lending us material. Thanks are due to Mr. R. Huys and the staff of 

 the Electron Microscopy Unit of The Natural History Museum, 

 London for their kind assistance, and to the captain and crew of 

 T.R.V. Toyoshio-maru of Hiroshima University for their coopera- 

 tion at sea. The first author (SO) appreciates Prof. T. Onbe for his 

 encouragement during the present study. The present study was 

 supported in part by Narishige Zoological Award (1992) and the 

 Fujiwara Natural History Foundation (1994) awarded to the first 

 author (SO). 



REFERENCES 



Alvarez, M.P.J. 1985. A new arietellid copepod (Crustacea): Pilarella longicor- 



nis, gen. n., sp. n., from the Brazilian continental shelf. Revista Brasiteira de 



Zoologia, 28: 189-195. 

 Andronov, V.N. 1974. Phylogenetic relations of large taxa within the suborder 



Calanoida (Crustacea, Copepoda). Zoologicheskij Zhurnal. 53: 1002-1012. 



(In Russian) 



