FISHERY BULLETIN: VOL. 75, NO. 2 



CHARACTERISTICS INVOLVED IN THE EVOLUTION OF SOLENOCERIDAE 

 (See text for explanation) 



Hadropenaeus 



Antennular flagella usually sub- 

 cylindrical, occasionally ven- 

 tral one depressed 



Fifth pereopod flagelliform and 

 considerably longer than fourth 



Petasma with ventral costa free 

 from heavily sclerotized termi- 

 nal part of ventrolateral lobule 



Haliportndes 



Integument firm 



Epigastric tooth separated from rostral 



teeth 

 Posthepatic carina absent 

 Fourth and fifth pereopods relatively 



stout proximally, moderately long 



Mesopen aeus 



Antennular flagella dissimilar, 



dorsal subcylindrical , ventral 



depressed 

 Fourth and fifth pereopods stout 



proximally, fifth moderately 



longer than fourth 

 Petasma with ventral costa fused 



to flexible terminal part of 



ventrolateral lobule 



Carapace proportionately short 

 Rostrum deep, with ventral margin 



convex 

 Submarginal carina absent 



Hymenopenaeus 



Integument thin, flexible 



Epigastric and first rostral teeth widely 



separated from remaining rostral teeth 

 Posthepatic carina present 

 Fourth and fifth pereopods flagelliform, 



very long 



Solenocera 



Antennular flagella strongly flattened, 

 ventral pair forming trough, four 

 together constituting respiratory 

 siphon 



Petasma with dorsolateral lobule 

 bearing terminal process 



Lateral ramus of uropod lacking 

 distolateral spine 



Pleoticus 



Submarginal carina sharp 



Petasma with ventral costa free from 

 flexible terminal part of ventro- 

 lateral lobule 



Petasma with distal part of ventral costa 

 fused to adjacent flexible portion of 

 ventrolateral lobule 



Branchiocardiac carina lacking 



Fourth and fifth pereopods rather stout 



proximally, fifth moderately longer 



than fourth 



Telson with single pair of fixed 



lateral spines only 

 Podobranchia on second maxilliped only 



Solenoceroid ancestor- 



Haliporus 



Telson with pairs of movable spines 



anterior to fixed pair 

 Podobranchia on at least second and 



third maxillipeds 



Carapace elongate 



Rostrum low 



Epigastric and rostral teeth separated by 



intervals regularly decreasing anteriorly 

 Postorbital spine present 



Branchiocardiac and submarginal carinae present 

 Lateral ramus of uropod bearing distolateral 



spine 

 Antennular flagella similar, subcylindrical 

 Podobranchiae on appendages posterior to 



second maxilliped 

 Petasma lacking terminal process 



according to Burkenroad (1963b) "the Recent 

 Peneid which seems in several respects the near- 

 est of these to the stem-form of the relatively 

 primitive suborder Dendrobranchiata." A second 

 line gave rise to Hymenopenaeus and Haliporoi- 

 des, and a third lineage is believed to have been 

 ancestral to two stocks, one of which terminated 

 in Pleoticus and from the other evolved Hadro- 



penaeus, Mesopenaeus, and Solenocera; the latter 

 appears to be the most specialized of all seven 

 genera. 



The members of Solenoceridae, in general, oc- 

 cupy deep water beyond the continental and in- 

 sular shelves; however, most of the species of 

 Solenocera as well as Pleoticus muelleri are re- 

 stricted to shallow water. Mesopenaeus tropicalis 



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