PEREZ FARFANTE: REVISION OF GENUS PSEUDARISTEUS 



-A-C 

 D 



E 



-f 



i ' 



Figure \.—Pseudaristeus kathleenae n. sp., 9 35 mm CL, Lagonoy Gulf, east of southern Luzon, Philippines. A. Mandible. B, First 

 maxilla. C, Second maxilla. D, First maxilliped. E, Second maxilliped. /, Rudimentary arthrobranchia. /', Enlargement of/. 

 (All from left side). Scales: A-E = 3 mm;/' = 1 mm. 



at which the specimens were obtained, but because 

 open nets were used in collecting, it is not possible 

 to ascertain the actual level at which the shrimp 

 entered the net. 



Pseudaristeus is quite close to Aristeus, having 

 the same branchial formula, but differing from it in 

 exhibiting a well-marked cervical sulcus which 

 reaches the dorsomedian carina of the carapace and 

 in possessing a postcervical sulcus. Among the mem- 

 bers of Pseudaristeus only males of P. gracilis ex- 

 hibit a sinuous ventral antennular flagellum, a 

 feature characteristic of the males of all species of 

 the genus Aristeus. This similarity, together with 

 a branchial formula common to the two genera, in- 

 dicates a close affinity between members of the 

 genera Pseudaristeus and Aristeus and is a con- 

 vincing basis for the postulate that they have had 



a more recent common ancestor than either share 

 with Hemipenaeus. The species now assigned to 

 Pseudaristeus were placed in the genus Hemipen- 

 aeus by almost all authors in this century until 

 Crosnier (1978) proposed that they be removed to 

 his new genus. 



Key to species of Pseudaristeus 



1. Ventral extremity of cervical carina blunt, 

 not forming sharp-edged arc. Anterolateral 

 carina present. Posterior part of hepatic 

 sulcus not fusing with branchiocardiac sulcus 

 but extending longitudinally subparallel to 

 latter P. speciosus 



Ventral extremity of cervical carina forming 



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