A Key to Genera of the Penaeid Larvae and Early 

 Postlarvae of the Indo-west Pacific Region, with 



Descriptions of the Larval Development of 



Atypopenaeus formosus Dall and Metapenaeopsis 



palmensis Haswell (Decapoda: Penaeoidea: Penaeidae) 



Reared in the Laboratory 



Christopher J. Jackson, Peter C. Rothlisberg, Robert C. Pendrey, and Mair T. Beamish 



ABSTRACT: The penaeid prawns Atypopenaeus 

 formosus Dall and Metapenaeopsis palmensis Has- 

 well were induced to spawn and their larvae and 

 postlarvae were cultured in the laboratory. Three 

 protozoea, three mysis, and early postlarval sub- 

 stages are described for each species. A key to gen- 

 era of the penaeid larvae and early postlarvae of the 

 Indo-west Pacific region was constructed from this 

 information, from other unpublished data from our 

 own larval reference collection, and from previ- 

 ously published larval descriptions. The key, based 

 entirely on laboratory-reared larvae, identifies the 

 genera Atypopenaeus, Macropetasma, Metape- 

 naeopsis, Metapenaeus, Parapenaeopsis, Parape- 

 naeus, Penaeus, and Trachypenaeus. A sternal 

 spine formula, a previously undescribed taxonomic 

 character, is used for identifying postlarvae. 



Twelve genera of penaeid prawns are found in 

 the Indo-west Pacific: Atypopenaeus, Fun- 

 chalia, Heteropenaeus, Macropetasma, Meta- 

 penaeopsis, Metapenaeus, Parapenaeopsis, 

 Parapenaeus, Penaeopsis, Penaeus, Trachy- 

 penaeopsis, and Trachypenaeus. Most of these 

 genera are widespread and common; the excep- 

 tions are the monospecific genus Macropetasma, 

 which occurs only near the southern coast of 

 South Africa, and Heteropenaeus and Trachy- 

 penaeopsis, which are widespread but rare (Dall 

 el al. in press). 



In spite of the worldwide distribution, abun- 

 dance, and commercial importance of penaeids, 

 ecological studies of their larvae have been ham- 

 pered by taxonomic problems (Rothhsberg et al. 

 1983a). Several keys to larval penaeid genera 



Christopher J. Jackson, Peter C. Rothlisberg, and Robert 

 C. Pendrey: Division of Fisheries, CSIRO Marine Labora- 

 tories, P.O. Box 120, Cleveland, QLD 4163, Australia. 

 Mair T. Beamish, 51 Salerno St., Isle of Capri, QLD 4217, 

 Australia. 



Manuscript Accepted May 1989. 

 Fisheries Bulletin, U.S. 87: 703-733. 



have been pubhshed; however, none of these are 

 suitable for use in the Indo-west Pacific region. 

 Cook's (1966a) key to the Gulf of Me.xico penaeid 

 genera was a milestone, and remains the most 

 useful reference. However, many Indo-west 

 Pacific genera do not occur in both regions (e.g., 

 Atypopenaeus and Metapenaeus) and therefore 

 could not be included. Xiphopenaeus is included 

 but does not occur in the Indo-west Pacific. 

 Sicyonia and Solenocera, which Cook included, 

 are now regarded as separate families in the 

 superfamily Penaeoidea (Bowman and Abele 

 1982). 



The keys of Hassan (1974), Haq and Hassan 

 (1975), and Muthu et al. (1978) dealt with three 

 genera in the Indo-west Pacific — Penaeus, 

 Metapenaeus, and Parapenaeopsis — while 

 Paulinose (1982) covered all genera except Het- 

 eropenaeus and Macropetasma. He also included 

 the nonpenaeids Sicyonia, Aristaeomorpha, and 

 Solenocera. However, many of the identifica- 

 tions in Paulinose's work are based on doubtful 

 reconstructions from the plankton and the key 

 has several practical shortcomings (see Discus- 

 sion). 



Penaeus and Metapenaeus have worldwide 

 commercial importance in fisheries and aquacul- 

 ture, and the larvae of many species have been 

 reared in the laboratory and described (for 

 review see Dall et al. in press). There have been 

 very few laboratory studies that describe the 

 larval morphology of the remaining penaeid gen- 

 era in the Indo-west Pacific region. Parapenae- 

 opsis stylifera larvae were reared and described 

 by Rao (1973) and Hassan (1984). Thomas et al. 

 (1975) also reared the larvae in the laboratory 

 but provided no figures or detailed descriptions. 

 Macropetasma africanum was reared and 

 described by Cockcroft (1985). Heldt (1938) 

 described Parapenaeus longirostris, but all 



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