equatorial in distribution and the larvae of £. imus were 

 taken on a few EASTROPAC stations. 



It is the purpose of this paper to present information 

 and illustrations (including keys) for the identification of 

 the larvae of eastern Pacific scorpaenids to genus and, for 

 each genus, to describe and illustrate the larval stages of 

 the species for which larvae are known. 



Sebastes is the most extensively treated. In addition to 

 summaries of the earlier descriptions of S. paucispinis 

 and S. macdonaldi, we include new descriptions of larvae 

 of S. jordani, S. levis, S. cortezi, and S. sp. (Gulf of 

 California Type A). Also, we describe larval series of 

 three North Atlantic species — S. marinus, S. uiviparus, 

 and S. fasciatus. Our purpose in doing this is to sup- 

 plement the already substantial literature on larvae of 

 these species with heretofore unreported characters and 

 to provide a basis for comparison of larvae of Atlantic 

 and Pacific Sebastes. Larval series of a Sebastes from off 

 Chile and eight species from Japan are described and il- 

 lustrated to allow comparison of northeastern Pacific lar- 

 vae with those from the Southern Hemisphere and 

 western Pacific. Essentially we are treating Sebastes on a 

 worldwide basis. 



Since larvae of the eastern Pacific representative of 

 Helicolenus, H. lengerichi, were not available, we in- 

 clude a description of the Atlantic species, H. dactylop- 

 terus, so that larvae of Helicolenus may be compared 

 with those of other eastern Pacific genera. Many of the 

 characters presented in this description have not been 

 previously reported. 



Larvae and juveniles of Sebastolobus have been 

 thoroughly described (Moser 1974) and are briefly sum- 

 marized here. The larvae of Trachyscorpia are unknown 

 but if their relationships are with Sebastolobus as Esch- 

 meyer (1969) suggests, then they probably will resemble 

 the larvae of Sebastolobus but with lower counts of most 

 meristics. 



Life history stages of Scorpaenodes have not been de- 

 scribed and we give a detailed account of larvae and early 

 juveniles of the single eastern Pacific species, S. xyris. 

 The literature contains life history accounts of three 

 Mediterranean and North Atlantic species of Scorpaena 

 and descriptions of the eggs and newly hatched larvae of 

 a single eastern Pacific species, S. guttata (see literature 

 review for the genus). We include descriptions of a com- 

 plete larval series of S. guttata and of another Scorpaena 

 not identifiable to species. Larvae of Pontinus have not 

 been previously described and we describe larvae of two 

 forms of this genus. Two larval specimens of Ec- 

 treposebastes imus have been briefly described (Esch- 

 meyer and Collette 1966) and we describe a complete 

 developmental series of this species for the first time. 



Seven of the eight genera of scorpaenids that occur in 

 the eastern Pacific also occur in the Atlantic. According 

 to Eschmeyer (1969, 1971) who reviewed the scorpion- 

 fishes of the Atlantic Ocean, 55 of the 60 species (i.e., 

 92't) of Atlantic scorpaenid fishes belong to these seven 

 genera. Since there is a strong similarity between the 

 scorpaenid fauna of the two oceans at the generic level, 

 the guide provides a starting point for identification of 



scorpaenid larvae in the tropical and subtropical Atlan- 

 tic. 



In addition to the genera treated in this guide, the 

 literature contains relatively few other life history de- 

 scriptions of scorpaenid fishes. We are aware of pub- 

 lications on only three other genera: Pterois (P. lunulata. 

 Mito and Uchida 1958; Mito 1963), Inimicus {I. 

 japonicus, Fujita and Nakahara 1955), and Sebastiscus 

 {S. marmoratus, Tsukahara 1962). We are hopeful that 

 our guide will stimulate further investigations on the 

 developmental stages of this large and diverse family. 



Relationships among the eastern Pacific genera can be 

 shown by their groupings into subfamilies. We are follow- 

 ing the classification presented by Matsubara (1943) and 

 amended for the subfamily Setarchinae by Eschmeyer 

 and Collette (1966) and Sebastolobinae by Eschmeyer 

 (1969). The eight genera of eastern Pacific scorpaenids 

 belong to four subfamilies, as follows: 



Subfamily Sebastinae 



Sebastes Cuvier 



Helicolenus Goode and Bean 

 Subfamily Sebastolobinae 



Sebastolobus Gill 



Trachyscorpia Ginsburg 

 Subfamily Scorpaeninae 



Scorpaenodes Bleeker 



Scorpaena Linnaeus 



Pontinus Poey 

 Subfamily Setarchinae 



Ectreposebastes Garman 



Among the primary characters for separation of adult 

 scorpaenid fishes into subfamilies are the shape of the 

 2nd suborbital (3rd infraorbital) bone, whether this bone 

 is fastened to the preopercle or remains free, and the 

 presence or absence of 3rd and 4th suborbital bones. The 

 suborbital sensory canal, which runs backward from the 

 preorbital to the 2nd suborbital in all scorpaenids has a 

 branch extending through the 3rd and 4th suborbital 

 bones to the 5th suborbital bone in some scorpaenids. 

 The latter branch is developed in eastern Pacific scor- 

 paenids that retain the 3rd and 4th suborbital bones. 

 Characters associated with the suborbital bones are sum- 

 marized for the eastern Pacific genera and subfamilies in 

 Table 1 together with meristic characters, type of 

 reproduction, and presence or absence of a gas bladder in 

 juveniles and adults. 



MATERIALS AND METHODS 



Specimens used in this study were obtained from a 

 variety of sources. The CalCOFI plankton collections 

 from the California Current region provided most of the 

 larval specimens of Sebastes and Sebastolobus. CalCOFI 

 collections from the southern end of the station pattern 

 off Baja California and from the Gulf of California 

 provided larvae of Sebastes, Scorpaena, Pontinus, and 

 Scorpaenodes. Larvae of the latter three genera were also 



