353 



Abstract.— Five rockfish juveniles 

 ( 15.0-30.4 mm SLi collected in midwa- 

 ter trawls from offshore banks off the 

 coast of California were identified by 

 using a combination of morphological 

 and molecular characters. All had pig- 

 ment patterns consistent with members 

 of the subgenus Sebastomus. but each 

 required the use of molecular markers 

 for species identification. Using DNA 

 sequence data from the mitochondria! 

 cytochrome b. we identified the juve- 

 niles as a transforming larva ofSehastes 

 constellatus and a transforming larva 

 and three pelagic juveniles of S. ensi- 

 fer. We provide detailed descriptions 

 of the specimens and compare our 

 results with the developmental stages 

 of other species of Sehastes of the sub- 

 genus Sebastomus. We found some dif- 

 ferences in structure and pigmentation 

 that might allow identification of these 

 young stages by traditional means, but 

 more descriptive work is necessary. 

 The use of molecular tools can thus be 

 successfully used to complement tra- 

 ditional identification efforts to solve 

 problems unassailable by morphologi- 

 cal and pigment characters alone. 



Molecular identification and description of 



pelagic young of the rockfishes 



Sebastes constellatus and Sebastes ensifer 



AxayacatI Rocha-Olivares 



Scnpps Institution of Oceanography 



University of California San Diego 



9500 Gilman Dr, La lolla, California 92093 0208 



Present address, Louisiana State LIniversity 



Department of Biological Sciences 



508 Life Sciences Building 



Baton Rouge, Louisiana 70809- 17'5 



E-mail address arocha^alsu edu 



H. Geoffrey Moser 



Jason Stannard 



La Jolla Laboratory 

 Southwest Fishenes Science Center 

 National Marine Fishenes Service, NOAA 

 PO, Box 271, La Jolla California 92038 



Manuscript accepted 28 September 1999. 

 Fish. Bull. 98:353-363 (2000). 



Live-bearing rockfishes of the genus 

 Sebastes constitute the largest genus 

 of scorpaeniform fishes with about 

 110 species woridwide, 72 of which 

 reside in the Northeast Pacific ( Esch- 

 meyer and Herald, 1983; Kendall, 

 1991; Nelson, 1994). In this geo- 

 graphic region, rockfishes are very 

 important in the bottom trawl fish- 

 ery as well as in recreational fisher- 

 ies (Lenarz, 1986; Leet et al., 1992; 

 Low, 1993 ). Newborn rockfishes are 

 extruded as first-feeding larvae 

 from viviparous females (Yoklavich 

 and Boehlert, 1991), and they rank 

 among the most frequent and abun- 

 dant of all fish larvae in plankton 

 collections off the coasts of Califor- 

 nia and Oregon (Moser et al., 1993; 

 Moser, 1996; Doylei). The juvenile 

 stages of Sebastes are also impor- 

 tant ecologically as prey of larger 

 fishes and birds (Love et al., 1991; 

 Moser and Boehlert, 1991;Ainley et 

 al., 1993). In addition to their bio- 

 logical significance, rockfish larvae 

 and early juveniles have received 

 much attention for. their potential 

 use in estimating spawning bio- 

 mass and recruitment (Moser and 



Butler, 1987; Hunter and Lo, 1993; 

 Ralston and Howard, 1995). 



Species identification has been 

 the most challenging aspect in the 

 study of the early life history stages 

 of Sebastes. For instance, of the 

 59 species distributed in the Cali- 

 fornia Cooperative Oceanic Fisher- 

 ies Investigations ( CalCOFI ) region, 

 complete developmental series are 

 available for only thirteen and par- 

 tial series are available for an addi- 

 tional eight (Moser, 1996). Several 

 factors have influenced this lack of 

 a complete developmental series, 

 including a very large number of 

 sympatric species, the preponder- 

 ance of small larvae, and the limited 

 number of taxonomic characters 

 identifiable in the early stages 

 (Sakuma and Laidig, 1995; Moser, 

 1996; Moser et al., 1977). Alterna- 

 tive methods involving the analysis 

 of electrophoretic patterns or DNA 



' Doyle, M. 1992. Patterns in distribu- 

 tion and abundance of ichthyoplankton off 

 Washington, Oregon, and northern Cali- 

 fornia 11980-19871. U.S. Dep. Commer. 

 NOAANMFSAlaskaFish.Sci. Center Pro- 

 cess Report 92-14, 344 p. 



