376 



Abstract — Rockfish (Sebastes spp.) 

 juveniles are often difficult to identify 

 by using morphological characters. 

 This study independently applies 

 morphological characters and a key 

 based on mitochondrial restriction 

 site variation to identify juvenile 

 rockfishes collected in southern 

 California during juvenile rockfish 

 surveys. Twenty-four specimens of 

 Sebastes were examined genetically 

 without knowledge of the morphologi- 

 cal assignment. Seventeen fish were 

 identified genetically as S. semicinc- 

 tus, S. goodei, S. auriculatus, S.jor- 

 dani, S. levis, S. rastrelliger, and S. 

 saxicola. Identities for the remaining 

 fish were narrowed to two or three 

 species: 1) three fish were either S. 

 carnatus or S. chrysomelas; 2) one 

 fish was either S. chlorosticus, S. eos, 

 or S. rosenblatti; and 3) three fish 

 could have been either S. hopkinsi 

 or S. ovalis, the latter for which we 

 now have distinguishing mitochon- 

 drial markers. The genetic and mor- 

 phological assignments concurred 

 except for the identity of one fish that 

 could only be narrowed down to S. 

 hopkinsi or S. semicinctus by using 

 morphological characters. Genetics 

 excluded more species from multispe- 

 cies groupings than did the morpho- 

 logical approach, especially species 

 within the subgenus Sebastomus. 

 Species in the genetically unresolv- 

 able groups may be similar because of 

 recent divergence or because of inter- 

 species introgression. 



Comparing the identification of southern California 

 juvenile rockfishes (genus Sebastes spp.) 

 by restriction site analysis of the 

 mitochondrial ND3/ND4 region and 

 by morphological characteristics 



Zhuozhuo Li^ 



Mary M. Nishimoto^ 



Milton S. Love^ 



Anthony J. Gharrett' 



' Fisheries Division, School of Fisheries and Ocean Sciences 

 University of Alaska Fairbanks 

 11120 Glacier Highway 

 Juneau, Alaska 99801 



^ Marine Science Institute 

 University of California 

 Santa Barbara, California 93106-6150 

 E mail address (for A, J- Gtiarrett, contact author) ffajgcfluatedu 



Manuscript submitted 11 October 2004 

 to the Scientific Editor's Office. 



Manuscript approved for publication 



21 September 200.5 by the Scientific Editor. 



Fish. Bull. 104:376-382 (2006). 



Sixty-five rockfish species (Sebastes 

 spp.) inhabit the waters along the 

 California coast (Moser, 1996). Within 

 the genus, there is a high degree of 

 similarity among many species in 

 morphological characters. These 

 similarities are in part due to recent 

 divergence, but may also have resulted 

 from convergence of congeners occupy- 

 ing similar habitats. Identification of 

 Sebastes (and most species) is usually 

 based on morphology; however, this 

 approach may fail, especially for iden- 

 tifying sympatric species, which can 

 be similar in coloration and overlap 

 in morphological characters. Juvenile 

 rockfishes are morphologically dis- 

 tinct from larvae and adults (Kendall, 

 2000), and juvenile stages of many 

 species, especially the pelagic juvenile 

 stage, have not yet been described; 

 only a few species have complete 

 ontogenetic descriptions (Matarese et 

 al.,1989; Moser. 1996). The species of a 

 few Sebastes larvae can be determined 

 and adults can be misidentified. 



Rockfishes are important ecologi- 

 cally and some species are economi- 

 cally valuable. Sebastes larvae are a 

 large component of ichthyoplankton 

 collections and rank third or fourth 

 in abundance among all fish larvae 



taken during California Cooperative 

 Fisheries Investigations (CalCOFI) 

 surveys, which cover the entire length 

 of the California and Baja Califor- 

 nia coast and now survey southern 

 California. The ability to identify 

 Sebastes accurately and efficiently 

 at all developmental stages will, in 

 turn, greatly increase our knowledge 

 of their life histories, as well as our 

 management and conservation efforts. 

 An increased understanding of life 

 history variation can improve the sys- 

 tematic descriptions of Sebastes spe- 

 cies, which have mostly been based on 

 the morphology of adults. 



The analysis of restriction site 

 variation of polymerase chain re- 

 action (PCR)-amplified mtDNA is 

 an effective and relatively simple 

 method for species identification of 

 adult specimens of fish species. The 

 use of restriction enzymes to cleave 

 the DNA can reveal variation in the 

 mtDNA sequence at specific sites, and 

 individuals or species can often be 

 distinguished by the presence or ab- 

 sence of these sites. This method has 

 advantages over sequencing in that 

 it can be conducted relatively easily 

 and used to survey large stretches of 

 a DNA sequence, whereas sequencing, 



