Abstract. - Three species of 

 basses iif the genus Paralahrax are 

 found in southern California coastal 

 waters. Adults can be identified on 

 the basis of moqjhological characters, 

 but the eggs and early larval stages 

 of the three species are extremely 

 similar in appearance. This paper re- 

 ports an investigation of biochemical 

 genetic characters for specific iden- 

 tification. An electrophoretic analy- 

 sis of 43 presumptive gene loci dem- 

 onstrated several genetic differences 

 between any two of the three spe- 

 cies, but no single locus was able to 

 unambiguously distinguish the three 

 species. In contrast, an analysis of 

 Parnlahrax mitochondrial DNA 

 (mtDNA) demonstrated that 8 of 13 

 informative restriction endonuleases 

 produced species-specific fragment 

 patterns. A technique is described 

 for the relatively rapid enrichment 

 and analysis of mtDNA from both 

 fresh and ethanol-preserved indi- 

 vidual eggs and early larvae which 

 allows specific identification on a 

 cost-effective basis. 



Biochemical Genetics of Southern 

 California Basses of the Genus 

 Paralabrax: Specific Identification 

 of Fresh and Ethanol-preserved 

 Individual Eggs and Early Larvae 



John E. Graves 



Department of Biology, University of San Diego, San Diego, California 921 10 

 Present address: Virginia Institute of Marine Science, College of William and Mary 

 Gloucester Point, Virginia 23062 



Michelle J. Curtis 

 Paul A. Oeth 



Department of Biology, University of San Diego 

 San Diego. California 921 10 



Robin S. Waples 



Department of Biology, University of San Diego, San Diego, California 921 10 

 Present address Nortfiwest Fishieries Center 



National Marine Fisfieries Service, NOAA 



2725 Montlake Blvd. East, Seattle. Washington 981 12 



Manuscript accepted 21 September 1989. 

 Fishery Bulletin, U.S. 88:.59-66. 



Tlie serranid genus Paralabrax is 

 endemic to the eastern Pacific Ocean 

 and comprises seven species. Three 

 species, the kelp bass P. clathratus, 

 barred sand bass P. nebulifer, and 

 spotted sand bass P. maculatofascia- 

 tus, are common in southern Cahfor- 

 nia coastal waters and all are impor- 

 tant components of the California 

 sport fishery (Oliphant 1979). Adults 

 of these three species can be separ- 

 ated on the basis of morphological 

 differences (Miller and Lea 1972); 

 however, it is not possible at this time 

 to determine the specific identity of 

 field-caught Pa /•/a6ra.r eggs, larvae, 

 or early juveniles using morpholo- 

 gical characters (Butler et al. 1982; 

 R. Lavenberg, Los Ang. Cty. Mus. 

 Nat. Hist., Los Angeles, CA 90007, 

 pers. commun., June 1988). Ecolo- 

 gical studies of the early life history 

 of the three species, as well as stock 

 assessment studies based on the 

 early-life-history stages, have been 

 hampered by the inability to specif- 



ically identify Paralabrax eggs and 

 larvae. 



A variety of biochemical characters 

 have been used to identify the eggs 

 and larval forms of closely related 

 fishes in the absence of discrimin- 

 ating morphological characters. Elec- 

 trophoresis of water soluble proteins 

 (allozyme analysis) has been used to 

 differentiate species of marine fishes 

 which have morphologically similar 

 eggs, larvae and early juvenile stages 

 (Morgan 1975, Smith and Crossland 

 1977, Sidell et al. 1978, Smith et al. 

 1980, Mork et al. 1983, Graves et al. 

 1989). However, due to the small 

 sizes of eggs and larvae, and the pos- 

 sibility of low enzyme activity during 

 early-life-history stages, some studies 

 have reported difficulty in resolving 

 the electrophoretic bands of eggs and 

 very small larvae (Smith and Cross- 

 land 1977, Sidell et al. 1978, Smith 

 et al. 1980, Graves et al. 1989). 



Restriction endonuclease analysis 

 of mitochondrial DNA (mtDNA) has 



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