EARLY DEVELOPMENT OF SEVEN FLATFISHES OF 

 THE EASTERN NORTH PACIFIC WITH HEAVILY PIGMENTED LARVAE 



(PISCES, PLEURONECTIFORMES) 



B. Y. SuMiDA, E. H. Ahijstrom, and H. G. Moser' 



ABSTRACT 



Eggs and larval series are described for six species of flatfishes occurring off California with heavily 

 pigmented larvae. These are the pleuronectids Pleuronichthys coenosus, P decurrens, P. ntteri, P. 

 verticalis. and Hypsopselta guttulata and the bothid. Hippoglossina stomata. A brief description of 

 postflexion larvae of the Gulf of California species. P ocellatus, is also presented. 



Eggs of Pleuronichthys are unusual among flatfishes in possessing a sculptured chorion composed of 

 a network of polygonal walls, whereas the chonons of Hypsopsetta guttulata and Hippoglossina 

 stomata eggs are smooth and unomamented. Eggs o{ Hypsopsetta guttulata and P. ritteri are unusual 

 among those of pleuronectid flatfishes in possessing an oil globule. 



A combmation of pigmentation, morphology, and meristics can distinguish the seven species of 

 flatfishes with heavily pigmented larvae. Larvae of two species, H guttulata and P. decurrens, have a 

 distinctive pterotic spine on either side of the head. Sizes at hatching, at fin formation, and at 

 transformation are important considerations to distinguish these species. Meristic counts, particularly 

 of precaudal and caudal groups of vertebrae, are important to relate a larval series to itsjuvenile and 

 adult stages and thus substantiate identification of the series. 



This report deals primarily with the eggs, larvae, 

 and early juveniles of flatfishes of the genus 

 Pleuronichthys. Descriptions are included for 

 complete series of larvae of four species, P. decur- 

 rens (curlfin turbot),* P. coenosus (C-0 turbot), P. 

 verticalis (hornyhead turbot), and P. ritteri (spot- 

 ted turbot). A brief account of postflexion larvae of 

 the Gulf of California species, P. ocellatus (Gulf 

 turbot), is also given. Larvae of Pleuronichthys are 

 heavily pigmented, even at hatching, as are those 

 of the pleuronectid, Hypsopsetta guttulata 

 (diamond turbot), and the bothid, Hippoglossina 

 stomata (bigmouth sole). To identify heavily pig- 

 mented flatfish larvae obtained in plankton collec- 

 tions from the eastern North Pacific, it is neces- 

 sary to know the larval developmental, series of all 

 of the above species. These species comprise minor 

 incidental catches within California commercial 

 and sport fisheries and are reported as a general 



'Southwest Fisheries Center La JoUa Laboratory. National 

 Marine Fisheries Service. NOAA. P.O. Box 271. La Jolla. CA 

 92038. 



^The common name turbot is used for all species of 

 Pleuronichthys. a usage consistent with Fitch ( 1963). Miller and 

 Lea (1972). and Gates and Frey (1974:79). The American 

 Fisheries Society's list of common names (Bailey et al. 1970) 

 designates P. coenosus and P decurrens as soles, but we disagree 

 with giving species within a genus different common general 

 names. 



Manuscnpt accepted September 1978. 

 FISHERY BUIXETIN VOL. 77, NO. 1, 1979. 



grouping of "turbots." Species most commonly 

 caught in the fisheries are P. decurrens. P. 

 coenosus, P. verticalis, and Hypsopsetta guttulata 

 (Frey 1971; Bell 1971; Oliphant 1973; Pinkas 

 1974; McAllister 1975). No specific catch data are 

 available for Hippoglossina stomata, but the 

 species is probably caught incidentally and in- 

 cluded in the "miscellaneous sole" category of 

 catch data. 



In a review of the genus Pleuronichthys, Fitch 

 (1963) recognized six species including the five 

 listed above and P. cornutus from off Japan and 

 China. In an earlier review of the genus, Starks 

 and Thompson ( 1910) recognized these six species 

 and P. nephelus Starks and Thompson. Norman 

 (1934) concurred with Starks and Thompson in 

 recognizing seven species. Fitch (1963), however, 

 agreed with Hubbs (1928) in finding no grounds 

 for the separation of P. nephelus from P. coenosus 

 after his examination of the type material of P. 

 nephelus. Fitch's review is thorough; he examined 

 more than 5,700 individuals of the genus. We fol- 

 low his classification. 



The first descriptions of the eggs and early-stage 

 larvae of Pleuronichthys were given by Budd 

 (1940) who dealt with P. coenosus, P. decurrens. 

 and P. verticalis. Orton and Limbaugh (1953) de- 

 scribed the eggs of Hypsopsetta guttulata and P. 



105 



