FISHERY BULLETIN VOL 77. NO. 1 



ritteri. Larvae of P. verticalis were illustrated in 

 Ahlstrom and Moser (1975), and Eldridge (1975) 

 described and illustrated larvae of//, guttulata. 



MATERIALS AND METHODS 



Eggs, larvae, and somejuveniles were primarily 

 obtained from California Cooperative Oceanic 

 Fisheries Investigations (CalCOFI) collections. 

 These samples were preserved in a consistent 

 manner as described in Kramer etal.( 1972). Addi- 

 tional material was obtained from bay, estuarine, 

 and coastal collections of Occidental College; 

 Southwest Fisheries Center Tiburon Laboratory, 

 National Marine Fisheries Service; California 

 State University at Fullerton; Scripps Institution 

 of Oceanography; Oregon State University; and 

 Humboldt State University. Specimens of P. rit- 

 teri, P. verticalis, and H. guttulata reared at the 

 Southwest Fisheries Center La Jolla Laboratory, 

 National Marine Fisheries Service, were also 

 utilized. 



Egg and oil globule diameters were measured 

 using an ocular micrometer in a stereomicroscope. 

 For eggs that were not perfectly round, the 

 greatest diameter was recorded. Scanning elec- 

 tronmicrographs were made for four kinds of 

 Pleuroniehthys eggs and for eggs of Sy nodus 

 lucioceps (Synodontidae). The greatest diameter 

 of 10 randomly selected polygonal facets of the 

 chorion of Pleuronichthys and Synodus eggs were 

 measured using an ocular micrometer in a com- 

 pound microscope. To do this the chorion was cut 

 into pieces that were laid flat on a glass slide with 

 a cover slip over them. 



The number of specimens examined varied by 

 species, depending on their availability and abun- 

 dance, ranging from several hundred larvae of P. 

 verticalis, the most abundant species, to two lar- 

 vae of P. ocel lotus. For most species, the minimum 

 number of specimens studied is indicated in the 

 morphometric tables with usually twice as much 

 material looked at for pigmentation development. 

 A developmental series of larvae through 

 juveniles was assembled for each species. Mea- 

 surements of selected body parts were taken to 

 provide descriptive and comparative morphomet- 

 ric data. Measurements were made on the right 

 side of each pleuronectid specimen, and on the left 

 side of the bothid, Hippoglossina stomata, using 

 an ocular micrometer in a stereomicroscope. Ter- 

 minology used in the morphometric tables is as 

 follows: 



Body length = In preflexion and flexion stages, 

 horizontal distance from tip of snout to tip of 

 notochord, referred to as notochord length 

 (NL); in postflexion stages, from tip of snout 

 to posterior margin of hypural elements, i.e., 

 standard length (SL). 



Snout to anus = Horizontal distance from tip of 

 snout through midline of body to vertical 

 through anus. 



Head length = Horizontal distance from tip of 

 snout through midline of head to margin of 

 cleithrum preceding the pectoral fin base. 



Snout length = Horizontal distance from tip of 

 snout to anterior margin of pigmented re- 

 gion of eye. 



Eye width = Horizontal distance through midline 

 of pigmented eye. 



Eye height = Vertical distance through center of 

 pigmented eye. 



Body depth at pectoral base = Vertical distance 

 across body at pectoral fin base prior to for- 

 mation of dorsal fin pterygiophores. An as- 

 terisk follows this measurement in the mor- 

 phometric tables when it includes the depth 

 of dorsal fin pterygiophores. 



Body depth at anus = Vertical distance across 

 body at anus prior to formation of dorsal fin 

 pterygiophores. An asterisk follows this 

 measurement when it includes the depth of 

 the dorsal fin pterygiophores. 



Caudal peduncle depth = Vertical distance across 

 tail immediately posterior to terminal dor- 

 sal and anal fin rays. 



Caudal peduncle length = Medial horizontal dis- 

 tance from vertical through terminal dorsal 

 and anal fin rays to posterior margin of 

 hypural elements. 



Snout to pelvic fin origin = Horizontal distance 

 from tip of snout to vertical through origin of 

 right pelvic fin (left in H. stomata). 



Larval specimens for each species were not 

 available in sufficient numbers to clear and stain 

 for complete data on meristics and sequence of 

 ossification of bony elements. However, fin ray 

 counts were made and tabulated on unstained 

 specimens. A partial larval series of P. verticalis, 

 our most abundant species, was cleared with KOH 

 and stained with Alizarin Red-S by Hollister's 

 method (1934) to determine the process of axial 

 skeletal development and fin formation. In addi- 

 tion, several larvae of P. coenosus and P. decur- 

 rens were cleared and stained for precaudal and 



106 



