TUCKER: LARVAL DEVELOPMENT OF CITHAR1CHTHYS AND ETROPUS 



ined: C. arctifrons, (2) 40, 117 mm SL; C. comu- 

 tus, (1) 51.5 mm SL; C. spilopterus, (2)41.6, -100 

 mm SL; C. macrops, (2) 45.7, ~100 mm SL; E. 

 crossotus, (1) 49.4 mm SL; E. microstomus, (12) 

 ~30-100 mm SL. Radiographs of juveniles and 

 adults also were studied: C. arctifrons, (1) 100 

 mm SL; C. comutus, (16) 30-67 mm SL; C. gym- 

 norhinus, (3) 23-37 mm SL; C. macrops, (75) 47- 

 113 mm SL; C. spilopterus, (65) 23-109 mm SL; 

 E. crossotus, (62) 29-92 mm SL; E. intermedius 

 (cf. E. crossotus), (2) 80, 92 mm SL; E. micro- 

 stomus, (1)66 mm Sh;E. rimosus, (1)104 mmSL. 



Counts 



All larvae were lightly stained with Alizarin 

 Red S in 1% aqueous potassium hydroxide solu- 

 tion for making counts and observing the 

 sequence of ossification. Most specimens were 

 fairly transparent and internal structures were 

 visible without clearing. The following counts 

 were taken from larvae and juveniles with a 

 stereomicroscope: precaudal neural spines, 

 caudal neural spines, hemal spines, precaudal 

 centra, caudal centra (including urostyle), 

 caudal fin rays supported by each hypural ele- 

 ment, dorsal fin rays, anal fin rays, left and right 

 pelvic fin rays, left and right preopercular 

 spines, left and right frontal-sphenotic spines, 

 and left and right upper (premaxillary) and 

 lower (dentary) larval teeth. 



Morphometries 



Measurements of various body parts of repre- 

 sentative specimens were made on the left side 

 with an ocular micrometer in a stereomicro- 

 scope. The only exceptions were standard and 

 total lengths of the six longest C. spilopterus 

 (19.4-25.4 mm SL), which were made with di- 

 viders and a millimeter scale. Measurements are 

 defined as follows: 



Body length (BL) = snout tip to notochord tip for 

 preflexion and flexion larvae (notochord 

 length, NL); snout tip to posterior margin of 

 hypurals for postflexion larvae and juveniles 

 (SL). 



Upper jaw length = snout tip to posterior mar- 

 gin of maxillary. 



Lower jaw length = anterior tip of dentary to 

 posterior margin of articular just above the 

 angular. 



Snout length = horizontal distance from snout 

 tip to anterior margin of left pigmented 

 eye. 



Eye diameter = horizontal diameter of left pig- 

 mented eye. 



Head length (HL) = horizontal distance from 

 snout tip to anterior margin of cleithrum at the 

 body midline. 



Snout to anus length = horizontal distance from 

 snout tip through midline of body to vertical 

 line through anus. 



Total length = snout tip to posterior margin of 

 finfold prior to caudal fin ray development, 

 then to posterior tip of longest caudal ray. 



Head depth = greatest vertical depth of head; in 

 preflexion larvae, this is near or just behind 

 the posterior half of the eye, but with develop- 

 ment the greatest depth is progressively more 

 posterior. 



Body depth at pelvic fin = vertical distance from 

 dorsal to ventral body margin at base of second 

 pelvic ray. 



Body depth at loop of gut = vertical distance 

 from dorsal to ventral body margin at the 

 deepest par t of the gut ( C. comutus and C. gym- 

 norhinus only). 



Body depth at anus = vertical distance from dor- 

 sal to ventral body margin at anus. 



Body depth at third hemal spine = vertical dis- 

 tance from dorsal to ventral body margin at 

 third hemal spine. 



Caudal peduncle depth = prior to dorsal and 

 anal fin formation, the vertical distance from 

 dorsal to ventral body margin at the shallowest 

 part of the caudal peduncle; after dorsal and 

 anal fin formation, at the posterior edge of dor- 

 sal and anal fins. 



Developmental Terminology 



Body length is a useful basis for linking char- 

 acters of unidentified specimens with those in 

 larval descriptions. However, body length may 

 not be the most appropriate basis for comparing 

 larvae of different species, especially bothids, 

 which undergo notochord flexion and transfor- 

 mation at different sizes, usually within a nar- 

 row range for a single species but over a wide 

 range for the family or even within a genus (e.g., 

 Citharichthys). In this paper, both body length 

 and stage of development are indicated for devel- 

 opmental events. Stage of development is de- 

 fined by degree of notochord flexion or degree of 

 transformation. Terminology is similar to that of 



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