MILLER and SUMIDA: DEVELOPMENT OF CARANX MATE 



separately in the fin complement, although some 

 investigators have apparently done so in pre- 

 senting spiny dorsal meristics for C. mate as 

 I+Vm+I (e.g., Smith, 1965; Munro, 1967). The 

 spine is apparent only upon dissection of juveniles 

 and adults of the omaka. 



A narrow flap of tissue had begun to form over 

 the basal edge margin of the anterior three to 

 four dorsal spines in larvae of 10 mm. It 

 appeared slightly earlier than that for the anal 

 fin. Like the flap over the anal fin base, the dorsal 

 flap had only developed along three-fourths of 

 the length of the dorsal fin base in our largest 

 reared larva (18 mm). 



Pelvic (Ventral) 



The inconspicuous pelvic fin bud appeared in 

 larvae of 4.4 to 5.7 mm, except for two specimens 

 of 3.64 and 3.96 mm which had already formed 

 the fin buds. These appeared as small pro- 

 tuberances just ventral to the liver and gradually 

 differentiated into a larval fin in 6.0 mm larvae. 

 Two or three rays had formed in larvae by 6.2 

 mm, and the adult complement of I, 5 was com- 

 pleted in larvae of 7.7 mm. 



OSSIFICATION 



Eighteen larvae, one of each age group sampled 

 and representative of the size range in the sample, 

 were cleared and stained with alizarin following 

 the technique described by Hollister (1934). 

 (Three 7-day-old larvae were cleared and stained 

 to further define the sequence of tooth formation 

 on the upper jaw. ) The specimens were cleared and 

 stained primarily to confirm the meristics taken 

 and developmental descriptions presented earlier 

 on unstained material. 



In order to determine the limits of precision 

 for our statements derived from these cleared 

 and stained larvae about size of first structural 

 development, length differences among our 

 relatively few specimens were measured. They 

 ranged from 0.1 to 0.2 mm for 2.9-3.5-mm speci- 

 mens, 0.5 mm for specimens 3.5-4.6 mm, and 

 about 1 mm for larger specimens. 



Ahlstrom and Ball (1954) present a thorough 

 discussion of the ossification sequence for the 

 carangid, T. symmetricus (jack mackerel). Our 

 cleared and stained specimens showed exactly the 

 same sequence, but ossification (defined as taking 



up alizarin) of each bone began in smaller omaka 

 larvae than jack mackerel (Ahlstrom and Ball, 

 1954). Likewise, most of these bones had com- 

 pleted ossification at a smaller size in omaka. 



The cleithrum, upper and lower jaw bones, and 

 preopercular spines were already ossified in our 

 2.94 mm larva. Minute teeth (ca. 4 on the upper 

 jaw) had begun staining in the larva of 3.35 mm 

 with numerous small teeth filling in the single 

 row in larger larvae. Teeth on the lower jaw 

 first appeared in the 9.25 mm larve. Five branchi- 

 ostegal rays were stained in the larva of 3.50 mm, 

 with all seven branchiostegal rays on each side 

 of the base of the operculum being stained in the 

 4.58 mm larva. Gill arches were ossified or 

 stained in the 4.09 mm specimen, and gill rakers 

 began staining in the. 5.42 mm larva. Meristics 

 for ossification of fin elements are presented in 

 Table 2. 



All neural and haemal spines and centra of the 

 24 vertebrae (10 abdominal vertebrae, 14 caudal 

 vertebrae) had completed ossification in the 6.25 

 mm larva. The initial vertebral ossification, 

 indicated by the stain in the neural spines of the 

 first few abdominal vertebrae and in the haemal 

 spines of the caudal vertebrae, was present in 

 the 4.09 mm larva. 



Preopercular spines of the omaka larvae were 

 formed along two rows as in the jack mackerel 

 (Ahlstrom and Ball, 1954), viz. the posterior edge 

 of the preoperculum and the "preopercular crest" 

 just anterior to the preopercular edge (as defined 

 by Ahlstrom and Ball, 1954). Those spines 

 situated along the preopercular crest were fewer 

 and smaller than those along the edge of the 

 preoperculum. During the larval development 

 of omaka, the number of spines along the 



Table 2. — Meristics of cleared and stained Caranx mate 

 larvae. Larvae smaller than 4.58 mm are omitted owing to lack 

 of ossification of these fin elements. 



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