FISHERY BULLETIN: VOL. 82. NO. 4 



paired basipterygia which make up the pelvic 

 girdle. The bones are united along the midline 

 and are imbedded in the ventral abdominal wall 

 free from contact with any other bones. Each 



r 



a 



FIGURE 45. — Left second postcleithra in lateral view. a. Scom- 

 beromorus queenslandicus. Great Barrier Reef, 641 mm FL, 

 lx. b. Scomberomorus koreanus, Indonesia, 480 mm FL, 

 1.5 x. c. Acanthocybium solandri, Revillagigedos Is., 1,068 

 mm FL, lx . d. Grammatorcynus bilineatus, New Guinea, 382 

 mm FL, 2x . 



basipterygium is composed of three main parts 

 (Fig. 46): a wide anterodorsal plate; a thin, flat 

 anterior process (anterior xiphoid process of 

 de Sylva 1955, anteromesial process of Devaraj 

 1977); and a strong posterior process (posterior 

 xiphoid process of de Sylva 1955). There are three 

 wings to the anterodorsal plate (Kishinouye 

 1923): lateral (external), mesial (internal), and 

 ventral (vertical). Anteriorly, the lateral wing 

 turns into the same vertical plane and merges 

 into the ventral wing. The mesial wing and the 

 lateral wing meet in one plane posteriorly along 

 a ridge. 



To compare the pelvic girdles, the lengths of all 

 three parts were measured from their bases to 

 their tips. The anterior process comprised 15-52% 

 of the length of the anterodorsal plate. The long- 

 est anterior processes were in Grammatorcynus 

 (46-51%, Fig. 46d), Acanthocybium (35-47%, Fig. 

 46c), and seven species of Scomberomorus: sierra 

 (38-52%), concolor (36-44%), regalis (31-44%, 

 Fig. 46a), semifasciatus (35-36%), sinensis (35%), 

 tritor (32-36%), and maculatus (28-36%). The 

 shortest anterior processes were in three species 

 of Scomberomorus: koreanus (15-30%), multi- 

 radiatus (21-26%), and lineolatus (23-33%, Fig. 

 46b), but there is a large range of variation 

 within species. The posterior process comprised 

 20-85% of the length of the anterodorsal plate. 

 The longest posterior processes were in four 

 American species of Scomberomorus: regalis (78- 

 90%), brasiliensis (81%), sierra (62-85%), and 

 concolor (67-68%). The other two species that 

 belong to this group have shorter posterior pro- 

 cesses: maculatus (38-48%) and tritor (36-50%). 

 The shortest posterior processes were in five 



FIGURE 46. — Right basipterygia of the pelvic girdle in mesial view. a. Scomberomorus regalis, Miami, Fla., 469 mm FL, 1.5 x . b. 

 Scomberomorus lineolatus, Palk Strait, India, 428 mm FL, 2 x . c. Acanthocybium solandri, Miami, Fla., 1,403 mm FL, lx . d. Gram- 

 matorcynus bilineatus, Queensland, 521 mm FL, 1.5 x . 



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