COLLETTE and CHAO: SYSTEMATICS AND MORPHOLOGY OF THE BONITOS (SARDINI) 



2b 



3a, 

 3b, 

 4a 



2a. Five to ten narrow, dark, longitudinal stripes on upper part of body; no teeth on the tongue; 



spleen prominent in posterior third of body cavity in ventral view Sarda 3 



Body either without stripes or with dark spots above the lateral line and longitudinal dark 

 stripes below; two patches of teeth present on tongue; spleen either concealed or located 



in anterior third of body cavity in ventral view 6 



Spines in first dorsal fin 2023; total vertebrae 50-55 S. sarda (Bloch) 



Spines in first dorsal fin 17-19; total vertebrae 43-46 4 



Total gill rakers on first arch 8-13; supramaxilla narrow (see Figure 32e) 



S. orientalis (Temminck and Schlegel) 



4b. Total gill rakers on first arch 19-27; supramaxilla wider (see Figure 32c-d) 5 



5a. Total gill rakers on first arch 19-21; pectoral rays 25-27, modally 26; teeth sometimes present 

 on vomer; length of first dorsal base 315-343 thousandths of fork length; maxilla 503-539 

 thousandths of head length S. australis (Macleay) 



5b. Total gill rakers on first arch 23-27; pectoral rays 22-26, modally 24 or 25; teeth never present 

 on vomer; length of first dorsal base 267-314 thousandths of fork length; maxilla 460-503 

 thousandths of head length S. chiliensis (Cuvier) 



6a. Body with dark spots above lateral line and dark longitudinal stripes below (see Figure la); 



spines in first dorsal fin 16-18 Cybiosarda elegans (Whitley) 



6b. Body without a prominent pattern of stripes or spots (see Figure 2); spines in first dorsal 

 fin 12-15 



7a. Pectoral rays 21-23; small conical teeth in jaws; total gill rakers on first arch usually 14 or 

 more; interpelvic process bifid; spleen not visible in ventral view; laminae in olfactory 



rosette 25-28; interorbital width 239-310 thousandths of head length 



Orcynopsis unicolor (Geoffroy St. Hilaire) 



7b. Pectoral rays 25-28; jaw teeth very large and conspicuous; total gill rakers on first arch 

 usually 13 or fewer; interpelvic process single; spleen visible on right side of body cavity 

 in ventral view; laminae in olfactory rosette 48-56; interorbital width 321-400 

 thousandths of head length Gymnosarda unicolor (Ruppell) 



PART 1. 

 COMPARATIVE MORPHOLOGY 



The morphological characters useful for distin- 

 guishing the species of bonitos and for evaluating 

 their phylogenetic relationships are divided into 

 six categories: color pattern, scales, morphometry, 

 meristics, soft anatomy, and osteology. 



Color Pattern 



The most strikingly colored species of the Sar- 

 dini, and perhaps the entire family Scombridae, is 

 clearly Cybiosarda elegans (Figure la). The light 

 venter has several stripes reminiscent of the skip- 

 jack tuna, Katsuwonus pelamis (Linnaeus). The 

 dorsum is covered with black spots over a deep blue 

 background. The high first dorsal fin is jet black 

 anteriorly and white posteriorly. The anal and 

 second dorsal fins are yellow. Orcynopsis unicolor 

 (Figure lb) has a high black first dorsal fin as in 

 Cybiosarda, but there the similarity ends because 

 adult Orcynopsis have only a faint mottled pattern 



that has been deliberately exaggerated in the 

 figure. All species of Sarda (Figure Ic) have 

 stripes along their backs but the number of stripes 

 and their alignment varies both interspecifically 

 and intraspecifically. Sarda australis has stripes 

 on the venter as well as on the dorsum. Sarda also 

 has a black first dorsal fin but it is lower and longer 

 than in Cybiosarda and Orcynopsis. Gymnosarda 

 unicolor (Figure 2a) is deep blue without any dis- 

 tinct pattern; Allothunnus fallai (Figure 2b) also 

 lacks distinctive markings. 



Color plates have been published of all the 

 species of bonitos eoccept Allothunnus. Paintings 

 of three Australian species by George Coates were 

 published by Marshall (1964, 1966): Cybiosarda 

 elegans (fig. 345), Sarda australis (fig. 348), and 

 Gymnosarda unicolor (fig. 342). Color illustrations 

 of Orcynopsis unicolor were published by Lozano y 

 Rey (1952, pi. 41, fig. 2-800-mm adult and fig. 

 3-150-mm juvenile) and by Bini (1968:39). Sarda 

 sarda was illustrated by La Monte (1945, pi. 8; 

 1952, pi. 17), Lozano y Rey (1952, pi. 39, fig. 4-500- 

 mm adult), and Bini (1968:37). Walford (1937, pi. 



521 



