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



Table l.-Morphometric comparison of species and populations of Sardini. Means as thousandths of fork length or head length. 



cular system, pharyngeal muscles, urogenital 

 system, and olfactory organ. 



VISCERA 



Emphasis was placed on the appearance of the 

 viscera in ventral view, after removal of an oval 

 segment of the belly wall (Figure 3). Important 

 papers on the viscera of bonitos include 

 Kishinouye (1923 - Sarda and Gymnosarda), God- 

 sil (1954, 1955 - Sarda), Postel (1954 - Orcynopsis), 

 Blanc and Postel (1958 - Gymnosarda), Silas (1963 

 - Gymnosarda), and Nakamura and Mori (1966 - 

 Allothunnus). 



General Description. —The anterior end of the 

 liver abuts against the transverse septum 

 anteriorly in the body cavity. There are usually 

 three lobes to the liver: the middle lobe is con- 

 spicuous in ventral view in all bonitos, whereas one 



or both lateral lobes are visible only in Gymnosar- 

 da and Sarda. No striations are present on the 

 surface of the liver as they are in four species of 

 Thunnus (see Gibbs and Collette 1967). Two 

 efferent (venous) vessels lead directly from the 

 anterior surface of the liver into the sinus venosus 

 in all species. The short esophagus leads into the 

 stomach. The intestine arises from the anterior 

 end of the stomach which extends posteriorly as a 

 blind sac. The caecal mass covers 22-81% of the 

 anterior part of the body cavity and opens into the 

 intestine immediately posterior to the junction of 

 intestine and stomach. The intestine forms a loop 

 anteriorly. The remainder of the digestive tract is 

 straight in Sarda, but two additional loops are 

 present in the mid-intestine of Cybiosarda, Gym- 

 nosarda, and Orcynopsis. 



The spleen is prominent in ventral view in 

 Gymnosarda and Sarda, but is hidden by the liver 

 and caecal mass in Allothunnus, Cybiosarda, and 



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