Bull. nat. Hist. Mus. Lond. (Zool.) 61(2): 91-101 



TH J HAL 



12 DEC 1995 



Preliminary studies on a mandibulohyoid h ucmc0 

 ligament' and other intrabuccal connecti\|f oolqqyubrar\ 

 tissue linkages in cirrhitid, latrid and 

 cheilodactylid fishes (Perciformes : 

 Cirrhitoidei) 



PETER HUMPHRY GREENWOOD* 



Visiting Research Fellow, The Natural History Museum, Cromwell Road, London SW7 5BD and 

 Honorary Research Fellow, J.L.B. Smith Institute of Ichthyology, Private Bag 1015, Grahamstown, 

 6140 South Africa 



CONTENTS 



Introduction 91 



Material and Methods 92 



Ligamentous and other connective tissue linkages between the mandible, the palatoquadrate, the hyoid arch 



and the opercular series in three cirrhitoid families 93 



The family Cirrhitidae 93 



The family Latridae 93 



The family Cheilodactylidae 97 



Discussion and Conclusions 98 



Acknowledgements 100 



References 101 



Synopsis. In certain taxa of at least three groups of percomorph fishes belonging to the cirrhitoid families 

 Cirrhitidae and Latridae, there is a connective tissue linkage between the mandible and the hyoid arch, suggestive of 

 the mandibulohyoid ligament described in certain sub-percomorph groups. This ligament is generally thought to be a 

 feature of lower teleost fishes, although a mandibulohyoid connection has also been identified in a few more derived 

 taxa. The mandibulohyoid connection in the Cirrhitidae examined would appear to originate from the tendinous 

 aponeurosis associated with the Aw division of the adductor mandibulae muscles, but its derivation in the latrid 

 species Acantholatris monodactylus remains undetermined. The Aw aponeurosis in A. monodactylus, as well as in 

 the latrid Mendosoma, and in two genera of Cheilodactylidae (viz. Chirodactylus and Cheilodactylus) ramifies 

 extensively over the paladoquadrate arch and part of the opercular series. This system, together with various 

 intrabuccal ligaments is described from representatives of the three cirrhitoid families studied. 



It is concluded that, contrary to several earlier ideas, a mandibulohyoid linkage is of taxonomically and 

 phylogenetically widespread occurrence in teleosts but that it might be derived from different connective tissue 

 sources. The value of this connective tissue complex in phylogenetic studies has yet to be established, but it appears 

 to be of use in at least establishing intragroup relationships within the Cirrhitoidei. 



INTRODUCTION 



A recent anatomical study of certain cirrhitoid fishes (sensu 

 Greenwood, 1995) has revealed a number of markedly differ- 

 ent ligament and tendon systems which separately or con- 

 jointly link the mandible with the hyoid arch, the 

 palatoquadrate arch and the opercular series. Some of these 

 connections have a degree of complexity not previously 

 recorded among teleost fishes. 

 Of particular functional interest are the two types of direct 



t Dr Greenwood died 3 March 1995. 

 ©The Natural History Museum, 1995 



and ligament-like connections between the ceratohyal and 

 mandible in some cirrhitid species, and a third type found in 

 one of the latrid species examined (family placement after 

 Greenwood, 1995). These linkages invite comparison with 

 the so-called mandibulohyoid ligament generally thought to 

 be commoner in lower teleosts than in perciform taxa, or 

 even restricted to the former groups (see Verraes, 1977; 

 Lauder & Liem, 1980; Lauder, 1982; but see also Osse, 1969, 

 Springer et al, 1977, and Aerts et ai, 1987 for certain 

 perciforms, and Anker, 1974, for gasterosteiforms). A man- 

 dibulohyoid ligament also occurs in the semionotiform lepi- 

 sosteids Lepisosteus and Atractosteus (Wiley, 1976). 



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