P.H. GREENWOOD 



logical and histochemical study are available. 



Intragroup relationships within the cirrhitoids, 

 and the ranking of the group 



Within the cirrhitoids, the Cirrhitidae should be ranked as the 

 most plesiomorphic taxon, a view seemingly implicit in 

 Regan's (1911) diagram of relationships. My reasons for 

 giving the family this ranking are based on urohyal form, the 

 low vertebral count (26-28) relative to that in other families, 

 the absence of parapophyses on the first three abdominal 

 vertebrae, sessile ribs associated with these vertebrae, the 

 presence of 3 predorsal bones (2 in the other cirrhitoids 

 radiographed or dissected) and the presence of a suborbital 

 shelf (which, however, is also developed in the Cheilodactyl- 

 idae [but see below]). Furthermore, the Cirrhitidae are the 

 only cirrhitoids with a basal percoid type of myotome 

 arrangement in the sternohyoideus muscle, a feature not 

 previously noted. That is, one in which the three pairs of 

 hypaxial myomeres forming the sternohyoideus muscle are all 

 arranged in a vertical series, with the first block covering the 

 anterior part of the urohyal (Fig. 4A). Members of all other 

 cirrhitoid families, in contrast, have the first (i.e. anterior) 

 hypaxial myotome of each side displaced ventrally so that it 

 now lies medially and horizontally (not, as in cirrhitids, 

 laterally and vertically) to form, with its antimere, a ventral 

 muscle, paired in most species but in some with the left and 

 right parts fused over most of their lengths to form a single 

 median muscle (Fig. 4B). Single or paired, this ventro-medial 

 component of the sternohyoid runs from the urohyal tip to 

 the prominent ventral projection at the symphysis of the left 



and right cleithra, its origin thus being immediately before 

 that of the anterior infracarinalis muscle insertion. 



In both the Cirrhitidae and in the other families, the 

 sternohyoideus myotomes, except the horizontal first myo- 

 tome in the latter group, are chevron-shaped with the apex 

 directed anteriorly. However, in the latrids, cheilodactylids, 

 chironemids and aplodactylids, the angle between the upper 

 and lower arms of the chevron is more acute, and the lower 

 arm is relatively longer than in cirrhitids. 



Judging from the rather scant literature on the sternohyoid 

 muscle in teleosts (see Winterbottom, 1974), and from a 

 personal knowledge of the situation in percoids, the condition 

 of the muscle in the Cirrhitidae should be ranked as plesio- 

 morphic, that in the other cirrhitoid families as derived and 

 possibly a unifying synapomorphy for the Aplodactylidae, 

 Chironemidae, Latridae and Cheilodactylidae within the lin- 

 eage. 



In Regan's (1911) figure of cirrhitoid intrarelationships 

 referred to above, the Cirrhitidae occupy a basal (i.e. stem 

 position) and are linked, on the one hand to the Chironemi- 

 dae and Aplodactylidae, and on the other to the Cheilodac- 

 tylidae and Latridae (the generic composition of the families 

 being those given by Regan). No reasons were provided by 

 Regan for these supposed relationships, which presumably 

 were based mainly on superficial characters as well as a few 

 anatomical ones. With the anatomical information now avail- 

 able a different scheme of intragroup relationships at the 

 family level can be proposed (see Fig. 5, and Table 1). 



In this scheme, apomorphic features (see Table 1) are 

 taken to be: (i) The derived form of urohyal, of which there 

 are three distinct types (see p. 3). (ii) The presence of a 



ce 



Fig. 4 A. Cirrhitid type organization of sternohyoid 

 myotomes. Drawn from Paracirrhites forsteri; 

 semi-schematic. In this arrangement, the 

 sternohyoid muscles completely envelop the urohyal 

 bone. B. Basic organization of the sternohyoid 

 myotomes in all other families. Drawn from 

 Nemadactylus monopterus; semi-schematic. In taxa 

 of these families, varying an terior extents of the 

 urohyal are not covered by the sternohyoid muscle. 

 1-4: 1st to fourth myotomes of the sternohyoid 

 muscle; c: cleithrum; ce: cut edges of the sterno- 

 hyoid myotomes; uh: urohyal. Drawn by Anthea 

 Ribbink 



B 



ce 



