JOHNSON: PERCOIDEI 



489 



Table 121. Continued. 



pletion of dorsal fin rays (12-30 mm) occurs in the elongate 

 larvae of Coryphaena. Rachycentron and the Echeneididae. 



The most commonly observed sequence of fin completion 

 (pattern A in Table 1 2 1 ) is that described for Moronehy Fritzsche 

 and Johnson (1980) and for Anisolremus by PotthofTet al. ( 1 984). 

 Soft rays of the dorsal and anal fins begin to form during or just 

 prior to flexion. Fin rays appear first near the future middle of 

 these fins and are added in an anterior and posterior direction. 

 Full complements of dorsal and anal soft rays are usually achieved 

 at about the same time as the full principal caudal fin ray com- 

 plement. The spinous dorsal fin is completed next (usually from 

 posterior lo anterior) followed by the pelvic and pectoral fins. 



Precocious development of the anterior portion of the spinous 

 dorsal and the pelvic fins, pattern B, is usually associated with 

 ornamentation and/or elongation of the spines. It characterizes 

 all larvae of lutjanids and epinepheline serranids, and a few 

 apogonids, chaetodontids and sciaenids. In liopropomine ser- 

 ranids, the anterior portion of the spinous dorsal is precocious, 

 but the pelvic fins develop last. Precocious development of pec- 

 toral and pelvic fins, pattern C, is unique to some members of 

 the Bramidae. Pattern D, precocious pectorals only, is found in 

 scatophagids, some bramids, and interestingly, is also shared 

 by the freshwater Percichthyidae and some Percidae. The pec- 

 toral fin and anterior portion of the spinous dorsal are precocious 

 in the serranid tribe Grammistini. In pattern E, the full anal fin 

 ray complement tends to be complete prior to that of the dorsal, 

 and the spinous dorsal is the last fin to be completed. This 

 pattern is unique to the echeneoid fishes (Coryphaenidae, Ra- 

 chycentridae and Echeneididae). Pattern F, in which only the 

 pelvics are precocious, is found in Hapalogenys. Monodactyl- 

 idae and Pempherididae. 



Scales. — MoiX percoids begin to develop scales well after com- 

 pletion of fins near the end of the larval period, frequently after 

 settling. In several families (e.g., Chaetodontidae, Cheilodac- 

 tylidae, Cirrhitidae, and Scorpididae) unspecialized scales first 

 appear at or slightly before completion of the median fins and 

 are thus present during the late larval stages. Larvae of a few 

 groups are characterized by early development of specialized 



spinous scales that eventually transform into the typical adult 

 ctenoid scale. In the ephippidid Chaetodiplerus. the haemulid 

 Conodon. malacanthids, pomacanthids and scatophagids these 

 consist of small, roughly circular, non-imbricate bony plates 

 from the center of which one to several spines project outward 

 at right angles. Larvae of the Bramidae, Kyphosidae, Pentacer- 

 otidae, Priacanthidae, some anthiin serranids, the sparid Pagrus 

 and the sparoid family Lethrinidae possess spinous scales in 

 which one or more spines project outward at less than right 

 angles from the posterior field or margin of imbricate plates that 

 more closely resemble scales of the adults. Among non-percoid 

 fishes, spinous larval scales occur in trachichthyids, chiasmo- 

 dontids, acanthurids, Xiphias, Anttgoma and some pleuronec- 

 tiforms, telraodontiforms, scorpaeniforms and gasterostei- 

 forms. The function of specialized larval scales is unknown, but 

 it seems likely that they provide some defense against small 

 biting predators, parasites and/or nematocysts. 



Head spination.— The simple to elaborate spinous ornamenta- 

 tion of various bones of the head in larvae of many percoid 

 fishes is an area ripe for future detailed investigations. Nowhere 

 is the potential utility of larval morphology in phylogenetic 

 studies more evident, for it is in this feature that larval percoids 

 frequently exhibit far more complexity and diversity than adults. 

 Although more work is needed to determine if patterns of head 

 spination will prove useful in studies of interfamilial relation- 

 ships, there can be no doubt that the diversity of these patterns 

 within some well-defined families or subfamilies (e.g., anthiin 

 serranids, chaetodontids, priacanthids, malacanthids, poma- 

 canthids. haemulids. etc.) offer critical information for intra- 

 familial phylogenetic analyses. 



Extensive head spination appears to have arisen indepen- 

 dently numerous times within the Percoidei. Nevertheless, an 

 ordered progression of increasing complexity is evident in the 

 sequence in which ornamentation is added to various bones. 

 Most families are characterized by a single level of complexity, 

 but some are more diverse. In the larvae of several unrelated 

 families (e.g., Cheilodactylidae, Echeneididae, Menidae, Mul- 

 lidae, Percichthyidae) head spines are completely lacking. A 



