546 



ONTOGENY AND SYSTEM ATICS OF FISHES -AHLSTROM SYMPOSIUM 



Fig. 295. Larva (upper) of an unidentified scarid, 9.3 mm SL, collected on RA' OREGON II cruise 7239, station 54, 18°58'N latitude, 080°09'W 

 longitude, July 30, 1972; [meristic characters for Atlantic scarids and the labrid Doralonotus megalepis are identical] (drawn by B. Washington): 

 and larva (lower) of Oda.x pul/us, 12.2 mm SL, from New Zealand (drawn by J. C. Javech). 



labrid lai^ae settle out at less than 1 5 mm, but some may remain 

 pelagic until 25 mm. 



Scarids spawn pelagic eggs: the subfamily Scarinae appears 

 to spawn spindle-shaped eggs, and the subfamily Sparisomatin- 

 ae to spawn spherical eggs (Table 131). Morphologically, scarid 

 larvae are similar to many labrids: they are elongate and com- 

 pressed; have an initially straight, rugose gut that later coils; 

 lack head spines; have squarish to narrow eyes; and usually 

 develop choroid tissue (Fig. 295). Scarid larvae differ most strik- 

 ingly from labrid larvae in melanistic pigment. Scarid larvae 

 consistently have melanophores over the posterior gut and have 

 a ventral series of melanophores on the tail. Melanophores in 

 the cardiac region and dorsally on the caudal peduncle are com- 

 monly found in scarids. Melanophores in these regions are either 

 absent or limited to one or two melanophores in tropical labrids. 

 The ventral series of melanophores on the tail of some scarid 

 larvae resembles a set of developing photophores (a histological 

 study is warranted). This ventral pigment plus the narrow eyes 

 and choroid tissue (particularly of sparisomatines) give some 

 scarid larvae a gonostomatid or myctophid appearance, result- 

 ing in some identification problems. Scarines seem to settle out 

 at 10 mm or less, while Calatomus (a sparisomatine) may re- 

 main pelagic until 15 mm. 



Little is known of the early life history of odacids, but they 

 spawn pelagic eggs (Table 131), and their larvae are generally 

 similar to elongate labrids with high numbers of myomeres 

 (Table 131). Only three larvae of two species have been de- 

 scribed, so it is difficult to generalize, but these are elongate. 



compressed, have unlooped guts, no head spines, and round 

 eyes. One species has very elongate, early-forming, anterior spines 

 in the dorsal fin, and a pigment pattern of blotches along the 

 body margins (Fig. 295). The other species is unpigmented and 

 lacks elongate fin elements. 



Relationships 



Kaufman and Liem (1982) include in the Labroidei the Po- 

 macentridae, Cichlidae, Embiotocidae, Labridae, Odacidae, and 

 Scaridae and further include the Odacidae and Scaridae in the 

 Labridae. They consider the Pomacentridae to be the primitive 

 sister group of all the other labroids, the cichlids the primitive 

 sister group of embiotocids and labrids, and embiotocids the 

 primitive sister group of the labrids. 



Labroids are characterized by (1) united or fused fifth cera- 

 tobranchials resulting in the formation of one functional unit, 

 (2) a true diarthrosis between upper pharyngeal jaws and the 

 basicranium without an intervening part of the transversus dor- 

 salis anterior muscle, and (3) the presence of an undivided 

 sphincter oesophagi muscle forming a continuous sheet (Kauf- 

 man and Liem, 1982). 



Kaufman and Liem's (1982) arrangement and composition 

 of the Labroidei receives only limited support from ELH char- 

 acters. The monophyly of the Labroidei cannot be established 

 from early life history characters. Pomacentrid and cichlid lar- 

 vae are morphologically and developmentally nearly indistin- 

 guishable from many percoid larvae (e.g., mullids, gerreids, 

 sparids), while the labrids, scarids, and odacids are quite dif- 



