532 



ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



Fig. 281. Larvae of silver mullet. Mugil curema. (A) Newly hatched, 1.76 mm; (B) yolk-sac stage, 2.15 mm; (C) yolk-sac stage, 2.47 mm; (D) 

 yolk-sac stage, 2.56 mm; (E) yolk-sac stage, 2.56 mm; {¥) 3.7 mm; (G) 4.0 mm; (H) 4.7 mm; (I) 5.3 mm. From Anderson (1957). 



pigmentation pattern, number of anal elements, longitudinal 

 scales, transverse scales, scale morphology, pyloric caeca, and 

 gill rakers. The general profiles of the head, lips, and the labial 

 and lingual teeth are also very useful characters (Tung, 1973; 

 Wallace and van der Elst, 1973; Thomson, 1975; Lai, 1979; 

 Zisman, 1982). 



Relationships 



In some species such as Mugil cephalus, as presently under- 

 stood, which has a worldwide distribution, there is considerable 

 variability in meristic characters and proportional measure- 

 ments. Additional studies are warranted to determine the real 

 extent of genetic exchange between local subunits (Thomson, 

 1982). 



At the generic and specific levels, mugilid taxonomy has not 

 been resolved. As in the case of Mugil cephalus, those species 

 with extensive ranges may be known under different names in 

 various parts of their range. 



A variety of external morphology features have been used to 

 identify genera and species of the adult stages, ranging from 



dentition (Ebeling, 1957, 1961; Farrugio. 1977) and scales 

 (Thomson, 1982), to eye coloration (Alvarez-Lajonchere, 1975). 

 Internal anatomy is valuable in systematic analysis, including 

 the shape and number of pyloric caeca (Perlmutter et al., 1957; 

 Luther, 1975b), the alimentary tract (Thomson, 1966), intestinal 

 convolution (Hotta, 1955), osteology (Luther, 1975a; Mohsin, 

 1978; Kobelkowsky and Resendez, 1972; Sunny, 1971; Hotta 

 and Tung, 1972), and otoliths (Morovic, 1953). 



Phyletic studies within the family have not been undertaken. 

 Thomson's manuscript revision (see Thomson, 1982) recog- 

 nizes 14 genera and 64 species of the nominal 282 species. Of 

 these, 32 are indeterminate because of inadequate descriptions 

 or missing holotypes. The only published world revision, by 

 Schultz (1946), recognizes 13 genera. Relationships are based 

 upon the adipose eyelid, type of scales, labial characteristics, 

 preorbital shape, and type of habitat. Larval mullets have been 

 studied extensively, but not on a worldwide basis, and no phy- 

 letic analysis has been attempted. It is known that in certain 

 species the young stages have 2 anal spines, but larger stages 

 have 3 spines. The younger stages have been referred to as the 



