OLNEY: LAMPRIFORMES 



377 



Fig. 199. Larvae of Slylephorus chordatus. (Upper) 3.8 mm NL, MCZ 59718; (Lower) 7.6 mm SL, MCZ 59719. 



ever, only lophiiform, bothid, zeid and serranid larvae have 

 elongate dorsal and pelvic elements. 



Specialized ink glands filled with dark brown fluid are char- 

 acteristic of lophotid and radiicephalid fishes, and are conspic- 

 uous in larval R. elongatus (Fig. 198), young Lophotus (Fig. 

 201) and presumably Eumectchthys (Walters and Fitch, 1960; 

 Harrison and Palmer, 1968). Although this unpaired, internal 

 structure is not considered a larval specialization, its early ap- 

 pearance in larval R. elongatus and juvenile Lophotus suggests 

 that the ink gland may be functional in young fishes. 



Development from larval to juvenile stages is gradual in Lam- 

 pris (Figs. 196 and 197; Oeschlager, 1976b) but ontogenetic 

 variability is marked and abrupt in trachipterid genera and Sty- 

 lephorus chordatus. This rapid transition from prejuvenile to 

 juvenile morphology has been termed metamorphosis in Des- 

 wof^ewfl (Rosenblatt and Butler, 1977) and Trachlptenis (Huhhs, 

 1925). In D. polystictum. metamorphosis is characterized by 

 changes in ventral profile, elongation of caudal vertebrae, in- 



crease in eye size, eruption of mandibular teeth, and loss of 

 spots, pelvic fins and the posterior nostril (Rosenblatt and But- 

 ler, 1977). Examination of S. chordatus material indicates a 

 similar rapid transition, characterized by the loss of elongate 

 dorsal rays, three ventral caudal rays and stout pelvic elements 

 and by a marked change in eye morphology from a normal, 

 non-telescopic eye to the specialized adult condition (Pietsch, 

 1978a). Similar metamorphic change may occur in other lam- 

 priform taxa, however full developmental series are not avail- 

 able. 



Meristics. — Mtn%X\c variability is useful in delimiting lampri- 

 form taxa (Tables 98, 100). Precaudal, caudal and total vertebral 

 counts distinguish genera and sometimes species (i.e., D. poly- 

 stictum vs D. lorum; T. fuku:aki vs T. altivelis) and total myo- 

 mere counts can be used to identify early larvae (Olney and 

 Naplin, 1980). Total vertebral/myomere counts of less than 53 

 characterize Lampris. Slylephorus and veliferids and are the 



