298 



ONTOGENY AND SYSTEM ATICS OF FISHES- AHLSTROM SYMPOSIUM 



Hy4-6 



Fig. 151. Caudal fin o( Microgadus proximus, 41.1 mm SL. Hyl = Hypural bone 1; Hy2-3 = Hypural bones 2 and 3; Hy4-6 = Hypural bones 

 4, 5, and 6; EP, = Epural bone 1; EP, = Epural bone 2; U, = Ural centrum 1; U, = Ural centrum 2; PU, = Preural centrum 1; PUk, = Preural 

 centrum 10 (after Matarese et al., 1981). 



Lotinae lai-vae are relatively elongate and somewhat narrow 

 at the pectoral fin base; the former state is partially due to their 

 numerous vertebrae (Table 78). In contrast, phycines are shorter 

 and stockier in appearance, deep bodied at the pectoral fin base, 

 and morphologically somewhat resemble scorpaeniform larvae. 

 Ramceps larvae are morphologically the most divergent, ap- 

 pearing tadpole shaped due to their depth at the pectoral fin 

 base. Gadines are somewhat shorter in appearance, and deeper 

 bodied, than lotines, but morphologically intermediate between 

 phycines and lotines. Merluccius larvae are similar to gadines 

 in overall shape (Fig. 143D in Fahay and Markle, this volume). 



Length at hatching is smallest in most phycines and somewhat 

 larger in Raniceps. lotines, and gadines (Table 78). Notochord 

 flexion occurs at quite small sizes in phycines (except in Ran- 

 iceps), relatively larger sizes in lotines, and intermediate sizes 

 in gadines. A silvery prejuvenile stage is present in phycines 

 (not recorded for Raniceps), but a pelagic stage of varying du- 

 ration (Table 78) is probably present in all gadid larvae (Fahay 

 and Markle, this volume). Merlucciiis hatches at moderate lengths 

 (2.6-3.8 mm; Ahlstrom and Counts, 1955; Russell, 1976; Fahay, 

 1983), notochord flexion begins at about 9 mm, and transfor- 

 mation begins at 20-25 mm, somewhat similar to gadines. Elon- 

 gate pelvic fins develop precociously in all lotines (except Lota) 

 and phycines, but not in gadines. Pelvic fins in Merluccius are 

 shorter than in phycines. but longer than in gadines. Fahay and 

 Markle (this volume) noted similarities in fin development be- 

 tween Merluccius and gadines in that the caudal develops first. 

 In gadines, however, the pelvic fins develop last. In Merluccius. 

 it is the second fin to develop. 



Pigment patterns are shared by Brosme and Molva. but not 

 Lota, whose pigment resembles certain gadines (e.g., Pollachius 

 pollachius, Trisopterus minutus). Two kinds of pigment patterns 

 have been identified for phycines: either dorsal saddles of pig- 

 ment in the postanal region (Enchelyopus cimbrius, Gaidrop- 



sarus mediterraneus. Urophycis chuss) or a ventral series of me- 

 lanophores (Phycis blennoides, Ciliata. and Raniceps). Gadines 

 have either one or two postanal bars or dorsal and ventral lines 

 of pigment. In gadines the pelvic fins lack pigment such as that 

 present in lotines and phycines. In comparison, Merluccius has, 

 in certain species (e.g., M. product us. Ahlstrom and Counts, 

 1955), a single postanal band of pigment, but two in M. albidus 

 and M. hilinearis (Fahay, 1983) and three lateral melanophores 

 (M. merluccius. Russell, 1976). Pelvic fins are pigmented in 

 some Merluccius. 



Lotines have one (Brosme) or two (Moha. Lota) dorsal fins; 

 when two fins are present, they are internally continuous (Mar- 

 kle, 1982). Phycines have two dorsal fins, the first specialized 

 (Cohen and Russo, 1979), and are internally continuous (Mar- 

 kle. 1982). Gadines have three dorsal fins, of which the second 

 and third are always internally continuous. The posterior mar- 

 gins of the dorsal and the anal fins are close to the procurrent 

 rays of the caudal fin in lotines and phycines, whereas in gadines 

 these fins are generally some distance from the caudal fin, as is 

 the case in Merluccius (Fahay and Markle, this volume). 



Certain trends in osteological structures can be noted in the 

 family Gadidae. Transient pterotic spines are present in some 

 phycines (some f/!i'ai. Gaidropsarus. Markle, 1 982) and Ciliata 

 (this study), and are lacking (so far as is known) in other phy- 

 cines, lotines, gadines, and in Merluccius. The distribution of 

 branchiostegal rays varies among gadid genera. The seven bran- 

 chiostegal rays in Brosme are carried on the outer surface of the 

 ceratohyal, whereas in Gadus and Lota (Mujib, 1967, 1969). as 

 well as in Theragra (Dunn and Vinter, MS), the three anterior 

 rays are internal and the posterior four are external. Raniceps 

 has one branchiostegal ray on the epihyal, a character considered 

 primitive and shared (so far as known) with Urophycis chuss 

 and Merluccius (Mujib, 1967; Inada, 1981b), whereas gadines 

 have all seven branchiostegal rays on the ceratohyal (this study). 



