ONTOGENY AND SYSTEMATICS OF FISHES-AHLSTROM SYMPOSIUM 



Fig. 146. Caudal fin of Brosme hrosme. 45.2 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; PU|„ = Preural 

 centrum 10. (Huntsman Mar. Lab., H 9742, stored at NWAFC). 



grammus) or the presence and distribution of such pigment (e.g., 

 Pollachius virens. P. pollachius) is also of diagnostic value (Rus- 

 sell, 1976; Matarese et al., 1981; Dunn and Vinter, 1984). 



Pigment in the postanal region is also diverse and usually of 

 value in discriminating among species (e.g., Russell, 1976). For 

 purposes of discussion here we divide the gadines into three 

 groups based on their postanal pigment patterns: those genera 

 without postanal pigment bars in preflexion larvae, those genera 

 in which individual species may or may not possess such bars, 

 and those genera possessing one or two postanal pigment bars 

 (Table 79). 



Merlangius and Melanogrammus lack postanal pigment bars 

 (Fig. 149C, D). In Merlangius. postanal pigment develops along 

 the dorsal body midline and extends to nearly three-quarters 

 the length of the body. Ventral pigment consists of a row of 

 melanophores from the anus to the caudal fin. Preflexion larvae 

 of Afelanogratnmus lack the dorsal line of pigment, but possess 

 the continuous ventral line. 



Within Trisopterns and Pollachius, some species have one or 

 two postanal pigment bars, whereas others lack such bars [7'. 

 esmarkii. T. minutus. and P. pollachius (RusseW. 1976)]. In those 

 species possessing postanal bars, T. luscus (Fig. 149 A) has a 

 single pigment bar, with dorsal and ventral midline pigment 

 extending to about one-half the postanal body (Russell, 1976). 

 Pollachius virens (Fig. 149C) has two postanal pigment bars, the 



anterior of which is close to the vent. Of those without pigment 

 bars, T. minutus and P. pollachius possess dorsal and ventral 

 lines of pigment extending to about three-quarters of the body 

 length; caudal peduncle pigment may be present in certain size 

 larvae of the former species, but is normally lacking in the latter. 

 Gadiculus has one postanal pigment bar located posterior to 

 the midpoint of the postanal region whereas Micromesistius has 

 a single bar near the midpoint of this region (Figs. 149F and 

 1 50E). The dorsal stripe is slightly longer than the ventral stripe. 

 Mediolateral pigment between the dorsal and ventral bars de- 

 velops during ontogeny, but the caudal peduncle area is not 

 pigmented. Gadus (in those species whose larvae are known), 

 Microgadus. Eleginus, Boreogadus, and Thcragra have two 

 postanal bars of pigment (not known for Arctogadus) as shown 

 in Figs. 149E and 150A-C. In some genera (e.g., Boreogadus) 

 the dorsal stripe of each bar is longer than the ventral stripe; in 

 others, the ventral stripe is longer than the dorsal (Gadus. Mi- 

 crogadus. Eleginus, and Theragra). The anterior end of the ven- 

 tral stripe may be near the anus (e.g., Gadus), or some distance 

 from It (e.g., Boreogadus). and the ventral stripes may be com- 

 posed of a single row of melanophores on each side of the body 

 midline (e.g., G. macrocephalus), a double row on each side of 

 the midline (E. gracilis), or on the ventral midline with scattered 

 pigment on each side of the body {B. saida). Caudal peduncle 

 pigment may be present or absent. 



