452 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Body Proportions 



Thirteen body proportions were measui'ed on 27 

 specimens from 82.5 to 204.0 mm. (figs. 9 through 



21). 



There is possibly a slight inflection between 150 

 and 180 mm. for interorbital space (fig. 18), with 

 a suggestion of a lower rate of increase beyond the 

 inflection than initially. The other characters 

 show a constant rate of increase within the size 

 range of available material. 



Pigmentation 



Specimens up to 122 mm. that were preserved 

 in alcohol were either pale yellow overall or yellow 

 with silvery abdomen and sides up to the lateral 

 midline. Above this size, the colors were dark 

 to light tan or yellow. Some retained red on the 

 head and anteriorly on the lateral midline. Two, 

 174.5 and 188.0 mm., were tan with dark lateral 

 midlines. Fins were clear on all specimens. 

 Fins 



Spinous dorsal. — The literature is conflicting in 

 regard to the number of spines. Opinion is about 

 equally divided as to whether there are 7 spines 

 (Cuvier and Valenciennes, 1829; Storer, 1846; 

 Meek and Hildebrand, 1923 ; Beebe and Tee- Van, 

 1933) or 8 (Jordan and Evermann, 1896; Nichols, 

 1929; Evermann and Marsh, 1902). An exami- 

 nation of 27 specimens of the species explains the 

 divergence of opinion. Visual examination shows 

 some have a spiny protuberance resembling a very 

 short spine at the origin of the 1st dorsal. If 

 the area is carefully probed, some specimens show 

 this structure embedded and on others probing 

 reveals nothing (fig. 40). Wlien present, the 

 spiny protuberance is usually movable in all direc- 

 tions. A cleared and stained spinous dorsal fin 

 of a 138.5-mm. specimen (fig. 41) shows the struc- 

 ture, completely covered by soft tissue. 



I X-rayed similar-sized specimens of the four 

 species of western North Atlantic Mullidae to 

 observe the bony structure anterior to the spinous 

 dorsal, seen on some, but not all, species (fig. 42). 

 X-ray evidence points to an intergrading of this 

 character between species. The species are ar- 

 ranged from top to bottom in the X-ray positive 

 in ascending order of magnitude of the bony 

 structure. 



In U. parvus (106.0 mm.) the spiny protuber- 

 ance at the origin of the first dorsal fin was small, 

 round and well covered with soft tissue. The 



I { 



Figure 40. — SpinoiLs dorsal fln of 83.5-min. Mulloidichthys 

 martinicus. Line equals .5 mm. 



Figure 41. — Cleared and stained spinous dorsal fin of 

 138.5-mm. Mulloidichthys martinicus. Upper: lateral 

 view ; lower: dorsoventral view. Line equals 2 mm. 



interneurals numbered three and were set well in 

 advance of the spines. 



In M. martinicus (105.5 mm.) the structure was 

 small, pointed obliquely up and back, and was 

 covered with soft tissue. The interneurals num- 

 bered three (first not dense), and were set well in 

 advance of the spines. 



In M. auratus (105.5 mm.) the structure gave 

 tlie appearance of a rudimentai-j' spine. The in- 

 terneurals numbered three and were not placed as 

 far forward as in the two previously mentioned 

 species. The spine i^rotruded from the soft tissue. 



In P. maculatus (106.5 mm.) the structure gave 

 the appearance of a rudimentary spine, slightly 

 larger than that of M. auratus. It projected well 

 beyond the soft tissue. What appeared in the 



