126 CALIFORNIA FISH AND GAME. 
dorsal is high and triangular, and has about eight spines. The front 
of the second dorsal and anal are high and pointed. The anal is pre- 
ceded by two strong spines and is behind the front of the second dorsal. 
Be NOD) MD a» Dy 
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ae NS hareee tang 
Fig. 71. The horse mackerel (Trachurus symmetricus). 
The pectoral fin reaches to or a little past the anal spines. The back 
is greenish shading downward to silvery on the lower parts. 
The horse mackerel is found abundantly from San Francisco south- 
ward. As a food fish it is inferior to the mackerel, being rather coarse 
fleshed. Little has been done in preserving it. 
THE MARLIN-SPIKE FISHES. 
(Family Istiophoridea. ) 
In this family are the sailfishes (/stiophorus), and spearfishes of 
the Atlantic, and the marlin-spike fishes of the Pacific. The spearfishes 
and marlin-spike fishes belong to the same genus (Z'etrapterus) though 
of different species. The fishes of this family differ from the true 
swordfishes in having small granular teeth in the mouth, in having 
ventral fins, and in having two keel-like projections on each side of 
the tail. 
The Marlin-Spike Fish (Tetrapterus mitsukurii). 
This species may be known by its upper jaw being prolonged into a 
““sword’’ together with its having long vcntral fins composed of one 
ray each. The first dorsal fin is high in front where it rises to a point, 
Fig. 72. The marlin-spike fish (Tetrapterus mitsukurii). 
and is as high or a little higher than the depth of the body. The dorsal 
quickly becomes lower and runs for nearly the whole length of the back 
as a low fin, gradually growing lower and disappearing. The second 
dorsal is small and short; the front of it elevated to a point. The pee- 
toral fin is about as long as the dorsal is high. The anal fin is divided 
