MASTERS OF THE WATER-BONY FISHES 209 



As a group, identification is rather easy, there being a series of small finlets 

 behind the soft dorsal and anal fins. The shape does not vary much from a 

 torpedolike spindle, the caudal peduncle being very slim and supported by 

 strong lateral keels. The colors are primarily silvery with blue or green and some 

 yellow markings. 



These and the spearfishes are the swiftest of the swift. A speed of 40 to 50 

 mph is probably attained by the larger species. The body is very smooth, even 

 the eyes and gill cover being practically flush with the extremely powerful 

 body. Among the fishes, these are the wolves of the sea, running down prey. A 

 few, however, are plankton eaters. Most are primarily pelagic and wandering, 

 coming inshore when the seas are calm and warm. In most, the pattern and 

 causes of migration and the breeding habits are not well known. 



COMMON ATLANTIC MACKEREL: Scomher scomhriis—Color Plate 2 



Size: Averages a little over 1 foot. Up to 2 feet. 



Weight: Averages a little over a pound. Up to 7 pounds. 



Distribution: In the North Atlantic from Labrador to Cape Hatteras and from 

 Norway to Spain. 



Identification: Its small size and the wavy blue markings on the back serve 

 to identify it. 



Habits: Contrary to most of the family, this is a plankton feeder primarily, 

 though many small fishes are also eaten. The long gill rakers serve to strain small 

 animals from the water. The schools are especially large, and they move in 

 response to temperature. The northerly migration begins at Cape Hatteras 

 in March and ends at the St. Lawrence by June. This migration is a coastal 

 one. In the fall, the southerly migration is offshore and in deeper waters. 

 Mackerels produce huge numbers of floating eggs, up to 500,000 per female, 

 in the summer. The mackerel's enemies are many. In the north the gannets, 

 among the birds, take a heavy toll. Many fishes and squid prey upon the young. 



Similar Species: The Atlantic chub mackerel, Pneuvratofhonis colias, is very 

 similar in appearance to the common mackerel, but the wavy lines on the back 

 are about twice as fine and numerous, and the size is smaller, rarelv being over 

 1 foot or 14 inches. It is found from the St. Lawrence south to Virginia. 



The Pacific mackerel, Pneinnatophorus japonicns, is very similar to the chub. 

 It is found from Alaska to Baja California and is abundant from Monterey Bay 

 southward. It reaches 20 inches. 



The frigate mackerel, Aiixis thazard, is a species found in all warm seas, 

 reaching northward to Cape Cod and probably to southern California. There 

 are onlv a verv few fine wavv marks on its back. It reaches 14 inches in lenoth. 



SPANISH MACKBREh: Scoinberomoriis inacidatns— Color Plate 2 



Size: Averages 18 inches. Up to 4 feet. 



Weight: Averages 2 pounds. Up to 20 pounds. 



Distrihittion: Tropical waters from Cape Hatteras to Brazil. Straggles to Maine. 



Identification: This is among the slimmest and most beautiful of mackerels. 

 The head is comparatively small and the body rather compressed. The color 

 is silvery with blue-green above and large yellow spots on the sides. 



Habits: This fish is found inshore in shallow waters in late summer, when it 



