- Although the flesh of the almaco jack is considered quality table fare, the species has been associated with ciguatera poisoning, a seldom fatal stomach irritation.
- The almaco jack is susceptible to tapeworm parasites in the caudal peduncle area, but the meat can be eaten safely if affected portions are cut away.
White marlin (Tetrapturus)
White marlin are the smallest of the marlin species. Yet, like the rest of the marlin family, they are highly regarded game fish. Although somewhat comparable in color to blue marlin, the white marlin can be distinguished from the blue, as they tend to be lighter in color and shaded more with green. The back and upper body of the fish is blue-black to chocolate brown in color, often with a definite green tint. The sides are silver-white with a smattering of brown, especially close to the lateral line. The belly is silver to white in color. The body may have up to 15 vertical white or light blue stripes. These stripes are not very distinct. The dark blue first dorsal fin has black dots between the rays. The other fins are dark blue to black-brown in color.
The body of the white marlin is long, trim and densely covered with distinct pointed scales. The single lateral line is clearly visible as it curves from above the pectoral fin and continues straight along the body to the base of the caudal fin. The upper jaw terminates in the characteristic marlin spear. The lower jaw is straight.
There are two notched dorsal fins, the first one being prominent like that of other marlin, with the highest point near the head and curving downward as it extends to the posterior end. This first dorsal fin has 43 to 52 rays, is retractable and is rounded. The two pectoral fins are flat and can be folded tightly against the body. They have 18 to 21 rays. The anal fins have 17 to 23 rays and the first anal fin has a rounded tip. The caudal fin is large and crescent shaped.
White marlin can also be distinguished from other marlin, particularly blue marlin, by the rounded tips of the dorsal, anal and pectoral fins.
White marlin are aggressive, opportunistic feeders that seem willing to eat whatever is available in their environment. Their diet is likely dependent on their location and the availability of food sources. They seem to do most of their feeding during the day, feeding in both deep and shallow water, especially near underwater canyons, shoals and other areas with steep drop offs. Like other marlin, they use their long spear to stun their prey. The majority of their diet consists of fish such as herring, jacks, mackerels, triggerfish, dolphin fish and flying fish. However, squid and crabs can make up a significant portion of their diet.
Highly migratory, this marlin seeks warm offshore waters in the Atlantic Ocean. They move from area to area in order to stay within temperatures from 68 and 84 F, which leads them to higher latitudes during summer and lower latitudes during winter. They are abundant in the temperate and subtropical areas of the Atlantic Ocean and Caribbean Sea. Geographically, their range extends from 45 degrees north to 45 degrees south latitude in the western Atlantic and from 45 degrees north to 35 degrees south latitude in the eastern Atlantic. This area includes the east coast of the United States down to the southern tip of South America, and from France to the southern tip of Africa. Occasionally, a white marlin will wander into the Mediterranean Sea.
Preferring the deep, blue, temperate to tropical water above the ocean thermocline, white marlin normally roam the ocean at depths between 300 and 500 feet. They are well adapted to areas of low oxygen levels and high salinity. They also seem to congregate near currents with speeds between one and 3 miles per hour.
While distribution and location are closely linked to temperature, they are also influenced by sea floor topography. White marlin are found in largest numbers around steep drop offs near the edge of the continental shelf and around oceanic mountains and canyons. They also like rips, the areas linking different bodies of water.
While they are primarily deep-water fish, white marlin will frequently come into water as shallow as 50 feet, especially around debris or floating weeds. They sometimes travel in small schools of 5 to 12, especially when feeding on baitfish, but usually travel alone or in pairs.
- White marlin fry and juveniles are frequently the prey of large fish, especially shark.
- In addition to being a popular sport fish, white marlin are sought commercially for their good quality meat. Fresh white marlin is especially popular in Mediterranean areas.