Like the other thresher sharks, nearly half its total length consists of the elongated upper lobe of the tail fin.

To protect its sensitive brain and eyes from the temperature changes accompanying these movements, the bigeye thresher has a vascular exchange system called the rete mirabile around those organs.

This shark is caught by commercial fisheries across its range; the meat is not highly regarded but the skin, fins, and liver oil are valued.

[8] Fossil remains of the bigeye thresher dating to the Middle Miocene (16.0–11.6 Ma) have been found in the Hokuriku region of Japan.

In the western Atlantic Ocean, it has been reported from New York to Florida, the Caribbean, Venezuela, Tobago and southern Brazil.

[9] Bigeye threshers are usually found over the continental shelf and in the open sea, though they are occasionally encountered in shallow coastal waters.

[6][10] Little is known of their geographical movements; one individual has been documented moving from New York to the Gulf of Mexico, a straight-line distance of 2,767 km (1,719 mi).

[7] The largest known bigeye thresher measured 4.9 m (16 ft) long and weighed 364 kg (802 lb), and was caught near Tutukaka, New Zealand, in February 1981.

[12] The size and upward orientation of the bigeye thresher's eyes are adapted to search for the silhouettes of prey in dim light.

The bigeye thresher appears to be an ecological competitor of the blue shark (Prionace glauca), and the numbers of the two species are negatively correlated such as that only one of two occurs in any given location.

The developing fetuses are initially nourished by a yolk sac, and later on exhibit oophagy, in which they consume infertile eggs produced by their mother (and possibly also uterine fluid).

They are covered with a thin layer of epithelium that prevents the uterine wall from being abraded by the embryo's sharp dermal denticles; this has not been observed in the young of other thresher sharks.

In a 1971 study, Carey et al. probed the swimming muscles of two bigeye threshers with a thermistor needle and reported finding a temperature elevation of 1.8 and 4.3 °C (35.2 and 39.7 °F) compared to the ambient environment.

There is also no blood vessel countercurrent exchange system (the rete mirabile) in the trunk to limit the loss of metabolic heat to the water.

Based on these differences, the authors questioned earlier measurements and concluded it was unlikely that the bigeye thresher maintains an elevated body temperature.

This species is or was taken by longline fisheries operated by many countries, including the United States, Japan, Spain, Brazil, Uruguay, and Mexico, and constitutes about 10% of the pelagic shark catch.

The bigeye thresher comprises 20% of the longline catch off Cuba, where it is attracted at night using cyalume sticks (chemical lights).