The striped marlin (Kajikia audax) is a species of marlin found in tropical to temperate Indo-Pacific oceans not far from the surface. It is a desirable commercial and game fish. The striped marlin is a predator that hunts during the day in the top 100 m or so of the water column, often near the surface. One of their chief prey is sardines.
The striped marlin consists of 42-48 rays on its tall first dorsal fin that is almost the same or longer than its body depth while the second dorsal fin is much smaller. They have torpedo-like and compressed bodies. They have around 12-20 clear, visible bluish stripes on the sides of their bodies even after death. These stripes can transform in color from blue-tinged to lavender. This occurs when the fish are excited because this state causes specialized pigmentation cells called chromatophores to contract or expand, resulting in a color change.[2] The color of their bodies is dark blue or black above and silvery-white on the bottom. The striped marlin has an average length of 2.9 m (9.5 ft), a maximum length of 4.2 m (13.8 ft) and can weigh up to 220 kg (490 lb).[3]
The striped marlin is widely distributed around the world but is typically found in tropical and/or temperate water bodies.[4] The species is epipelagic, meaning that it resides in the zone that is away from the shore but nearest to the surface of the water.[5] A study on their habitat preferences utilized opportunistic occurrence data to determine that the eastern Pacific Ocean is among the most ideal bodies of water for the striped marlin to inhabit.[6] Additionally, it was discovered that the largest populations of the striped marlin reside in water bodies with dissolved oxygen levels from 4.5-5.5 mL/L and a sea surface temperature between 20 and 28 degrees Celsius.[6]
It was also determined that chlorophyll a levels are of the greatest importance when it comes to striped marlin distribution.[6] High levels of chlorophyll a in a water body are indicative of high productivity, or nutrient level, within that aquatic ecosystem.[7] An abundance of nutrients supports the growth of aquatic plants and algae, which in turn contributes to the congregation of species upon which the striped marlin preys. For this reason, the striped marlin is found in greater amounts in water bodies that contain high levels of chlorophyll a.[6]
The striped marlin has also demonstrated diel vertical migration patterns.[8] A study observed that the striped marlin tends to occupy deep regions of the water during the day. Alternatively, they typically gather near the surface of the water at night. These patterns were prominent in all of the regions tested in the study, including waters off of Australia, New Zealand, Mexico, California, and Ecuador.[8]
The striped marlin reaches sexual maturity at the age of 1–2 years for males and 1.5–2.5 years for females. The striped marlin spawns in multiple batches during the summer, with each spawning season consisting of anywhere from 4 to 41 spawning events because females release their eggs every couple of days. Consequently, the average female striped marlin can produce up to 120 million eggs in any given spawning season.[2] They can live up to 10 years.[9][10]
The striped marlin is a top predator that mainly feeds on a wide range of fish such as sardines, mackerels, small tuna, and cephalopods. One study off the coast of Mexico has found that it feeds mostly on schooling fish such as the Chub mackerel, Etrumeus sadina and Sardinops caeruleus. It also feeds on some species of squid, most commonly the Jumbo Squid.[11]
Striped marlin are protected in the United States by The Billfish Conservation Act of 2012.[12] This act prohibits the distribution or sale of billfish and/or billfish products in addition to their possession with the intent to sell. This law was put into place because there has been a significant downward trend in global billfish populations despite previously enacted management practices, likely due to generalized overfishing. Exemptions to this law include “billfish caught by U.S. fishing vessels and landed and retained in Hawaii or Pacific Insular Areas from the general prohibitions on sale and custody with the intent to sell.” Additionally, “billfish landed by foreign vessels in the Pacific Insular Areas and exported to markets outside the U.S. or retained within Hawaii and the Pacific Insular Areas for local consumption” are exempt.[12]
The overfishing status of the striped marlin varies by geographical region. For instance, the striped marlin population is stable in the Eastern Pacific Ocean but is overfished in the Western and Central North Pacific Ocean. The international conservation efforts for the striped marlin are managed by the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCFPC), whereas the domestic U.S. conservation efforts are managed by the National Oceanic and Atmospheric Administration (NOAA) and the Western Pacific Fishery Management Council.[13]
In 2010, Greenpeace International added the striped marlin to its red seafood list. [14]
Also known as nairagi due to its popularity in Hawaiian markets, the striped marlin is considered a seafood delicacy that is consumed all around the world.[15] It has a flavor that is comparable to but stronger than swordfish.[13] Its firm meat can range from light pink to orangish red in color.[13] Striped marlin is generally enjoyed in a grilled form, but it can also be fried, smoked, baked, or eaten raw.[2] Typical of other fish species, the striped marlin is an ideal source of omega-3 fatty acids and other essential vitamins and minerals. Also, it is a lean source of protein with minimal sodium and low levels of saturated fat, making it a practical choice for a nutritious meal.[13]
{{cite journal}}: CS1 maint: uses authors parameter (link) The striped marlin (Kajikia audax) is a species of marlin found in tropical to temperate Indo-Pacific oceans not far from the surface. It is a desirable commercial and game fish. The striped marlin is a predator that hunts during the day in the top 100 m or so of the water column, often near the surface. One of their chief prey is sardines.
