The yelloweye rockfish is one of the biggest and longest-lived marine species in the ocean. They are known for their distinctive appearance. However, they are now at risk due to human activities. Let’s dive into fascinating facts about these remarkable fish and discover why they are sought after so much.
1. They are one of the biggest fish
The yelloweye rockfish is one of the biggest species in the rockfish family. It can reach a length of up to 3 feet (90 cm) and a weight of up to 25 pounds (11 kg), with females generally being bigger than males. Its average size is from 5 to 15 pounds (2.26 – 6.8 kg). The largest world record yelloweye rockfish weighed 39 pounds (17.6 kg) and had a size of 3 feet in length.
Despite being commonly referred to as red snapper by anglers, it has no relation to the true red snapper found in the Gulf of Mexico.
The yelloweye rockfish acquired its name from its striking yellow eyes. Besides this feature, these fish also stand out for their vibrant orange-red to orange-yellow body. Interestingly, this color changes when they get older.
Yelloweye fish exhibit a color transformation throughout their lifespan. When they are young, the color starts with a deep reddish tint. Then it transitions to a brighter orange as they mature, and finally reaching a deeper yellow in their later years.
These creatures may have black fin tips. They also have multiple little spines on their head, the large adults have a raspy ridge. There’s a line with brighter color along the lateral line of their body.
Juveniles and adults have quite distinct appearances. The young yelloweye rockfish have a darker red color and two white stripes running parallel to their lateral line. Their fins may be tipped in either white or black.
2. Habitat and Distribution
The North Pacific contains 100 species of rockfish, 32 of which are located in Alaskan regions. The yelloweye rockfish is a common species that can be found along the West Coast of North America, ranging from the Gulf of Alaska to northern Baja California, Mexico.
Depending on the age, these fish will live at different depths, ranging from 48 – 1,800 feet (14 – 548 meters). Adults are solitary creatures and reside at depths ranging from 300 to 600 feet (91 – 183 meters). On the other hand, younger ones typically live in shallower areas (60 feet/18 meters) and move deeper when they grow up.
Yelloweye rockfish are known for their preference for rocky habitats with crevices and boulder fields on the ocean floor. They barely go far from home. Some of them have been known to spend their whole lives in a single rock pile.
3. Yelloweye rockfish Diet
Yelloweye rockfish are commonly seen searching for food on the seafloor. Yelloweye larvae eat small crustaceans, algae, and other single-celled organisms.
As they mature, their dietary habits change and they start preying on a wider range of creatures. These predatory fish consume crustaceans, other bottom-dwelling invertebrates, other rockfish, other smaller fish, juvenile groundfish, and herring.
They are eaten by salmon and other marine fish and seabirds.
4. Their protruding eyes only show up when on land
These rockfish don’t have a vent on their swim bladder. The swim bladder, a balloon-like structure, is used to regulate the fish’s buoyancy. If the bladder is not vented, yelloweye pulled up from deep waters can experience injury since the air in the bladder expands.
This can cause the eyes to bulge and the stomach to protrude from the mouth, as well as internal injuries that are not visible. If you release the fish back into the ocean, you put them at risk. A bloated swim bladder prevents yelloweye from diving, leaving them vulnerable to predators while they float on the surface.
This characteristic contributes to the yelloweye’s fragility.
Since the air expanding in the bladder is the reason, some people may puncture the stomach that protrudes from the mouth to help them submerge. However, this is not recommended as it often causes them to die later.
5. They have a really long lifespan
Yelloweye rockfish, like all other rockfish species, have a slow growth rate and long lifespan. This makes their recovery from human effects difficult. Male Alaska yelloweyes reach maturity around the age of 18, while females mature at 22 years old.
The mating season of these species often occurs in November. Females are able to store sperm for several weeks or even months before fertilizing the eggs. And they can release a large number of eggs every year, ranging from 1.2 to 2.7 million. The bigger and older females are, the more eggs they can produce.
These yelloweye fish will go through a gestation period of one to two months. Yelloweye rockfish are viviparous, they will give birth to live young, instead of laying eggs. This internal fertilization protects the eggs within the mother’s body.
Female yelloweye give birth to live offspring from April to September, with the highest rate of births occurring in the spring months of May and June.
During their larval stage, which lasts for six to nine months, the young fish float in the open ocean. They are vulnerable to various environmental factors such as currents, temperature, and food availability. Only a limited portion of these larvae will successfully survive to adulthood.
After 6 to 9 months, when the young yelloweye reach a certain size (approximately 3 to 10 centimeters), they swim down to the ocean floor where they will remain for several years. Juveniles and subadults prefer shallower water near rocky reefs and kelp canopies. As they mature, they will eventually go to deeper areas and choose rocky bottoms for their habitat.
Despite their slow rate of maturation, yelloweye fish have one of the longest lifespans among fish. There are some reports of individuals living up to 114 to 130 years old. Why do these yelloweye rockfish live so long? There’s a reason for this.
In a study, scientists found out that these rockfish have genes that are capable of repairing DNA. The researchers discovered that these genes undergo rapid mutations, which could potentially protect the fish from developing cancer when they get older.
Additionally, the study revealed that species of rockfish with longer life spans have a greater number of copies of genes in the butyrophilin family. These genes play a crucial role in reducing inflammation and controlling the onset of inflammatory diseases in both fish and humans. Furthermore, they help regulate insulin and glucose levels, which are essential factors in energy metabolism for both fish and humans.
The yelloweye rockfish species are highly susceptible to overfishing, including indigenous, commercial, and recreational fisheries. They are caught both as a targeted species and as bycatch in various fishing methods such as the salmon troll or prawn trap.
In response to the drastic decline in yelloweye populations, conservation measures were implemented in the early 2000s. This involves lowering the total permissible and establishing Rockfish Conservation Areas (RCA).
The regulations are tougher. In Washington State, many commercial fishing practices that caught rockfish as bycatch were closed and there is no direct commercial harvest of yelloweye in Puget Sound. Recreational fishing for yelloweye is also prohibited in Puget Sound waters east of Port Angeles. In California, it’s illegal to catch, own, keep, buy, or sell yelloweye fish.