User:Sowhatsthesitch/Sebastes emphaeus

= Puget Sound rockfish = The Puget Sound rockfish (Sebastes emphaeus) is a species of rockfish that is native to the northeast Pacific.

Description and anatomy
The Puget Sound rockfish is mainly copper-red in color with blotches of greenish brown. Unlike some other species of rockfish, it has no dark blotch at its spinous dorsal fin. It can also be differentiated from other similar-looking rockfishes, such as the pygmy rockfish, by its lack of both a reddish brown stripe and dark patches below the lateral line. The Puget Sound rockfish’s spinous dorsal fin is green, and its soft, rayed dorsal fin and caudal fin are also mostly dark. These fins are brimmed with red at the tips. Compared to the other fins, the pectoral and anal fins are more translucent, appearing clearer and pinker. Typically, the soft dorsal fin has 14 to 15 rays, the soft pectoral fin has 17 to 18 rays, and the soft anal fin has 7 to 8 rays. Green stripes extend from the eyes, between which the fish’s head shape is convex. Puget Sound rockfishes have strong head spines, but no supraocular spines. The peritoneum is dark in color.

In comparison to other rockfish species, the Puget Sound rockfish is significantly smaller in size and can be considered a dwarf species. An adult of 3 to 5 years in age averages around 13 to 16 centimeters in length, and older adults can reach body lengths of up to only 18 centimeters.

Distribution and habitat
The Puget Sound rockfish is found along the west coast of North America, from northern California to the Gulf of Alaska. It appears in abundant populations around the San Juan Islands and Puget Sound, Washington, lending to its name.

Puget Sound rockfishes typically inhabit areas with strong currents and hard substrate and are found at depths ranging from 10 to more than 300 meters. They tend to rest near the bottom of the water column, in crevices of rocks, or inside caves. Once young rockfishes find a place to settle, they tend to stay there throughout adulthood.

Between the 1960s and 2000s, multiple rockfish species suffered significant population declines due to overfishing. On the contrary, Puget Sound rockfish populations grew rapidly during this time, particularly in the 1990s. Due to their small size, Puget Sound rockfishes were not as desirable for commercial or recreational purposes and were mostly spared from fishing. For this reason, along with other rockfish populations shrinking, and the lingcod, a major predator of the Puget Sound rockfish, also being overfished, Puget Sound rockfish populations expanded. As a result, they also experienced slower growth rates during this time due to heightened intraspecific competition for food and space. Genetic evidence also suggests that the Puget Sound rockfish population increase could have started as early as 12,000 years ago during the postglacial period.

Biology
Female Puget Sound rockfishes reach reproductive maturity at around two years of age. The spawning season for the Puget Sound rockfish lasts for only nine days from late August to early September. It is shorter and occurs later in the year than spawning seasons for most rockfish species. Female Puget Sound rockfishes are livebearers and have a gestation period of 30 days, after which they give live birth. They have relatively high fecundity, with each female producing up to 57,000 eggs per season. The brief gestation period and overabundance of spawn imply little parental involvement in the children's lives after birth.

Sebastes emphaeus is a schooling species, and young Puget Sound rockfishes are mostly found in schools, with which they find a place to settle down for the remainder of their lifespans. They can live for up to 22 years, which is relatively short in comparison to other rockfish species. As a result, they also have a higher mortality rate. They are opportunistic feeders and mostly feed on little creatures, such as small plankton, amphipods, and fish larvae. They are fed on by larger creatures, including larger rockfish species. As a consequence of their body size being smaller than that of other species of the genus Sebastes, they are more often preyed on by the lingcod, a common predator in the Puget Sound area.

The protozoan parasite Ichthyophonus infected about 11% of Puget Sound rockfishes in 2003. It was found that infection was more common in females than in males, and unlike in other afflicted species, the parasites do not leave white marks on the Puget Sound rockfish.

Taxonomy
Other species of the genus Sebastes that Sebastes emphaeus is closely related to include S. variegatus (harlequin rockfish) and S. zacentrus (sharpchin rockfish).