Splitnose Rockfish

Sebastes diploproa

Splitnose Rockfish

Sebastes diploproa

Other Common Names
Lobe-jawed rockfish, splitlip rockfish, rosefish

Sandy Coast

Other Common Names

Lobe-jawed rockfish, splitlip rockfish, rosefish

At the Aquarium

Sandy Coast

Appearance

Splitnose rockfish are named for the deep notch in the upper jaw. Their bodies are a pale pink or light orange with patches and bars of darker pinks, reds, and oranges on the back, head, and fins.

Habitat

Over muddy bottoms on the outer shelf and slope, subtidally to 2,600 feet. Juveniles are often found in shallow waters, under vegetation.

Diet

Plankton; euphasiids, copepods, sergestid shrimps, and amphipods.

Life History

Females give live birth, with larger females producing many more larvae. A 7.5 inch female will birth to ~14,000 young while a 14.5 inch female will birth to ~255,000 young. In Oregon, females typically give birth mid-May to June. Larvae start life as plankton, just 0.2 inches long. After a year, they may then settle to shallow, nearshore habitats, and will use mats of entangled kelp as drifting habitats for several months. Can live up to 100 years and lengths of 18 inches.

IUCN Status

Not Evaluated

Ecosystem & Cultural Importance

These fish are important to marine food webs. Their predators include giant squid and the Humboldt squid (Dosidicus gigas).

Alaska to Baja California

Splitnose Rockfish are considered a slope rockfish species, since they tend to hang out in deeper waters on the continental shelf. They are one of the 25 commercially-landed rockfish species for Oregon.

These fish can either be found alone resting on the seafloor, or with other fish schooling above the bottom. Juvenile splitnose rockfish use drifting vegetation mats as mobile nurseries. These mats drift in open waters, pushed by winds and tides, and have many tiny organisms living within them. They provide the rockfish with food, and cover from predators such as birds and larger fish.

Citations & Other Resources

Oregon Department of Fish and Wildlife website: https://www.dfw.state.or.us/mrp/finfish/sp/rockfish.asp
Pacific Coast Groundfish Fishery Management Plan https://www.pcouncil.org/documents/2019/06/groundfish-fmp-appendix-b-part-2.pdf/ Gertseva, Vladlena V., Jason M. Cope, and Sean E. Matson. inchesGrowth variability in the splitnose rockfish Sebastes diploproa of the northeast Pacific Ocean: pattern revisited.inches Marine Ecology Progress Series 413 (2010): 125-136.
Palsson, Wayne A., et al. inchesThe biology and assessment of rockfishes in Puget Sound.inches Washington Department of Fish and Wildlife Report FPT-09-04 (2009).
Sanctuary Science Website: Pearse et al. (2008). inchesApplication of molecular genetic methods to rockfish predation and habitat association research efforts in Central California.inches Southwest Fisheries Science Center, NOAA Fisheries; https://sanctuarysimon.org/regional_docs/monitoring_projects/100338_Pearse_etal_2008.pdf
Shaffer, J. Anne, et al. inchesCrustacean community composition and trophic use of the drift vegetation habitat by juvenile splitnose rockfish Sebastes diploproa.inches Marine Ecology Progress Series 123 (1995): 13-21.
Washington Department of Fish and Wildlife: https://wdfw.wa.gov/species-habitats/species/sebastes-diploproa#desc-range

Splitnose Rockfish

Splitnose Rockfish

Other Common Names

At the Aquarium

Appearance

Habitat

Diet

Life History

IUCN Status

Ecosystem & Cultural Importance

Citations & Other Resources

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